29 CFR 1910 (continued, Section 1910.100 to end)

Transcription

codeof
federalregulations
Labor
29
PART 1910 (§ 1910.1000 to
END)
Revised as of July 1, 1999
CONTAINING
A CODIFICATION OF DOCUMENTS
OF GENERAL APPLICABILITY
AND FUTURE EFFECT
AS OF JULY 1, 1999
With Ancillaries
Published by
the Office of the Federal Register
National Archives and Records
Administration
as a Special Edition of
the Federal Register
U.S. GOVERNMENT PRINTING OFFICE
WASHINGTON : 1999
For sale by U.S. Government Printing Office
Superintendent of Documents, Mail Stop: SSOP, Washington, DC 20402–9328
Table of Contents
Page
Explanation ................................................................................................
v
Title 29:
Subtitle B—Regulations Relating to Labor (Continued):
Chapter XVII—Occupational Safety and Health Administration,
Department of Labor ...................................................................
5
Finding Aids:
Material Approved for Incorporation by Reference ............................
541
Table of CFR Titles and Chapters .......................................................
543
Alphabetical List of Agencies Appearing in the CFR .........................
561
Table of OMB Control Numbers ..........................................................
571
List of CFR Sections Affected .............................................................
573
iii
Cite this Code: CFR
To cite the regulations in
this volume use title,
part and section number. Thus, 29 CFR
1910.1000 refers to title
29, part 1910, section
1000.
iv
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v
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vi
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July 1, 1999.
vii
THIS TITLE
Title 29—LABOR is composed of nine volumes. The parts in these volumes are
arranged in the following order: parts 0–99, parts 100–499, parts 500–899, parts 900–
1899, parts 1900–1910.999, part 1910.1000–End, parts 1911–1925, part 1926, and part 1927
to end. The contents of these volumes represent all current regulations codified
under this title as of July 1, 1999.
The OMB control numbers for title 29 CFR part 1910 appear in § 1910.8. For
the convenience of the user, § 1910.8 appears in the Finding Aids section of the
volume containing § 1910.1000 to the end.
Redesignation tables appear in the Finding Aids section of the eighth volume.
Subject indexes appear following the occupational safety and health standards
(part 1910), and following the safety and health regulations for: Longshoring (part
1918), Gear Certification (part 1919), and Construction (part 1926).
For this volume, Shelley C. Featherson was Chief Editor. The Code of Federal
Regulations publication program is under the direction of Frances D. McDonald,
assisted by Alomha S. Morris.
ix
x
Title 29—Labor
(This book contains Part 1910 (§ 1910.1000 to End))
SUBTITLE B—REGULATIONS RELATING TO LABOR (Continued)
Part
CHAPTER XVII—Occupational
Safety and Health Administration, Department of Labor ................................................. 1910
CROSS REFERENCES:
Railroad Retirement Board: See Employees’ Benefits, 20 CFR Chapter II.
Social Security Administration, Department of Health and Human Services: See Employees’ Benefits, 20 CFR Chapter III.
EDITORIAL NOTE: Other regulations issued by the Department of Labor appear in 20 CFR
Chapters I, IV, V, VI, VII and IX; 29 CFR Subtitle A, Chapters II, IV, V, XXV; 30 CFR Chapter
I; 41 CFR Chapters 50, 60, and 61; 48 CFR Chapter 29. For Standards for a Merit System of
Personnel Administration: See 5 CFR Part 900.
1
Subtitle B—Regulations
Relating to Labor
(Continued)
3
CHAPTER XVII—OCCUPATIONAL SAFETY
AND HEALTH ADMINISTRATION,
DEPARTMENT OF LABOR (Continued)
EDITORIAL NOTE: Chapter XVII is continued in the volumes containing 29 CFR Parts 1911
to 1925, Part 1926, and Part 1927 to End.
Part
1910
Page
Occupational safety and health standards (continued) ......................................................................
7
Subject index for 29 CFR part 1910—Occupational
safety and health standards .................................
499
5
All of subpart Z issued under sec. 6(b) of
the Occupational Safety and Health Act, except those substances that have exposure
limits listed in Tables Z–1, Z–2, and Z–3 of 29
CFR 1910.1000. The latter were issued under
sec. 6(a) (29 U.S.C. 655(a)).
Section 1910.1000, Tables Z–1, Z–2 and Z–3
also issued under 5 U.S.C. 553, Section
1910.1000 Tables Z–1, Z–2, and Z–3 not issued
under 29 CFR part 1911 except for the arsenic
(organic compounds), benzene, and cotton
dust listings.
Section 1910.1001 also issued under section
107 of the Contract Work Hours and Safety
Standards Act (40 U.S.C. 333) and 5 U.S.C. 553.
Section 1910.1002 not issued under 29 U.S.C.
655 or 29 CFR part 1911; also issued under 5
U.S.C. 553.
Sections 1910.1018, 1910.1029 and 1910.1200
are also issued under 29 U.S.C. 653.
PART 1910—OCCUPATIONAL SAFETY AND HEALTH STANDARDS
(Continued)
Subpart Z—Toxic and Hazardous
Substances
Sec.
1910.1000 Air contaminants.
1910.1001 Asbestos.
1910.1002 Coal tar pitch volatiles; interpretation of term.
1910.1003 13 Carcinogens (4-Nitrobiphenyl,
etc.).
1910.1004 alpha-Naphthylamine.
1910.1005 [Reserved]
1910.1006 Methyl chloromethyl ether.
1910.1007 3,′—Dichlorobenzidine
(and
its
salts).
1910.1008 bis-Chloromethyl ether.
1910.1009 beta-Naphthylamine.
1910.1010 Benzidine.
1910.1011 4-Aminodiphenyl.
1910.1012 Ethyleneimine.
1910.1013 beta-Propiolactone.
1910.1014 2-Acetylaminofluorene.
1910.1015 4-Dimethylaminoazobenzene.
1910.1016 N-Nitrosodimethylamine.
1910.1017 Vinyl chloride.
1910.1018 Inorganic arsenic.
1910.1020 Access to employee exposure and
medical records.
1910.1025 Lead.
1910.1027 Cadmium.
1910.1028 Benzene.
1910.1029 Coke oven emissions.
1910.1030 Bloodborne pathogens.
1910.1043 Cotton dust.
1910.1044 1,2-dibromo-3-chloropropane.
1910.1045 Acrylonitrile.
1910.1047 Ethylene oxide.
1910.1048 Formaldehyde.
1910.1050 Methylenedianiline.
1910.1051 1,3–Butadiene.
1910.1052 Methylene Chloride.
1910.1096 Ionizing radiation.
1910.1200 Hazard communication.
1910.1201 Retention of DOT markings, placards and labels.
1910.1450 Occupational exposure to hazardous chemicals in laboratories.
SUBJECT INDEX FOR 29 CFR PART 1910—OCCUPATIONAL SAFETY AND HEALTH STAND-
SOURCE: 39 FR 23502, June 27, 1974, unless
otherwise noted. Redesignated at 40 FR 23072,
May 28, 1975.
§ 1910.1000 Air contaminants.
An employee’s exposure to any substance listed in Tables Z–1, Z–2, or Z–3
of this section shall be limited in accordance with the requirements of the
following paragraphs of this section.
(a) Table Z–1—(1) Substances with limits preceded by ‘‘C’’—Ceiling Values. An
employee’s exposure to any substance
in Table Z–1, the exposure limit of
which is preceded by a ‘‘C’’, shall at no
time exceed the exposure limit given
for that substance. If instantaneous
monitoring is not feasible, then the
ceiling shall be assessed as a 15-minute
time weighted average exposure which
shall not be exceeded at any time during the working day.
(2) Other substances—8-hour Time
Weighted Averages. An employee’s exposure to any substance in Table Z–1, the
exposure limit of which is not preceded
by a ‘‘C’’, shall not exceed the 8-hour
Time Weighted Average given for that
substance in any 8-hour work shift of a
40-hour work week.
(b) Table Z–2. An employee’s exposure
to any substance listed in Table Z–2
shall not exceed the exposure limits
specified as follows:
(1) 8-hour time weighted averages. An
employee’s exposure to any substance
listed in Table Z–2, in any 8-hour work
shift of a 40-hour work week, shall not
exceed the 8-hour time weighted average limit given for that substance in
Table Z–2.
ARDS
Subpart Z—Toxic and Hazardous
Substances
AUTHORITY: Sections 4, 6, and 8 of the Occupational Safety and Health Act of 1970 (29
U.S.C. 653, 655, 657); Secretary of Labor’s
Order No. 12–71 (36 FR 8754), 8–76 (41 FR
25059), 9–83 (48 FR 35736), or 6–96 (62 FR 111),
as applicable; and 29 CFR part 1911.
7
§ 1910.1000
29 CFR Ch. XVII (7–1–99 Edition)
(2) Acceptable ceiling concentrations.
An employee’s exposure to a substance
listed in Table Z–2 shall not exceed at
any time during an 8-hour shift the acceptable ceiling concentration limit
given for the substance in the table, except for a time period, and up to a concentration not exceeding the maximum
duration and concentration allowed in
the column under ‘‘acceptable maximum peak above the acceptable ceiling concentration for an 8-hour shift.’’
(3) Example. During an 8-hour work
shift, an employee may be exposed to a
concentration of Substance A (with a
10 ppm TWA, 25 ppm ceiling and 50 ppm
peak) above 25 ppm (but never above 50
ppm) only for a maximum period of 10
minutes. Such exposure must be compensated by exposures to concentrations less than 10 ppm so that the cumulative exposure for the entire 8-hour
work shift does not exceed a weighted
average of 10 ppm.
(c) Table Z–3. An employee’s exposure
to any substance listed in Table Z–3, in
any 8-hour work shift of a 40-hour work
week, shall not exceed the 8-hour time
weighted average limit given for that
substance in the table.
(d) Computation formulae. The computation formula which shall apply to
employee exposure to more than one
substance for which 8-hour time
weighted averages are listed in subpart
Z of 29 CFR part 1910 in order to determine whether an employee is exposed
over the regulatory limit is as follows:
(1)(i) The cumulative exposure for an
8-hour work shift shall be computed as
follows:
that an employee is subject to the following exposure:
Two hours exposure at 150 ppm
Two hours exposure at 75 ppm
Four hours exposure at 50 ppm
Substituting this information in the formula, we have
(2×150+2×75+4×50)÷8=81.25 ppm
Since 81.25 ppm is less than 100 ppm, the 8hour time weighted average limit, the exposure is acceptable.
(2)(i) In case of a mixture of air contaminants an employer shall compute
the equivalent exposure as follows:
Em=(C1÷L1+C2÷L2)+. . .(Cn÷Ln)
Where:
Em is the equivalent exposure for the mixture.
C is the concentration of a particular contaminant.
L is the exposure limit for that substance
specified in subpart Z of 29 CFR part 1910.
The value of Em shall not exceed unity (1).
(ii) To illustrate the formula prescribed in paragraph (d)(2)(i) of this
section, consider the following exposures:
Substance
B ................................................
C ................................................
D ................................................
Actual concentration of
8-hour exposure
(ppm)
8-hour TWA
PEL (ppm)
500
45
40
1,000
200
200
Substituting in the formula, we have:
Em=500÷1,000+45÷200+40÷200
Em=0.500+0.225+0.200
Em=0.925
Since Em is less than unity (1), the exposure
combination is within acceptable limits.
E = (Ca Ta+Cb Tb+. . .Cn Tn)÷8
Where:
E is the equivalent exposure for the working
shift.
C is the concentration during any period of
time T where the concentration remains
constant.
T is the duration in hours of the exposure at
the concentration C.
The value of E shall not exceed the 8-hour
time weighted average specified in subpart Z
of 29 CFR part 1910 for the substance involved.
(e) To achieve compliance with paragraphs (a) through (d) of this section,
administrative or engineering controls
must first be determined and implemented whenever feasible. When such
controls are not feasible to achieve full
compliance, protective equipment or
any other protective measures shall be
used to keep the exposure of employees
to air contaminants within the limits
prescribed in this section. Any equipment and/or technical measures used
for this purpose must be approved for
each particular use by a competent industrial hygienist or other technically
qualified person. Whenever respirators
(ii) To illustrate the formula prescribed in paragraph (d)(1)(i) of this
section, assume that Substance A has
an 8-hour time weighted average limit
of 100 ppm noted in Table Z–1. Assume
8
Occupational Safety and Health Admin., Labor
are used, their use shall comply with
1910.134.
(f) Effective dates. The exposure limits
specified have been in effect with the
§ 1910.1000
method of compliance specified in
paragraph (e) of this section since May
29, 1971.
TABLE Z–1—LIMITS FOR AIR CONTAMINANTS
Substance
Acetaldehyde ..........................................................................
Acetic acid ..............................................................................
Acetic anhydride .....................................................................
Acetone ..................................................................................
Acetonitrile ..............................................................................
2-Acetylaminofluorine; see 1910.1014 ...................................
Acetylene dichloride; see 1,2-Dichloroethylene.
Acetylene tetrabromide ..........................................................
Acrolein ...................................................................................
Acrylamide ..............................................................................
Acrylonitrile; see 1910.1045 ...................................................
Aldrin ......................................................................................
Allyl alcohol ............................................................................
Allyl chloride ...........................................................................
Allyl glycidyl ether (AGE) .......................................................
Allyl propyl disulfide ................................................................
alpha-Alumina .........................................................................
Total dust ........................................................................
Respirable fraction ..........................................................
Aluminum, metal (as Al) .........................................................
Total dust ........................................................................
4-Aminodiphenyl; see 1910.1011 ...........................................
2-Aminoethanol; see Ethanolamine.
2-Aminopyridine ......................................................................
Ammonia ................................................................................
Ammonium sulfamate .............................................................
Total dust ........................................................................
n-Amyl acetate .......................................................................
sec-Amyl acetate ....................................................................
Aniline and homologs .............................................................
Anisidine (o-, p-isomers) ........................................................
Antimony and compounds (as Sb) .........................................
ANTU (alpha Naphthylthiourea) .............................................
Arsenic, inorganic compounds (as As); see 1910.1018 ........
Arsenic, organic compounds (as As) .....................................
Arsine .....................................................................................
Asbestos; see 1910.1001 .......................................................
Azinphos-methyl .....................................................................
Barium, soluble compounds (as Ba) ......................................
Barium sulfate ........................................................................
Total dust ........................................................................
Benomyl ..................................................................................
Total dust ........................................................................
Benzene; see 1910.1028 .......................................................
ppm (a) 1
mg/m3 (b) 1
75–07–0
64–19–7
108–24–7
67–64–1
75–05–8
53–96–3
200
10
5
1000
40
360
25
20
2400
70
79–27–6
107–02–8
79–06–1
107–13–1
309–00–2
107–18–6
107–05–1
106–92–3
2179–59–1
1344–28–1
1
0.1
......................
14
0.25
0.3
......................
2
1
(C)10
2
0.25
5
3
(C)45
12
......................
......................
15
5
......................
......................
15
5
CAS No. (c)
Skin designation
X
X
X
7429–90–5
92–67–1
504–29–0
7664–41–7
7773–06–0
628–63–7
626–38–0
62–53–3
29191–52–4
7440–36–0
86–88–4
7440–38–2
7440–38–2
7784–42–1
(4)
86–50–0
7440–39–3
7727–43–7
0.5
50
2
35
......................
......................
100
125
5
......................
......................
......................
15
5
525
650
19
0.5
0.5
0.3
......................
0.05
0.5
0.2
......................
......................
0.2
0.5
......................
......................
15
5
......................
......................
15
5
......................
1
5
5
(2)
......................
......................
15
5
......................
(C)1
0.1
0.5
15
(C)3
0.7
5
X
X
X
17804–35–2
71–43–2
See Table Z–2 for the limits applicable in the operations or sectors excluded in 1910.1028 d
Benzidine; see 1910.1010 ......................................................
p-Benzoquinone; see Quinone.
Benzo(a)pyrene; see Coal tar pitch volatiles..
Benzoyl peroxide ....................................................................
Benzyl chloride .......................................................................
Beryllium and beryllium compounds (as Be) .........................
Biphenyl; see Diphenyl.
Bismuth telluride, Undoped ....................................................
Total dust ........................................................................
Boron oxide ............................................................................
Total dust ........................................................................
Boron trifluoride ......................................................................
Bromine ..................................................................................
Bromoform ..............................................................................
92–87–5
94–36–0
100–44–7
7440–41–7
1304–82–1
1303–86–2
7637–07–2
7726–95–6
75–25–2
9
X
§ 1910.1000
TABLE Z–1—LIMITS FOR AIR CONTAMINANTS—Continued
Substance
Butadiene (1,3-Butadiene); See 29 CFR 1910.1051; 29
CFR 1910.19(l).
Butanethiol; see Butyl mercaptan.
2-Butanone (Methyl ethyl ketone) ..........................................
2-Butoxyethanol ......................................................................
n-Butyl-acetate .......................................................................
sec-Butyl acetate ....................................................................
tert-Butyl acetate ....................................................................
n-Butyl alcohol ........................................................................
sec-Butyl alcohol ....................................................................
tert-Butyl alcohol .....................................................................
Butylamine ..............................................................................
tert-Butyl chromate (as CrO3) ................................................
n-Butyl glycidyl ether (BGE) ...................................................
Butyl mercaptan .....................................................................
p-tert-Butyltoluene ..................................................................
Cadmium (as Cd); see 1910.1027 .........................................
Calcium carbonate .................................................................
Total dust ........................................................................
Calcium hydroxide ..................................................................
Total dust ........................................................................
Calcium oxide .........................................................................
Calcium silicate ......................................................................
Total dust ........................................................................
Calcium sulfate .......................................................................
Total dust ........................................................................
Camphor, synthetic ................................................................
Carbaryl (Sevin) .....................................................................
Carbon black ..........................................................................
Carbon dioxide .......................................................................
Carbon disulfide .....................................................................
Carbon monoxide ...................................................................
Carbon tetrachloride ...............................................................
Cellulose .................................................................................
Total dust ........................................................................
Chlordane ...............................................................................
Chlorinated camphene ...........................................................
Chlorinated diphenyl oxide .....................................................
Chlorine ..................................................................................
Chlorine dioxide ......................................................................
Chlorine trifluoride ..................................................................
Chloroacetaldehyde ................................................................
a-Chloroacetophenone (Phenacyl chloride) ...........................
Chlorobenzene .......................................................................
o-Chlorobenzylidene malononitrile .........................................
Chlorobromomethane .............................................................
2-Chloro-1,3-butadiene; see beta-Chloroprene.
Chlorodiphenyl (42% Chlorine) (PCB) ...................................
Chlorodiphenyl (54% Chlorine) (PCB) ...................................
1-Chloro-2,3-epoxypropane; see Epichlorohydrin.
2-Chloroethanol; see Ethylene chlorohydrin.
Chloroethylene; see Vinyl chloride.
Chloroform (Trichloromethane) ..............................................
bis(Chloromethyl) ether; see 1910.1008 ................................
Chloromethyl methyl ether; see 1910.1006 ...........................
1-Chloro-1-nitropropane .........................................................
Chloropicrin ............................................................................
beta-Chloroprene ....................................................................
2-Chloro-6-(trichloromethyl) pyridine ......................................
Total dust ........................................................................
Chromic acid and chromates (as CrO3) .................................
Chromium (II) compounds.
(as Cr) .............................................................................
Chromium (III) compounds.
(as Cr) .............................................................................
Chromium metal and insol. salts (as Cr) ...............................
CAS No. (c)
106–99–0
78–93–3
111–76–2
123–86–4
105–46–4
540–88–5
71–36–3
78–92–2
75–65–0
109–73–9
1189–85–1
2426–08–6
109–79–5
98–51–1
7440–43–9
1317–65–3
ppm (a) 1
1 ppm/5
ppm STEL
mg/m3 (b) 1
Skin designation
....................
200
50
150
200
200
100
150
100
(C)5
......................
50
10
10
590
240
710
950
950
300
450
300
(C)15
(C)0.1
270
35
60
......................
......................
15
5
......................
......................
......................
15
5
5
......................
......................
15
5
......................
......................
......................
......................
......................
5000
15
5
2
5
3.5
9000
(2)
55
(2)
X
X
X
1305–62–0
1305–78–8
1344–95–2
7778–18–9
76–22–2
63–25–2
1333–86–4
124–38–9
75–15–0
630–08–0
56–23–5
9004–34–6
50
57–74–9
8001–35–2
55720–99–5
7782–50–5
10049–04–4
7790–91–2
107–20–0
532–27–4
108–90–7
2698–41–1
74–97–5
......................
......................
......................
......................
......................
(C)1
0.1
(C)0.1
(C)1
0.05
75
0.05
200
15
5
0.5
0.5
0.5
(C)3
0.3
(C)0.4
(C)3
0.3
350
0.4
1050
53469–21–9
11097–69–1
......................
......................
1
0.5
67–66–3
542–88–1
107–30–2
600–25–9
76–06–2
126–99–8
1929–82–4
(C)50
20
0.1
25
......................
......................
(4)
10
X
X
X
X
(C)240
100
0.7
90
15
5
(2)
7440–47–3
......................
0.5
7440–47–3
7440–47–3
......................
......................
0.5
1
X
§ 1910.1000
Substance
Chrysene; see Coal tar pitch volatiles.
Clopidol ...................................................................................
Total dust ........................................................................
Coal dust (less than 5% SiO2), respirable fraction ................
Coal dust (greater than or equal to 5% SiO2), respirable
fraction.
Coal tar pitch volatiles (benzene soluble fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene.
Cobalt metal, dust, and fume (as Co) ....................................
Coke oven emissions; see 1910.1029.
Copper ....................................................................................
Fume (as Cu) ..................................................................
Dusts and mists (as Cu) .................................................
Cotton dust e; see 1910.1043 .................................................
Crag herbicide (Sesone) ........................................................
Total dust ........................................................................
Cresol, all isomers ..................................................................
Crotonaldehyde ......................................................................
Cumene ..................................................................................
Cyanides (as CN) ...................................................................
Cyclohexane ...........................................................................
Cyclohexanol ..........................................................................
Cyclohexanone .......................................................................
Cyclohexene ...........................................................................
Cyclopentadiene .....................................................................
2,4-D (Dichlorophenoxyacetic acid) .......................................
Decaborane ............................................................................
Demeton (Systox) ...................................................................
Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone) ...........
1,2-Diaminoethane; see Ethylenediamine.
Diazomethane ........................................................................
Diborane .................................................................................
1,2-Dibromo-3-chloropropane (DBCP); see 1910.1044 ........
1,2-Dibromoethane; see Ethylene dibromide.
Dibutyl phosphate ...................................................................
Dibutyl phthalate .....................................................................
o-Dichlorobenzene .................................................................
p-Dichlorobenzene .................................................................
3,′-Dichlorobenzidine; see 1910.1007 ....................................
Dichlorodifluoromethane .........................................................
1,3-Dichloro-5,5-dimethyl hydantoin .......................................
Dichlorodiphenyltrichloroethane (DDT) ..................................
1,1-Dichloroethane .................................................................
1,2-Dichloroethane; see Ethylene dichloride.
1,2-Dichloroethylene ...............................................................
Dichloroethyl ether .................................................................
Dichloromethane; see Methylene chloride.
Dichloromonofluoromethane ..................................................
1,1-Dichloro-1-nitroethane ......................................................
1,2-Dichloropropane; see Propylene dichloride.
Dichlorotetrafluoroethane .......................................................
Dichlorvos (DDVP) .................................................................
Dicyclopentadienyl iron ..........................................................
Total dust ........................................................................
Dieldrin ...................................................................................
Diethylamine ...........................................................................
2-Diethylaminoethanol ............................................................
Diethyl ether; see Ethyl ether.
Difluorodibromomethane ........................................................
Diglycidyl ether (DGE) ............................................................
Dihydroxybenzene; see Hydroquinone.
Diisobutyl ketone ....................................................................
Diisopropylamine ....................................................................
4-Dimethylaminoazobenzene; see 1910.1015 .......................
Dimethoxymethane; see Methylal.
Dimethyl acetamide ................................................................
Dimethylamine ........................................................................
Dimethylaminobenzene; see Xylidine.
CAS No. (c)
ppm (a) 1
mg/m3 (b) 1
Skin designation
2971–90–6
......................
......................
15
5
(3)
(3)
65966–93–2
......................
0.2
7440–48–4
......................
0.1
......................
......................
......................
0.1
1
1
7440–50–8
136–78–7
1319–77–3
123–73–9;
4170–30–3
98–82–8
(4)
110–82–7
108–93–0
108–94–1
110–83–8
542–92–7
94–75–7
17702–41–9
8065–48–3
123–42–2
334–88–3
19287–45–7
96–12–8
15
5
22
6
50
......................
300
50
50
300
75
......................
0.05
......................
50
245
5
1050
200
200
1015
200
10
0.3
0.1
240
0.2
0.1
1
......................
(C)50
75
540–59–0
111–44–4
200
(C)15
790
(C)90
75–43–4
594–72–9
1000
(C)10
4200
(C)60
76–14–2
62–73–7
102–54–5
1000
......................
7000
1
1000
......................
......................
100
......................
......................
......................
25
10
X
X
X
X
X
0.4
0.1
107–66–4
84–74–2
95–50–1
106–46–7
91–94–1
75–71–8
118–52–5
50–29–3
75–34–3
60–57–1
109–89–7
100–37–8
11
......................
......................
5
2
5
5
(C)300
450
4950
0.2
1
400
15
5
0.25
75
50
75–61–6
2238–07–5
100
(C)0.5
860
(C)2.8
108–83–8
108–18–9
60–11–7
50
5
290
20
127–19–5
124–40–3
10
10
35
18
X
X
X
X
X
X
X
§ 1910.1000
Substance
Dimethylaniline (N,N-Dimethylaniline) ....................................
Dimethylbenzene; see Xylene.
Dimethyl-1,2-dibromo-2,2-dichloroethyl phosphate ................
Dimethylformamide .................................................................
2,6-Dimethyl-4-heptanone; see Diisobutyl ketone.
1,1-Dimethylhydrazine ............................................................
Dimethylphthalate ...................................................................
Dimethyl sulfate ......................................................................
Dinitrobenzene (all isomers) ..................................................
(ortho) ..............................................................................
(meta) ..............................................................................
(para) ...............................................................................
Dinitro-o-cresol .......................................................................
Dinitrotoluene .........................................................................
Dioxane (Diethylene dioxide) .................................................
Diphenyl (Biphenyl) ................................................................
Diphenylmethane diisocyanate; see Methylene bisphenyl
isocyanate.
Dipropylene glycol methyl ether .............................................
Di-sec octyl phthalate (Di-(2-ethylhexyl) phthalate) ...............
Emery .....................................................................................
Total dust ........................................................................
Endrin .....................................................................................
Epichlorohydrin .......................................................................
EPN ........................................................................................
1,2-Epoxypropane; see Propylene oxide.
2,3-Epoxy-1-propanol; see Glycidol.
Ethanethiol; see Ethyl mercaptan.
Ethanolamine ..........................................................................
2-Ethoxyethanol (Cellosolve) .................................................
2-Ethoxyethyl acetate (Cellosolve acetate) ............................
Ethyl acetate ...........................................................................
Ethyl acrylate ..........................................................................
Ethyl alcohol (Ethanol) ...........................................................
Ethylamine ..............................................................................
Ethyl amyl ketone (5-Methyl-3-heptanone) ............................
Ethyl benzene .........................................................................
Ethyl bromide .........................................................................
Ethyl butyl ketone (3-Heptanone) ..........................................
Ethyl chloride ..........................................................................
Ethyl ether ..............................................................................
Ethyl formate ..........................................................................
Ethyl mercaptan .....................................................................
Ethyl silicate ...........................................................................
Ethylene chlorohydrin .............................................................
Ethylenediamine .....................................................................
Ethylene dibromide .................................................................
Ethylene dichloride (1,2-Dichloroethane) ...............................
Ethylene glycol dinitrate .........................................................
Ethylene glycol methyl acetate; see Methyl cellosolve acetate.
Ethyleneimine; see 1910.1012 ...............................................
Ethylene oxide; see 1910.1047 ..............................................
Ethylidene chloride; see 1,1-Dichloroethane.
N-Ethylmorpholine ..................................................................
Ferbam ...................................................................................
Total dust ........................................................................
Ferrovanadium dust ...............................................................
Fluorides (as F) ......................................................................
Fluorine ...................................................................................
Fluorotrichloromethane (Trichlorofluoromethane) ..................
Formaldehyde; see 1910.1048 ..............................................
Formic acid .............................................................................
Furfural ...................................................................................
Furfuryl alcohol .......................................................................
Grain dust (oat, wheat, barley) ..............................................
Glycerin (mist) ........................................................................
Total dust ........................................................................
Glycidol ...................................................................................
Glycol monoethyl ether; see 2-Ethoxyethanol.
CAS No. (c)
121–69–7
ppm (a) 1
5
mg/m3 (b) 1
Skin designation
25
X
300–76–5
68–12–2
......................
10
3
30
X
57–14–7
131–11–3
77–78–1
0.5
......................
1
1
5
5
1
X
X
528–29–0
99–65–0
100–25–4
534–52–1
25321–14–6
123–91–1
92–52–4
......................
......................
100
0.2
0.2
1.5
360
1
X
X
X
100
......................
600
5
X
34590–94–8
117–81–7
12415–34–8
72–20–8
106–89–8
2104–64–5
141–43–5
110–80–5
111–15–9
141–78–6
140–88–5
64–17–5
75–04–7
541–85–5
100–41–4
74–96–4
106–35–4
75–00–3
60–29–7
109–94–4
75–08–1
78–10–4
107–07–3
107–15–3
106–93–4
107–06–2
628–96–6
......................
......................
......................
5
......................
3
200
100
400
25
1000
10
25
100
200
50
1000
400
100
(C)10
100
5
10
(C)0.2
15
5
0.1
19
0.5
6
740
540
1400
100
1900
18
130
435
890
230
2600
1200
300
(C)25
850
16
25
(2)
(2)
(C)1
X
X
X
X
X
X
X
X
X
151–56–4
75–21–8
100–74–3
14484–64–1
12604–58–9
(4)
7782–41–4
75–69–4
50–00–0
64–18–6
98–01–1
98–00–0
........................
56–81–5
556–52–5
12
20
94
......................
......................
......................
0.1
1000
15
1
2.5
0.2
5600
5
5
50
......................
9
20
200
10
......................
......................
50
15
5
150
X
X
§ 1910.1000
Substance
Graphite, natural, respirable dust ...........................................
Graphite, synthetic .................................................................
Total dust ........................................................................
Guthion; see Azinphos methyl.
Gypsum ..................................................................................
Total dust ........................................................................
Hafnium ..................................................................................
Heptachlor ..............................................................................
Heptane (n-Heptane) ..............................................................
Hexachloroethane ..................................................................
Hexachloronaphthalene ..........................................................
n-Hexane ................................................................................
2-Hexanone (Methyl n-butyl ketone) ......................................
Hexone (Methyl isobutyl ketone) ............................................
sec-Hexyl acetate ...................................................................
Hydrazine ...............................................................................
Hydrogen bromide ..................................................................
Hydrogen chloride ..................................................................
Hydrogen cyanide ..................................................................
Hydrogen fluoride (as F) ........................................................
Hydrogen peroxide .................................................................
Hydrogen selenide (as Se) ....................................................
Hydrogen sulfide ....................................................................
Hydroquinone .........................................................................
Iodine ......................................................................................
Iron oxide fume ......................................................................
Isoamyl acetate ......................................................................
Isoamyl alcohol (primary and secondary) ..............................
Isobutyl acetate ......................................................................
Isobutyl alcohol .......................................................................
Isophorone ..............................................................................
Isopropyl acetate ....................................................................
Isopropyl alcohol ....................................................................
Isopropylamine .......................................................................
Isopropyl ether ........................................................................
Isopropyl glycidyl ether (IGE) .................................................
Kaolin ......................................................................................
Total dust ........................................................................
Ketene ....................................................................................
Lead, inorganic (as Pb); see 1910.1025 ................................
Limestone ...............................................................................
Total dust ........................................................................
Lindane ...................................................................................
Lithium hydride .......................................................................
L.P.G. (Liquefied petroleum gas) ...........................................
Magnesite ...............................................................................
Total dust ........................................................................
Magnesium oxide fume ..........................................................
Total particulate ...............................................................
Malathion ................................................................................
Total dust ........................................................................
Maleic anhydride ....................................................................
Manganese compounds (as Mn) ...........................................
Manganese fume (as Mn) ......................................................
Marble .....................................................................................
Total dust ........................................................................
Mercury (aryl and inorganic) (as Hg) .....................................
Mercury (organo) alkyl compounds (as Hg) ..........................
Mercury (vapor) (as Hg) .........................................................
Mesityl oxide ...........................................................................
Methanethiol; see Methyl mercaptan.
Methoxychlor ..........................................................................
Total dust ........................................................................
2-Methoxyethanol (Methyl cellosolve) ....................................
2-Methoxyethyl acetate (Methyl cellosolve acetate) ..............
Methyl acetate ........................................................................
CAS No. (c)
ppm (a) 1
mg/m3 (b) 1
Skin designation
(3)
7782–42–5
......................
......................
15
5
......................
......................
......................
......................
500
1
......................
500
100
100
50
1
3
(C)5
10
......................
(C)0.1
......................
100
100
150
100
25
250
400
5
500
50
15
5
0.5
0.5
2000
10
0.2
1800
410
410
300
1.3
10
(C)7
11
(2)
1.4
0.2
2
( )
2
(C)1
10
525
360
700
300
140
950
980
12
2100
240
......................
......................
0.5
15
5
0.9
......................
......................
......................
......................
1000
15
5
0.5
0.025
1800
13397–24–5
7440–58–6
76–44–8
142–82–5
67–72–1
1335–87–1
110–54–3
591–78–6
108–10–1
108–84–9
302–01–2
10035–10–6
7647–01–0
74–90–8
7664–39–3
7722–84–1
7783–07–5
7783–06–4
123–31–9
7553–56–2
1309–37–1
123–92–2
123–51–3
110–19–0
78–83–1
78–59–1
108–21–4
67–63–0
75–31–0
108–20–3
4016–14–2
1332–58–7
463–51–4
7439–92–1
1317–65–3
58–89–9
7580–67–8
68476–85–7
546–93–0
1
0.05
......................
......................
15
5
......................
15
......................
0.25
......................
......................
15
1
(C)5
(C)5
......................
......................
15
5
(2)
(2)
(2)
100
X
X
X
X
X
X
1309–48–4
121–75–5
108–31–6
7439–96–5
7439–96–5
1317–65–3
7439–97–6
7439–97–6
7439–97–6
141–79–7
25
X
72–43–5
109–86–4
110–49–6
79–20–9
13
......................
25
25
200
15
80
120
610
X
X
§ 1910.1000
Substance
Methyl acetylene (Propyne) ...................................................
Methyl acetylene-propadiene mixture (MAPP) .......................
Methyl acrylate .......................................................................
Methylal (Dimethoxy-methane) ..............................................
Methyl alcohol ........................................................................
Methylamine ...........................................................................
Methyl amyl alcohol; see Methyl isobutyl carbinol.
Methyl n-amyl ketone .............................................................
Methyl bromide .......................................................................
Methyl butyl ketone; see 2-Hexanone.
Methyl cellosolve; see 2-Methoxyethanol.
Methyl cellosolve acetate; see 2-Methoxyethyl acetate.
Methyl chloride .......................................................................
Methyl chloroform (1,1,1-Trichloroethane) .............................
Methylcyclohexane .................................................................
Methylcyclohexanol ................................................................
o-Methylcyclohexanone ..........................................................
Methylene chloride .................................................................
Methyl ethyl ketone (MEK); see 2-Butanone.
Methyl formate ........................................................................
Methyl hydrazine (Monomethyl hydrazine) ............................
Methyl iodide ..........................................................................
Methyl isoamyl ketone ............................................................
Methyl isobutyl carbinol ..........................................................
Methyl isobutyl ketone; see Hexone.
Methyl isocyanate ...................................................................
Methyl mercaptan ...................................................................
Methyl methacrylate ...............................................................
Methyl propyl ketone; see 2-Pentanone.
alpha-Methyl styrene ..............................................................
Methylene bisphenyl isocyanate (MDI) ..................................
Mica; see Silicates.
Molybdenum (as Mo) .............................................................
Soluble compounds .........................................................
Insoluble compounds.
Total dust .................................................................
Monomethyl aniline ................................................................
Monomethyl hydrazine; see Methyl hydrazine.
Morpholine ..............................................................................
Naphtha (Coal tar) ..................................................................
Naphthalene ...........................................................................
alpha-Naphthylamine; see 1910.1004 ...................................
beta-Naphthylamine; see 1910.1009 .....................................
Nickel carbonyl (as Ni) ...........................................................
Nickel, metal and insoluble compounds (as Ni) ....................
Nickel, soluble compounds (as Ni) ........................................
Nicotine ...................................................................................
Nitric acid ................................................................................
Nitric oxide ..............................................................................
p-Nitroaniline ..........................................................................
Nitrobenzene ..........................................................................
p-Nitrochlorobenzene .............................................................
4-Nitrodiphenyl; see 1910.1003 .............................................
Nitroethane .............................................................................
Nitrogen dioxide .....................................................................
Nitrogen trifluoride ..................................................................
Nitroglycerin ............................................................................
Nitromethane ..........................................................................
1-Nitropropane ........................................................................
2-Nitropropane ........................................................................
N-Nitrosodimethylamine; see 1910.1016.
Nitrotoluene (all isomers) .......................................................
o-isomer ..........................................................................
m-isomer .........................................................................
p-isomer ..........................................................................
Nitrotrichloromethane; see Chloropicrin.
Octachloronaphthalene ..........................................................
Octane ....................................................................................
Oil mist, mineral .....................................................................
Osmium tetroxide (as Os) ......................................................
Oxalic acid ..............................................................................
Oxygen difluoride ...................................................................
ppm (a) 1
mg/m3 (b) 1
96–33–3
109–87–5
67–56–1
74–89–5
1000
1000
10
1000
200
10
1650
1800
35
3100
260
12
110–43–0
74–83–9
100
(C)20
465
(C)80
74–87–3
71–55–6
108–87–2
25639–42–3
583–60–8
75–09–2
350
500
100
100
(2)
1900
2000
470
460
(2)
107–31–3
60–34–4
74–88–4
110–12–3
108–11–2
100
(C)0.2
5
100
25
250
(C)0.35
28
475
100
624–83–9
74–93–1
80–62–6
0.02
(C)10
100
0.05
(C)20
410
98–83–9
101–68–8
(C)100
(C)0.02
CAS No. (c)
74–99–7
Skin designation
X
X
X
X
X
X
X
(C)480
(C)0.2
7439–98–7
100–61–8
110–91–8
8030–30–6
91–20–3
134–32–7
91–59–8
13463–39–3
7440–02–0
7440–02–0
54–11–5
7697–37–2
10102–43–9
100–01–6
98–95–3
100–00–5
92–93–3
79–24–3
10102–44–0
7783–54–2
55–63–0
75–52–5
108–03–2
79–46–9
......................
5
......................
2
15
9
20
100
10
70
400
50
0.001
......................
......................
......................
2
25
1
1
......................
100
(C)5
10
(C)0.2
100
25
25
5
0.007
1
1
0.5
5
30
6
5
1
X
X
X
X
X
X
310
(C)9
29
(C)2
250
90
90
X
30
X
88–72–2
99–08–1
99–99–0
2234–13–1
111–65–9
8012–95–1
20816–12–0
144–62–7
7783–41–7
14
......................
500
......................
......................
......................
0.05
0.1
2350
5
0.002
1
0.1
X
§ 1910.1000
Substance
Ozone .....................................................................................
Paraquat, respirable dust .......................................................
Parathion ................................................................................
Particulates not otherwise regulated (PNOR) f.
Total dust ........................................................................
PCB; see Chlorodiphenyl (42% and 54% chlorine).
Pentaborane ...........................................................................
Pentachloronaphthalene .........................................................
Pentachlorophenol ..................................................................
Pentaerythritol ........................................................................
Total dust ........................................................................
Pentane ..................................................................................
2-Pentanone (Methyl propyl ketone) ......................................
Perchloroethylene (Tetrachloroethylene) ...............................
Perchloromethyl mercaptan ...................................................
Perchloryl fluoride ...................................................................
Petroleum distillates (Naphtha) (Rubber Solvent) .................
Phenol ....................................................................................
p-Phenylene diamine ..............................................................
Phenyl ether, vapor ................................................................
Phenyl ether-biphenyl mixture, vapor ....................................
Phenylethylene; see Styrene.
Phenyl glycidyl ether (PGE) ...................................................
Phenylhydrazine .....................................................................
Phosdrin (Mevinphos) ............................................................
Phosgene (Carbonyl chloride) ................................................
Phosphine ...............................................................................
Phosphoric acid ......................................................................
Phosphorus (yellow) ...............................................................
Phosphorus pentachloride ......................................................
Phosphorus pentasulfide ........................................................
Phosphorus trichloride ............................................................
Phthalic anhydride ..................................................................
Picloram ..................................................................................
Total dust ........................................................................
Picric acid ...............................................................................
Pindone (2-Pivalyl-1,3-indandione) ........................................
Plaster of Paris .......................................................................
Total dust ........................................................................
Platinum (as Pt) ......................................................................
Metal ................................................................................
Soluble salts ....................................................................
Portland cement .....................................................................
Total dust ........................................................................
Propane ..................................................................................
beta-Propriolactone; see 1910.1013 ......................................
n-Propyl acetate .....................................................................
n-Propyl alcohol ......................................................................
n-Propyl nitrate .......................................................................
Propylene dichloride ...............................................................
Propylene imine ......................................................................
Propylene oxide ......................................................................
Propyne; see Methyl acetylene.
Pyrethrum ...............................................................................
Pyridine ...................................................................................
Quinone ..................................................................................
RDX; see Cyclonite.
Rhodium (as Rh), metal fume and insoluble compounds .....
Rhodium (as Rh), soluble compounds ...................................
Ronnel ....................................................................................
Rotenone ................................................................................
Rouge .....................................................................................
Total dust ........................................................................
Selenium compounds (as Se) ................................................
CAS No. (c)
10028–15–6
4685–14–7;
1910–42–5;
2074–50–2
56–38–2
ppm (a) 1
109–66–0
107–87–9
127–18–4
594–42–3
7616–94–6
108–95–2
106–50–3
101–84–8
122–60–1
100–63–0
7786–34–7
75–44–5
7803–51–2
7664–38–2
7723–14–0
10026–13–8
1314–80–3
7719–12–2
85–44–9
1918–02–1
88–89–1
83–26–1
26499–65–0
Skin designation
0.2
0.5
X
......................
0.1
X
......................
......................
19624–22–7
1321–64–8
87–86–5
115–77–5
mg/m3 (b) 1
0.1
......................
0.005
......................
......................
......................
......................
1000
200
15
5
0.01
0.5
0.5
0.1
3
500
5
......................
1
1
15
5
2950
700
(2)
0.8
13.5
2000
19
0.1
7
7
10
5
......................
0.1
0.3
......................
......................
......................
......................
0.5
2
60
22
0.1
0.4
0.4
1
0.1
1
1
3
12
......................
......................
......................
......................
15
5
0.1
0.1
......................
......................
15
5
......................
......................
....................
0.002
......................
1000
15
5
1800
200
200
25
75
2
100
840
500
110
350
5
240
X
X
X
X
X
X
X
7440–06–4
65997–15–1
74–98–6
57–57–8
109–60–4
71–23–8
627–13–4
78–87–5
75–55–8
75–56–9
15
8003–34–7
110–86–1
106–51–4
......................
5
0.1
5
15
0.4
7440–16–6
7440–16–6
299–84–3
83–79–4
......................
......................
......................
......................
0.1
0.001
15
5
7782–49–2
......................
......................
......................
15
5
0.2
X
§ 1910.1000
Substance
Selenium hexafluoride (as Se) ...............................................
Silica, amorphous, precipitated and gel .................................
Silica, amorphous, diatomaceous earth, containing less than
1% crystalline silica.
Silica, crystalline cristobalite, respirable dust ........................
Silica, crystalline quartz, respirable dust ................................
Silica, crystalline tripoli (as quartz), respirable dust ..............
Silica, crystalline tridymite, respirable dust ............................
Silica, fused, respirable dust ..................................................
Silicates (less than 1% crystalline silica) ...............................
Mica (respirable dust) .....................................................
Soapstone, total dust ......................................................
Soapstone, respirable dust .............................................
Talc (containing asbestos); use asbestos limit; see 29
CFR 1910.1001.
Talc (containing no asbestos), respirable dust ...............
Tremolite, asbestiform; see 1910.1001.
Silicon .....................................................................................
Total dust ........................................................................
Silicon carbide ........................................................................
Total dust ........................................................................
Silver, metal and soluble compounds (as Ag) .......................
Soapstone; see Silicates.
Sodium fluoroacetate .............................................................
Sodium hydroxide ...................................................................
Starch .....................................................................................
Total dust ........................................................................
Stibine .....................................................................................
Stoddard solvent ....................................................................
Strychnine ...............................................................................
Styrene ...................................................................................
Sucrose ..................................................................................
Total dust ........................................................................
Sulfur dioxide ..........................................................................
Sulfur hexafluoride .................................................................
Sulfuric acid ............................................................................
Sulfur monochloride ...............................................................
Sulfur pentafluoride ................................................................
Sulfuryl fluoride .......................................................................
Systox; see Demeton.
2,4,5-T (2,4,5-trichlorophenoxyacetic acid) ............................
Talc; see Silicates.
Tantalum, metal and oxide dust .............................................
TEDP (Sulfotep) .....................................................................
Tellurium and compounds (as Te) .........................................
Tellurium hexafluoride (as Te) ...............................................
Temephos ...............................................................................
Total dust ........................................................................
TEPP (Tetraethyl pyrophosphate) ..........................................
Terphenyls ..............................................................................
1,1,1,2-Tetrachloro-2,2-difluoroethane ...................................
1,1,2,2-Tetrachloro-1,2-difluoroethane ...................................
1,1,2,2-Tetrachloroethane ......................................................
Tetrachloroethylene; see Perchloroethylene.
Tetrachloromethane; see Carbon tetrachloride.
Tetrachloronaphthalene ..........................................................
Tetraethyl lead (as Pb) ...........................................................
Tetrahydrofuran ......................................................................
Tetramethyl lead (as Pb) ........................................................
Tetramethyl succinonitrile .......................................................
Tetranitromethane ..................................................................
Tetryl (2,4,6-Trinitrophenylmethylnitramine) ...........................
Thallium, soluble compounds (as Tl) .....................................
4,4′-Thiobis (6-tert, Butyl-m-cresol) ........................................
Total dust ........................................................................
Thiram ....................................................................................
CAS No. (c)
7783–79–1
112926–00–8
61790–53–2
ppm (a) 1
0.05
mg/m3 (b) 1
Skin designation
0.4
(3)
3
( )
14464–46–1
14808–60–7
1317–95–9
15468–32–3
60676–86–0
(3)
(3)
(3)
(3)
(3)
12001–26–2
........................
........................
........................
(3)
(3)
(3)
(3)
14807–96–6
(3)
7440–21–3
......................
......................
15
5
......................
......................
......................
15
5
0.01
......................
......................
0.05
2
......................
......................
0.1
500
......................
15
5
0.5
2900
0.15
(2)
7446–09–5
2551–62–4
7664–93–9
10025–67–9
5714–22–7
2699–79–8
......................
......................
5
1000
......................
1
0.025
5
15
5
13
6000
1
6
0.25
20
93–76–5
......................
10
7440–25–7
3689–24–5
13494–80–9
7783–80–4
3383–96–8
......................
......................
......................
0.02
409–21–2
7440–22–4
62–74–8
1310–73–2
9005–25–8
7803–52–3
8052–41–3
57–24–9
100–42–5
57–50–1
107–49–3
26140–60–3
76–11–9
76–12–0
79–34–5
1335–88–2
78–00–2
109–99–9
75–74–1
3333–52–6
509–14–8
479–45–8
7440–28–0
96–69–5
137–26–8
16
......................
......................
......................
(C)1
500
500
5
......................
......................
200
......................
0.5
1
......................
......................
......................
......................
......................
5
0.2
0.1
0.2
15
5
0.05
(C)9
4170
4170
35
2
0.075
590
0.075
3
8
1.5
0.1
15
5
5
X
X
X
X
X
X
X
X
X
X
§ 1910.1000
Substance
Tin, inorganic compounds (except oxides) (as Sn) ...............
Tin, organic compounds (as Sn) ............................................
Titanium dioxide .....................................................................
Total dust ........................................................................
Toluene ...................................................................................
Toluene-2,4-diisocyanate (TDI) ..............................................
o-Toluidine ..............................................................................
Toxaphene; see Chlorinated camphene.
Tremolite; see Silicates.
Tributyl phosphate ..................................................................
1,1,1-Trichloroethane; see Methyl chloroform.
1,1,2-Trichloroethane .............................................................
Trichloroethylene ....................................................................
Trichloromethane; see Chloroform.
Trichloronaphthalene ..............................................................
1,2,3-Trichloropropane ...........................................................
1,1,2-Trichloro-1,2,2-trifluoroethane .......................................
Triethylamine ..........................................................................
Trifluorobromomethane ..........................................................
2,4,6-Trinitrophenol; see Picric acid.
2,4,6-Trinitrophenylmethylnitramine; see Tetryl.
2,4,6-Trinitrotoluene (TNT) .....................................................
Triorthocresyl phosphate ........................................................
Triphenyl phosphate ...............................................................
Turpentine ..............................................................................
Uranium (as U) .......................................................................
Soluble compounds .........................................................
Insoluble compounds ......................................................
Vanadium ...............................................................................
Respirable dust (as V2 O5) .............................................
Fume (as V2 O5) .............................................................
Vegetable oil mist ...................................................................
Total dust ........................................................................
Vinyl benzene; see Styrene.
Vinyl chloride; see 1910.1017 ................................................
Vinyl cyanide; see Acrylonitrile.
Vinyl toluene ...........................................................................
Warfarin ..................................................................................
Xylenes (o-, m-, p-isomers) ....................................................
Xylidine ...................................................................................
Yttrium ....................................................................................
Zinc chloride fume ..................................................................
Zinc oxide fume ......................................................................
Zinc oxide ...............................................................................
Total dust ........................................................................
Zinc stearate ...........................................................................
Total dust ........................................................................
Zirconium compounds (as Zr) ................................................
CAS No. (c)
7440–31–5
7440–31–5
13463–67–7
ppm (a) 1
......................
......................
......................
108–88–3
584–84–9
95–53–4
126–73–8
79–00–5
79–01–6
(C)0.02
5
......................
10
1321–65–9
96–18–4
76–13–1
121–44–8
75–63–8
......................
50
1000
25
1000
118–96–7
78–30–8
115–86–6
8006–64–2
7440–61–1
......................
......................
......................
100
......................
......................
mg/m3 (b) 1
Skin designation
2
0.1
15
(2)
(C)0.14
22
X
5
45
(2)
X
5
300
7600
100
6100
X
1.5
0.1
3
560
X
0.05
0.25
1314–62–1
......................
......................
(C)0.5
(C)0.1
......................
......................
15
5
100
......................
100
5
......................
......................
......................
480
0.1
435
25
1
1
5
......................
......................
15
5
......................
......................
......................
15
5
5
75–01–4
25013–15–4
81–81–2
1330–20–7
1300–73–8
7440–65–5
7646–85–7
1314–13–2
1314–13–2
X
557–05–1
7440–67–7
1 The
PELs are 8-hour TWAs unless otherwise noted; a (C) designation denotes a ceiling limit. They are to be determined
from breathing-zone air samples.
(a) Parts of vapor or gas per million parts of contaminated air by volume at 25 ° C and 760 torr.
(b) Milligrams of substance per cubic meter of air. When entry is in this column only, the value is exact; when listed with a ppm
entry, it is approximate.
(c) The CAS number is for information only. Enforcement is based on the substance name. For an entry covering more than
one metal compound, measured as the metal, the CAS number for the metal is given—not CAS numbers for the individual compounds.
(d) The final benzene standard in 1910.1028 applies to all occupational exposures to benzene except in some circumstances
the distribution and sale of fuels, sealed containers and pipelines, coke production, oil and gas drilling and production, natural
gas processing, and the percentage exclusion for liquid mixtures; for the excepted subsegments, the benzene limits in Table Z–2
apply. See 1910.1028 for specific circumstances.
(e) This 8-hour TWA applies to respirable dust as measured by a vertical elutriator cotton dust sampler or equivalent instrument. The time-weighted average applies to the cottom waste processing operations of waste recycling (sorting, blending, cleaning and willowing) and garnetting. See also 1910.1043 for cotton dust limits applicable to other sectors.
(f) All inert or nuisance dusts, whether mineral, inorganic, or organic, not listed specifically by substance name are covered by
the Particulates Not Otherwise Regulated (PNOR) limit which is the same as the inert or nuisance dust limit of Table Z–3.
2 See Table Z–2.
3 See Table Z–3.
4 Varies with compound.
17
§ 1910.1000
TABLE Z–2
8-hour time
weighted average
Substance
Acceptable
ceiling concentration
Acceptable maximum peak
above the acceptable ceiling concentration for an 8-hr shift
Maximum duration
Concentration
Benzenea (Z37.40–1969) ....................................................
Beryllium and beryllium compounds (Z37.29–1970) ..........
Cadmium fumeb (Z37.5–1970) ............................................
Cadmium dustb (Z37.5–1970) .............................................
Carbon disulfide (Z37.3–1968) ...........................................
Carbon tetrachloride (Z37.17–1967) ...................................
10 ppm .........
2 µg/m3 .........
0.1 mg/m3 .....
0.2 mg/m3 .....
20 ppm .........
10 ppm .........
25 ppm .........
5 µg/m3 .........
0.3 mg/m3 .....
0.6 mg/m3.
30 ppm .........
25 ppm .........
50 ppm .........
25 µg/m3 .......
.......................
10 minutes.
30 minutes.
100 ppm .......
200 ppm .......
30 minutes.
5 min. in any 4
hrs.
Chromic acid and chromates (Z37.7–1971) .......................
Ethylene dibromide (Z37.31–1970) .....................................
Ethylene dichloride (Z37.21–1969) .....................................
.......................
20 ppm .........
50 ppm .........
1 mg/10m3.
30 ppm .........
100 ppm .......
50 ppm .........
200 ppm .......
5 minutes.
5 min. in any 3
hrs.
Fluoride as dust (Z37.28–1969) ..........................................
Formaldehyde; see 1910.1048 ...........................................
Hydrogen fluoride (Z37.28–1969) .......................................
Hydrogen sulfide (Z37.2–1966) ..........................................
2.5 mg/m3 .....
.......................
3 ppm ...........
.......................
.......................
.......................
.......................
20 ppm .........
.......................
.......................
.......................
50 ppm .........
Mercury (Z37.8–1971) .........................................................
Methyl chloride (Z37.18–1969) ...........................................
.......................
100 ppm .......
1 mg/10m3 ....
200 ppm .......
.......................
300 ppm .......
Methylene Chloride: See § 1919.52..
Organo (alkyl) mercury (Z37.30–1969) ...............................
Styrene (Z37.15–1969) .......................................................
0.01 mg/m3 ...
100 ppm .......
0.04 mg/m3 ...
200 ppm .......
.......................
600 ppm .......
Tetrachloroethylene (Z37.22–1967) ....................................
100 ppm .......
200 ppm .......
300 ppm .......
Toluene (Z37.12–1967) .......................................................
Trichloroethylene (Z37.19–1967) ........................................
200 ppm .......
100 ppm .......
300 ppm .......
200 ppm .......
500 ppm .......
300 ppm .......
10 mins. once,
only if no other
meas. exp. occurs.
5 mins. in any 3
hrs.
5 mins. in any 3
hrs.
5 mins. in any 3
hrs.
10 minutes.
5 mins. in any 2
hrs.
a This standard applies to the industry segments exempt from the 1 ppm 8-hour TWA and 5 ppm STEL of the benzene standard at 1910.1028.
b This standard applies to any operations or sectors for which the Cadmium standard, 1910.1027, is stayed or otherwise not in
effect.
TABLE Z–3—MINERAL DUSTS
mppcf a
mg/m3
Quartz (Respirable) .................................................................................................................
250 b
—————
%SiO2+5
10 mg/m3 e
—————
% SiO2 + 2
Quartz (Total Dust) .................................................................................................................
....................
30 mg/m3
—————
% SiO2 + 2
20
80 mg/m3
—————
%SiO2
Substance
Silica:
Crystalline
Cristobalite: Use 1⁄2 the value calculated from the count or mass formulae for quartz
Tridymite: Use 1⁄2 the value calculated from the formulae for quartz
Amorphous, including natural diatomaceous earth ...............................................................................
Silicates (less than 1% crystalline silica):
Mica ................................................................................................................................................
Soapstone ......................................................................................................................................
Talc (not containing asbestos) .......................................................................................................
Talc (containing asbestos) Use asbestos limit.
Tremolite, asbestiform (see 29 CFR 1910.1001).
Portland cement .............................................................................................................................
Graphite (Natural) ..................................................................................................................................
20
20
20 c
50
15
Coal Dust:
Respirable fraction less than 5% SiO2 ..........................................................................................
18
....................
2.4 mg/m3 e
§ 1910.1001
TABLE Z–3—MINERAL DUSTS—Continued
mppcf a
mg/m3
Respirable fraction greater than 5% SiO2 .....................................................................................
....................
10 mg/m3 e
—————
%SiO2+2
Inert or Nuisance Dust: d
Respirable fraction .........................................................................................................................
Total dust .......................................................................................................................................
15
50
Substance
5 mg/m3
15 mg/m3
Note—Conversion factors - mppcf X 35.3 = million particles per cubic meter = particles per c.c.
a Millions of particles per cubic foot of air, based on impinger samples counted by light-field techniques.
b The percentage of crystalline silica in the formula is the amount determined from airborne samples, except in those instances
in which other methods have been shown to be applicable.
c Containing less than 1% quartz; if 1% quartz or more, use quartz limit.
d All inert or nuisance dusts, whether mineral, inorganic, or organic, not listed specifically by substance name are covered by
this limit, which is the same as the Particulates Not Otherwise Regulated (PNOR) limit in Table Z–1.
e Both concentration and percent quartz for the application of this limit are to be determined from the fraction passing a sizeselector with the following characteristics:
Aerodynamic diameter (unit density sphere)
2 ...........................................................................................................................................................................
2.5 ........................................................................................................................................................................
3.5 ........................................................................................................................................................................
5.0 ........................................................................................................................................................................
10 .........................................................................................................................................................................
Percent passing
selector
90
75
50
25
0
The measurements under this note refer to the use of an AEC (now NRC) instrument. The respirable fraction of coal dust is
determined with an MRE; the figure corresponding to that of 2.4 mg/m3 in the table for coal dust is 4.5 mg/m3K.
[58 FR 35340, June 30. 1993; 58 FR 40191, July 27, 1993, as amended at 61 FR 56831, Nov. 4, 1996;
62 FR 1600, Jan. 10, 1997; 62 FR 42018, Aug. 4, 1997]
Assistant Secretary means the Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or designee.
Authorized person means any person
authorized by the employer and required by work duties to be present in
regulated areas.
Building/facility owner is the legal entity, including a lessee, which exercises
control over management and record
keeping functions relating to a building and/or facility in which activities
covered by this standard take place.
Certified industrial hygienist (CIH)
means one certified in the practice of
industrial hygiene by the American
Board of Industrial Hygiene.
Director means the Director of the
National Institute for Occupational
Safety and Health, U.S. Department of
Health and Human Services, or designee.
Employee exposure means that exposure to airborne asbestos that would
occur if the employee were not using
respiratory protective equipment.
Fiber means a particulate form of asbestos 5 micrometers or longer,with a
§ 1910.1001 Asbestos.
(a) Scope and application. (1) This section applies to all occupational exposures to asbestos in all industries covered by the Occupational Safety and
Health Act, except as provided in paragraph (a)(2) and (3) of this section.
(2) This section does not apply to
construction work as defined in 29 CFR
1910.12(b). (Exposure to asbestos in construction work is covered by 29 CFR
1926.1101).
(3) This section does not apply to
ship
repairing,
shipbuilding
and
shipbreaking employments and related
employments as defined in 29 CFR
1915.4. (Exposure to asbestos in these
employments is covered by 29 CFR
1915.1001).
(b) Definitions.
Asbestos includes chrysotile, amosite,
crocidolite,
tremolite
asbestos,
anthophyllite asbestos, actinolite asbestos, and any of these minerals that
have been chemically treated and/or altered.
Asbestos-containing material (ACM)
means any material containing more
than 1% asbestos.
19
§ 1910.1001
length-to-diameter ratio of at least 3 to
1.
High-efficiency particulate air (HEPA)
filter means a filter capable of trapping
and retaining at least 99.97 percent of
0.3 micrometer diameter mono-disperse
particles.
Homogeneous area means an area of
surfacing material or thermal system
insulation that is uniform in color and
texture.
Industrial hygienist means a professional qualified by education, training,
and experience to anticipate, recognize, evaluate and develop controls for
occupational health hazards.
PACM means ‘‘presumed asbestos
containing material.’’
Presumed asbestos containing material
means thermal system insulation and
surfacing material found in buildings
constructed no later than 1980. The designation of a material as ‘‘PACM’’ may
be rebutted pursuant to paragraph
(j)(8) of this section.
Regulated area means an area established by the employer to demarcate
areas where airborne concentrations of
asbestos exceed, or there is a reasonable possibility they may exceed, the
permissible exposure limits.
Surfacing ACM means surfacing material which contains more than 1% asbestos.
Surfacing material means material
that is sprayed, troweled-on or otherwise applied to surfaces (such as acoustical plaster on ceilings and fireproofing materials on structural members, or other materials on surfaces for
acoustical, fireproofing, and other purposes).
Thermal System Insulation (TSI) means
ACM applied to pipes, fittings, boilers,
breeching, tanks, ducts or other structural components to prevent heat loss
or gain.
Thermal System Insulation ACM means
thermal system insulation which contains more than 1% asbestos.
(c) Permissible exposure limit (PELS)—
(1) Time-weighted average limit (TWA).
The employer shall ensure that no employee is exposed to an airborne concentration of asbestos in excess of 0.1
fiber per cubic centimeter of air as an
eight (8)-hour time-weighted average
(TWA) as determined by the method
prescribed in Appendix A to this section, or by an equivalent method.
(2) Excursion limit. The employer shall
ensure that no employee is exposed to
an airborne concentration of asbestos
in excess of 1.0 fiber per cubic centimeter of air (1 f/cc) as averaged over a
sampling period of thirty (30) minutes
as determined by the method prescribed in Appendix A to this section,
or by an equivalent method.
(d) Exposure monitoring—(1) General.
(i) Determinations of employee exposure shall be made from breathing zone
air samples that are representative of
the 8-hour TWA and 30-minute shortterm exposures of each employee.
(ii) Representative 8-hour TWA employee exposures shall be determined
on the basis of one or more samples
representing full-shift exposures for
each shift for each employee in each
job classification in each work area.
Representative 30-minute short-term
employee exposures shall be determined on the basis of one or more samples representing 30 minute exposures
associated with operations that are
most likely to produce exposures above
the excursion limit for each shift for
each job classification in each work
area.
(2) Initial monitoring. (i) Each employer who has a workplace or work
operation covered by this standard, except as provided for in paragraphs
(d)(2)(ii) and (d)(2)(iii) of this section,
shall perform initial monitoring of employees who are, or may reasonably be
expected to be exposed to airborne concentrations at or above the TWA permissible exposure limit and/or excursion limit.
(ii) Where the employer has monitored after March 31, 1992, for the TWA
permissible exposure limit and/or the
excursion limit, and the monitoring
satisfies all other requirements of this
section, the employer may rely on such
earlier monitoring results to satisfy
the requirements of paragraph (d)(2)(i)
of this section.
(iii) Where the employer has relied
upon objective data that demonstrate
that asbestos is not capable of being released in airborne concentrations at or
above the TWA permissible exposure
limit and/or excursion limit under the
expected conditions of processing, use,
20
or handling, then no initial monitoring
is required.
(3) Monitoring frequency (periodic monitoring) and patterns. After the initial
determinations required by paragraph
(d)(2)(i) of this section, samples shall
be of such frequency and pattern as to
represent with reasonable accuracy the
levels of exposure of the employees. In
no case shall sampling be at intervals
greater than six months for employees
whose exposures may reasonably be
foreseen to exceed the TWA permissible exposure limit and/or excursion
limit.
(4) Changes in monitoring frequency. If
either the initial or the periodic monitoring required by paragraphs (d)(2)
and (d)(3) of this section statistically
indicates that employee exposures are
below the TWA permissible exposure
limit and/or excursion limit, the employer may discontinue the monitoring
for those employees whose exposures
are represented by such monitoring.
(5) Additional monitoring. Notwithstanding the provisions of paragraphs
(d)(2)(ii) and (d)(4) of this section, the
employer shall institute the exposure
monitoring required under paragraphs
(d)(2)(i) and (d)(3) of this section whenever there has been a change in the
production, process, control equipment, personnel or work practices that
may result in new or additional exposures above the TWA permissible exposure limit and/or excursion limit or
when the employer has any reason to
suspect that a change may result in
new or additional exposures above the
PEL and/or excursion limit.
(6) Method of monitoring. (i) All samples taken to satisfy the monitoring requirements of paragraph (d) of this section shall be personal samples collected following the procedures specified in Appendix A.
(ii) All samples taken to satisfy the
monitoring requirements of paragraph
(d) of this section shall be evaluated
using the OSHA Reference Method
(ORM) specified in Appendix A of this
section, or an equivalent counting
method.
(iii) If an equivalent method to the
ORM is used, the employer shall ensure
that the method meets the following
criteria:
§ 1910.1001
(A) Replicate exposure data used to
establish equivalency are collected in
side-by-side field and laboratory comparisons; and
(B) The comparison indicates that
90% of the samples collected in the
range 0.5 to 2.0 times the permissible
limit have an accuracy range of plus or
minus 25 percent of the ORM results at
a 95% confidence level as demonstrated
by a statistically valid protocol; and
(C) The equivalent method is documented and the results of the comparison testing are maintained.
(iv) To satisfy the monitoring requirements of paragraph (d) of this section, employers must use the results of
monitoring analysis performed by laboratories which have instituted quality
assurance programs that include the
elements as prescribed in Appendix A
of this section.
(7) Employee notification of monitoring
results. (i) The employer shall, within
15 working days after the receipt of the
results of any monitoring performed
under the standard, notify the affected
employees of these results in writing
either individually or by posting of results in an appropriate location that is
accessible to affected employees.
(ii) The written notification required
by paragraph (d)(7)(i) of this section
shall contain the corrective action
being taken by the employer to reduce
employee exposure to or below the
TWA and/or excursion limit, wherever
monitoring results indicated that the
TWA and/or excursion limit had been
exceeded.
(e) Regulated Areas—(1) Establishment.
The employer shall establish regulated
areas wherever airborne concentrations
of asbestos and/or PACM are in excess
of the TWA and/or excursion limit prescribed in paragraph (c) of this section.
(2) Demarcation. Regulated areas shall
be demarcated from the rest of the
workplace in any manner that minimizes the number of persons who will
be exposed to asbestos.
(3) Access. Access to regulated areas
shall be limited to authorized persons
or to persons authorized by the Act or
regulations issued pursuant thereto.
(4) Provision of respirators. Each person entering a regulated area shall be
21
§ 1910.1001
(iv) Local exhaust ventilation. Local
exhaust ventilation and dust collection
systems shall be designed, constructed,
installed, and maintained in accordance with good practices such as those
found in the American National Standard Fundamentals Governing the Design and Operation of Local Exhaust
Systems, ANSI Z9.2–1979.
(v) Particular tools. All hand-operated
and power-operated tools which would
produce or release fibers of asbestos,
such as, but not limited to, saws, scorers, abrasive wheels, and drills, shall be
provided with local exhaust ventilation
systems which comply with paragraph
(f)(1)(iv) of this section.
(vi) Wet methods. Insofar as practicable, asbestos shall be handled,
mixed, applied, removed, cut, scored,
or otherwise worked in a wet state sufficient to prevent the emission of airborne fibers so as to expose employees
to levels in excess of the TWA and/or
excursion limit, prescribed in paragraph (c) of this section, unless the
usefulness of the product would be diminished thereby.
(vii) [Reserved]
(viii) Particular products and operations. No asbestos cement, mortar,
coating, grout, plaster, or similar material containing asbestos, shall be removed from bags, cartons, or other
containers in which they are shipped,
without being either wetted, or enclosed, or ventilated so as to prevent
effectively the release of airborne fibers.
(ix) Compressed air. Compressed air
shall not be used to remove asbestos or
materials containing asbestos unless
the compressed air is used in conjunction with a ventilation system which
effectively captures the dust cloud created by the compressed air.
(x) Flooring. Sanding of asbestos-containing flooring material is prohibited.
(2) Compliance program. (i) Where the
TWA and/or excursion limit is exceeded, the employer shall establish and
implement a written program to reduce
TWA and to or below the excursion
limit by means of engineering and
work practice controls as required by
paragraph (f)(1) of this section, and by
the use of respiratory protection where
supplied with and required to use a respirator, selected in accordance with
paragraph (g)(2) of this section.
(5) Prohibited activities. The employer
shall ensure that employees do not eat,
drink, smoke, chew tobacco or gum, or
apply cosmetics in the regulated areas.
(f) Methods of compliance—(1) Engineering controls and work practices. (i)
The employer shall institute engineering controls and work practices to reduce and maintain employee exposure
to or below the TWA and/or excursion
limit prescribed in paragraph (c) of this
section, except to the extent that such
controls are not feasible.
(ii) Wherever the feasible engineering
controls and work practices that can
be instituted are not sufficient to reduce employee exposure to or below the
TWA and/or excursion limit prescribed
in paragraph (c) of this section, the employer shall use them to reduce employee exposure to the lowest levels
achievable by these controls and shall
supplement them by the use of respiratory protection that complies with
the requirements of paragraph (g) of
this section.
(iii) For the following operations,
wherever feasible engineering controls
and work practices that can be instituted are not sufficient to reduce the
TWA and/or excursion limit prescribed
in paragraph (c) of this section, the employer shall use them to reduce employee exposure to or below 0.5 fiber
per cubic centimeter of air (as an
eight-hour time-weighted average) or
2.5 fibers/cc for 30 minutes (short-term
exposure) and shall supplement them
by the use of any combination of respiratory protection that complies with
this section, work practices and feasible engineering controls that will reduce employee exposure to or below the
TWA and to or below the excursion
limit permissible prescribed in paragraph (c) of this section: Coupling cutoff in primary asbestos cement pipe
manufacturing; sanding in primary and
secondary asbestos cement sheet manufacturing; grinding in primary and
secondary friction product manufacturing; carding and spinning in dry textile processes; and grinding and sanding in primary plastics manufacturing.
22
required or permitted under this section.
(ii) Such programs shall be reviewed
and updated as necessary to reflect significant changes in the status of the
employer’s compliance program.
(iii) Written programs shall be submitted upon request for examination
and copying to the Assistant Secretary, the Director, affected employees and designated employee representatives.
(iv) The employer shall not use employee rotation as a means of compliance with the TWA and/or excursion
limit.
(3) Specific compliance methods for
brake and clutch repair:
(i) Engineering controls and work
practices for brake and clutch repair
and service. During automotive brake
and clutch inspection, disassembly, repair and assembly operations, the employer shall institute engineering controls and work practices to reduce employee exposure to materials containing asbestos using a negative pressure enclosure/HEPA vacuum system
method or low pressure/wet cleaning
method, which meets the detailed requirements set out in Appendix F to
this section. The employer may also
comply using an equivalent method
which follows written procedures which
the employer demonstrates can achieve
results equivalent to Method A in Appendix F to this section. For facilities
in which no more than 5 pair of brakes
or 5 clutches are inspected, disassembled, repaired, or assembled per week,
the method set forth in paragraph [D]
of Appendix F to this section may be
used.
(ii) The employer may also comply
by using an equivalent method which
follows written procedures, which the
employer demonstrates can achieve
equivalent exposure reductions as do
the two ‘‘preferred methods.’’ Such
demonstration must include monitoring data conducted under workplace
conditions closely resembling the process, type of asbestos containing materials, control method, work practices
and environmental conditions which
the equivalent method will be used, or
objective data, which document that
under all reasonably foreseeable conditions of brake and clutch repair appli-
§ 1910.1001
cations, the method results in exposures which are equivalent to the
methods set out in Appendix F to this
section.
(g) Respiratory protection—(1) General.
For employees who use respirators required by this section, the employer
must provide respirators that comply
with the requirements of this paragraph. Respirators must be used during:
(i) Periods necessary to install or implement feasible engineering and workpractice controls.
(ii) Work operations, such as maintenance and repair activities, for which
engineering and work-practice controls
are not feasible.
(iii) Work operations for which feasible engineering and work-practice
controls are not yet sufficient to reduce employee exposure to or below the
TWA and/or excursion limit.
(iv) Emergencies.
(2) Respirator program. (i) The employer must implement a respiratory
protection program in accordance with
29 CFR 1910.134 (b) through (d) (except
(d)(1)(iii)), and (f) through (m).
(ii) The employer must provide a
tight-fitting, powered, air-purifying
respirator instead of any negative-pressure respirator specified in Table 1 of
this section when an employee chooses
to use this type of respirator and the
respirator provides adequate protection
to the employee.
(iii) No employee must be assigned to
tasks requiring the use of respirators
if, based on their most recent medical
examination, the examining physician
determines that the employee will be
unable to function normally using a
respirator, or that the safety or health
of the employee or other employees
will be impaired by the use of a respirator. Such employees must be assigned to another job or given the opportunity to transfer to a different position, the duties of which they can
perform. If such a transfer position is
available, the position must be with
the same employer, in the same geographical area, and with the same seniority, status, and rate of pay the employee had just prior to such transfer.
23
§ 1910.1001
(3) Respirator selection. The employer
must select and provide the appro-
priate respirator from Table 1 of this
section.
TABLE 1—RESPIRATORY PROTECTION FOR ASBESTOS FIBERS
Airborne concentration of asbestos or conditions of use
Required respirator
Not in excess of 1 f/cc (10 X PEL) .............
Half-mask air purifying respirator other than a disposable respirator, equipped with
high efficiency filters.
Full facepiece air-purifying respirator equipped with high efficiency filters.
Any powered air-purifying respirator equipped with high efficiency filters or any
supplied air respirator operated in continuous flow mode.
Full facepiece supplied air respirator operated in pressure demand mode.
Full facepiece supplied air respirator operated in pressure demand mode, equipped
with an auxiliary positive pressure self-contained breathing apparatus.
Not in excess of 5 f/cc (50 X PEL) .............
Not in excess of 10 f/cc (100 X PEL) .........
Not in excess of 100 f/cc (1,000 X PEL) ....
Greater than 100 f/cc (1,000 X PEL) or unknown concentration.
NOTE: a. Respirators assigned for high environmental concentrations may be used at lower concentrations, or when required
respirator use is independent of concentration.
b. A high efficiency filter means a filter that is at least 99.97 percent efficient against mono-dispersed particles of 0.3 micrometers in diameter or larger.
(h) Protective work clothing and equipment—(1) Provision and use. If an employee is exposed to asbestos above the
TWA and/or excursion limit, or where
the possibility of eye irritation exists,
the employer shall provide at no cost
to the employee and ensure that the
employee uses appropriate protective
work clothing and equipment such as,
but not limited to:
(i) Coveralls or similar full-body
work clothing;
(ii) Gloves, head coverings, and foot
coverings; and
(iii) Face shields, vented goggles, or
other appropriate protective equipment which complies with 1910.133 of
this Part.
(2) Removal and storage. (i) The employer shall ensure that employees remove work clothing contaminated with
asbestos only in change rooms provided
in accordance with paragraph (i)(1) of
this section.
(ii) The employer shall ensure that
no employee takes contaminated work
clothing out of the change room, except those employees authorized to do
so for the purpose of laundering, maintenance, or disposal.
(iii) Contaminated work clothing
shall be placed and stored in closed
containers which prevent dispersion of
the asbestos outside the container.
(iv) Containers of contaminated protective devices or work clothing which
are to be taken out of change rooms or
the workplace for cleaning, maintenance or disposal, shall bear labels in
accordance with paragraph (j)(4) of this
section.
(3) Cleaning and replacement. (i) The
employer shall clean, launder, repair,
or replace protective clothing and
equipment required by this paragraph
to maintain their effectiveness. The
employer shall provide clean protective
clothing and equipment at least weekly
to each affected employee.
(ii) The employer shall prohibit the
removal of asbestos from protective
clothing and equipment by blowing or
shaking. (iii) Laundering of contaminated clothing shall be done so as to
prevent the release of airborne fibers of
asbestos in excess of the permissible
exposure limits prescribed in paragraph (c) of this section.
(iv) Any employer who gives contaminated clothing to another person
for laundering shall inform such person
of the requirement in paragraph
(h)(3)(iii) of this section to effectively
prevent the release of airborne fibers of
asbestos in excess of the permissible
exposure limits.
(v) The employer shall inform any
person who launders or cleans protective clothing or equipment contaminated with asbestos of the potentially
harmful effects of exposure to asbestos.
(vi) Contaminated clothing shall be
transported in sealed impermeable
bags, or other closed, impermeable containers, and labeled in accordance with
paragraph (j) of this section.
(i) Hygiene facilities and practices—(1)
Change rooms. (i) The employer shall
provide clean change rooms for employees who work in areas where their
airborne exposure to asbestos is above
the TWA and/or excursion limit.
24
change rooms are in accordance with
1910.141(e) of this part, and are
equipped with two separate lockers or
storage facilities, so separated as to
prevent contamination of the employee’s street clothes from his protective
work clothing and equipment.
(2) Showers. (i) The employer shall ensure that employees who work in areas
where their airborne exposure is above
the TWA and/or excursion limit, shower at the end of the work shift.
(ii) The employer shall provide shower facilities which comply with
1910.141(d)(3) of this part.
(iii) The employer shall ensure that
employees who are required to shower
pursuant to paragraph (i)(2)(i) of this
section do not leave the workplace
wearing any clothing or equipment
worn during the work shift.
(3) Lunchrooms. (i) The employer
shall provide lunchroom facilities for
employees who work in areas where
their airborne exposure is above the
TWA and/or excursion limit.
lunchroom facilities have a positive
pressure, filtered air supply, and are
readily accessible to employees.
their airborne exposure is above the
PEL and/or excursion limit wash their
hands and faces prior to eating, drinking or smoking.
(iv) The employer shall ensure that
employees do not enter lunchroom facilities with protective work clothing
or equipment unless surface asbestos
fibers have been removed from the
clothing or equipment by vacuuming or
other method that removes dust without causing the asbestos to become airborne.
(4) Smoking in work areas. The employer shall ensure that employees do
not smoke in work areas where they
are occupationally exposed to asbestos
because of activities in that work area.
(j) Communication of hazards to employees—Introduction. This section applies to the communication of information concerning asbestos hazards in
general industry to facilitate compliance with this standard. Asbestos exposure in general industry occurs in a
wide variety of industrial and commer-
§ 1910.1001
cial settings. Employees who manufacture asbestos-containing products may
be exposed to asbestos fibers. Employees who repair and replace automotive
brakes and clutches may be exposed to
asbestos fibers. In addition, employees
engaged in housekeeping activities in
industrial facilities with asbestos product manufacturing operations, and in
public and commercial buildings with
installed asbestos containing materials
may be exposed to asbestos fibers. Most
of these workers are covered by this
general industry standard, with the exception of state or local governmental
employees in non-state plan states. It
should be noted that employees who
perform housekeeping activities during
and after construction activities are
covered by the asbestos construction
standard, 29 CFR 1926.1101, formerly
1926.58. However, housekeeping employees, regardless of industry designation,
should know whether building components they maintain may expose them
to asbestos. The same hazard communication provisions will protect employees who perform housekeeping operations in all three asbestos standards; general industry, construction,
and shipyard employment. As noted in
the construction standard, building
owners are often the only and/or best
source of information concerning the
presence of previously installed asbestos containing building materials.
Therefore they, along with employers
of potentially exposed employees, are
assigned specific information conveying and retention duties under this
section.
(1) Installed Asbestos Containing Material. Employers and building owners are
required to treat installed TSI and
sprayed on and troweled-on surfacing
materials as ACM in buildings constructed no later than 1980 for purposes
of this standard. These materials are
designated ‘‘presumed ACM or PACM’’,
and are defined in paragraph (b) of this
section. Asphalt and vinyl flooring material installed no later than 1980 also
must be treated as asbestos-containing.
The employer or building owner may
demonstrate that PACM and flooring
material do not contain asbestos by
complying with paragraph (j)(8)(iii) of
this section.
25
§ 1910.1001
(2) Duties of employers and building
and facility owners. (i) Building and facility owners shall determine the presence, location, and quantity of ACM
and/or PACM at the work site. Employers and building and facility owners
shall exercise due diligence in complying with these requirements to inform employers and employees about
the presence and location of ACM and
PACM.
(ii) Building and facility owners shall
maintain records of all information required to be provided pursuant to this
section and/or otherwise known to the
building owner concerning the presence, location and quantity of ACM
and PACM in the building/facility.
Such records shall be kept for the duration of ownership and shall be transferred to successive owners.
(iii) Building and facility owners
shall inform employers of employees,
and employers shall inform employees
who will perform housekeeping activities in areas which contain ACM and/or
PACM of the presence and location of
ACM and/or PACM in such areas which
may be contacted during such activities.
(3) Warning signs—(i) Posting. Warning signs shall be provided and displayed at each regulated area. In addition, warning signs shall be posted at
all approaches to regulated areas so
that an employee may read the signs
and take necessary protective steps before entering the area.
(ii) Sign specifications. (A) The warning signs required by paragraph (j)(3) of
this section shall bear the following information:
(iv) The employer shall ensure that
employees working in and contiguous
to regulated areas comprehend the
warning signs required to be posted by
paragraph (j)(3)(i) of this section.
Means to ensure employee comprehension may include the use of foreign languages, pictographs and graphics.
(v) At the entrance to mechanical
rooms/areas in which employees reasonably can be expected to enter and
which contain ACM and/or PACM, the
building owner shall post signs which
identify the material which is present,
its location, and appropriate work
practices which, if followed, will ensure
that ACM and/or PACM will not be disturbed. The employer shall ensure, to
the extent feasible, that employees
who come in contact with these signs
can comprehend them. Means to ensure
employee comprehension may include
the use of foreign languages, pictographs, graphics, and awareness training.
(4) Warning labels—(i) Labeling. Warning labels shall be affixed to all raw
materials, mixtures, scrap, waste, debris, and other products containing asbestos fibers, or to their containers.When a building owner or employer identifies previously installed
ACM and/or PACM, labels or signs shall
be affixed or posted so that employees
will be notified of what materials contain ACM and/or PACM. The employer
shall attach such labels in areas where
they will clearly be noticed by employees who are likely to be exposed, such
as at the entrance to mechanical room/
areas. Signs required by paragraph
(j)(3) of this section may be posted in
lieu of labels so long as they contain
information required for labelling.
(ii) Label specifications. The labels
shall comply with the requirements of
29 CFR 1910.1200(f) of OSHA’s Hazard
Communication standard, and shall include the following information:
DANGER
ASBESTOS
CANCER AND LUNG DISEASE HAZARD
AUTHORIZED PERSONNEL ONLY
(B) In addition, where the use of respirators and protective clothing is required in the regulated area under this
section, the warning signs shall include
the following:
DANGER
CONTAINS ASBESTOS FIBERS
AVOID CREATING DUST
RESPIRATORS AND PROTECTIVE
CLOTHING
CANCER AND LUNG DISEASE HAZARD
ARE REQUIRED IN THIS AREA
(5) Material safety data sheets. Employers who are manufacturers or importers of asbestos or asbestos products
(iii) [Reserved]
26
shall comply with the requirements regarding development of material safety
data sheets as specified in 29 CFR
1910.1200(g) of OSHA’s Hazard Communication standard, except as provided
by paragraph (j)(6) of this section.
(6) The provisions for labels required
by paragraph (j)(4) of this section or for
material safety data sheets required by
paragraph (j)(5) of this section do not
apply where:
(i) Asbestos fibers have been modified
by a bonding agent, coating, binder, or
other material provided that the manufacturer can demonstrate that during
any reasonably foreseeable use, handling, storage, disposal, processing, or
transportation, no airborne concentrations of fibers of asbestos in excess of
the TWA permissible exposure level
and/or excursion limit will be released
or
(ii) Asbestos is present in a product
in concentrations less than 1.0%.
(7) Employee information and training.
(i) The employer shall institute a
training program for all employees who
are exposed to airborne concentrations
of asbestos at or above the PEL and/or
excursion limit and ensure their participation in the program.
(ii) Training shall be provided prior
to or at the time of initial assignment
and at least annually thereafter.
(iii) The training program shall be
conducted in a manner which the employee is able to understand. The employer shall ensure that each employee
is informed of the following:
(A) The health effects associated
with asbestos exposure;
(B) The relationship between smoking and exposure to asbestos producing
lung cancer:
(C) The quantity, location, manner of
use, release, and storage of asbestos,
and the specific nature of operations
which could result in exposure to asbestos;
(D) The engineering controls and
work practices associated with the employee’s job assignment;
(E) The specific procedures implemented to protect employees from exposure to asbestos, such as appropriate
work practices, emergency and cleanup procedures, and personal protective
equipment to be used;
§ 1910.1001
(F) The purpose, proper use, and limitations of respirators and protective
clothing, if appropriate;
(G) The purpose and a description of
the medical surveillance program required by paragraph (l) of this section;
(H) The content of this standard, including appendices.
(I) The names, addresses and phone
numbers of public health organizations
which provide information, materials,
and/or conduct programs concerning
smoking cessation. The employer may
distribute the list of such organizations contained in Appendix I to this
section, to comply with this requirement.
(J) The requirements for posting
signs and affixing labels and the meaning of the required legends for such
signs and labels.
(iv) The employer shall also provide,
at no cost to employees who perform
housekeeping operations in an area
which contains ACM or PACM, an asbestos awareness training course,
which shall at a minimum contain the
following elements: health effects of
asbestos, locations of ACM and PACM
in the building/facility, recognition of
ACM and PACM damage and deterioration, requirements in this standard relating to housekeeping, and proper response to fiber release episodes, to all
employees who perform housekeeping
work in areas where ACM and/or PACM
is present. Each such employee shall be
so trained at least once a year.
(v) Access to information and training materials.
(A) The employer shall make a copy
of this standard and its appendices
readily available without cost to all affected employees.
(B) The employer shall provide, upon
request, all materials relating to the
employee information and training
program to the Assistant Secretary
and the training program to the Assistant Secretary and the Director.
(C) The employer shall inform all employees concerning the availability of
self-help smoking cessation program
material. Upon employee request, the
employer shall distribute such material, consisting of NIH Publication No.
89–1647, or equivalent self-help material, which is approved or published by
27
§ 1910.1001
a public health organization listed in
Appendix I to this section.
(8) Criteria to rebut the designation of
installed material as PACM. (i) At any
time, an employer and/or building
owner may demonstrate, for purposes
of this standard, that PACM does not
contain asbestos. Building owners and/
or employers are not required to communicate information about the presence of building material for which
such a demonstration pursuant to the
requirements of paragraph (j)(8)(ii) of
this section has been made. However,
in all such cases, the information, data
and analysis supporting the determination that PACM does not contain asbestos, shall be retained pursuant to
paragraph (m) of this section.
(ii) An employer or owner may demonstrate that PACM does not contain
asbestos by the following:
(A) Having a completed inspection
conducted pursuant to the requirements of AHERA (40 CFR 763, Subpart
E) which demonstrates that no ACM is
present in the material; or
(B) Performing tests of the material
containing PACM which demonstrate
that no ACM is present in the material.
Such tests shall include analysis of
bulk samples collected in the manner
described in 40 CFR 763.86. The tests,
evaluation and sample collection shall
be conducted by an accredited inspector or by a CIH. Analysis of samples
shall be performed by persons or laboratories
with
proficiency
demonstrated by current successful participation in a nationally recognized testing program such as the National Voluntary Laboratory Accreditation Program (NVLAP) or the National Institute for Standards and Technology
(NIST) or the Round Robin for bulk
samples administered by the American
Industrial Hygiene Association (AIHA)
or an equivalent nationally-recognized
round robin testing program.
(iii) The employer and/or building
owner may demonstrate that flooring
material including associated mastic
and backing does not contain asbestos,
by a determination of an industrial hygienist based upon recognized analytical techniques showing that the material is not ACM.
(k) Housekeeping. (1) All surfaces
shall be maintained as free as prac-
ticable of ACM waste and debris and
accompanying dust.
(2) All spills and sudden releases of
material containing asbestos shall be
cleaned up as soon as possible.
(3) Surfaces contaminated with asbestos may not be cleaned by the use of
compressed air.
(4)
Vacuuming.
HEPA-filtered
vacuuming equipment shall be used for
vacuuming asbestos containing waste
and debris. The equipment shall be
used and emptied in a manner which
minimizes the reentry of asbestos into
the workplace.
(5) Shoveling, dry sweeping and dry
clean-up of asbestos may be used only
where vacuuming and/or wet cleaning
are not feasible.
(6) Waste disposal. Waste, scrap, debris, bags, containers, equipment, and
clothing contaminated with asbestos
consigned for disposal, shall be collected, recycled and disposed of in
sealed impermeable bags, or other
closed, impermeable containers.
(7) Care of asbestos-containing flooring material.
(i) Sanding of asbestos-containing
floor material is prohibited.
(ii) Stripping of finishes shall be conducted using low abrasion pads at
speeds lower than 300 rpm and wet
methods.
(iii) Burnishing or dry buffing may be
performed only on asbestos-containing
flooring which has sufficient finish so
that the pad cannot contact the asbestos-containing material.
(8) Waste and debris and accompanying dust in an area containing accessible ACM and/or PACM or visibly
deteriorated ACM, shall not be dusted
or swept dry, or vacuumed without
using a HEPA filter.
(l) Medical surveillance—(1) General—
(i) Employees covered. The employer
shall institute a medical surveillance
program for all employees who are or
will be exposed to airborne concentrations of fibers of asbestos at or above
the TWA and/or excursion limit.
(ii) Examination by a physician. (A)
The employer shall ensure that all
medical examinations and procedures
are performed by or under the supervision of a licensed physician, and shall
28
be provided without cost to the employee and at a reasonable time and
place.
(B) Persons other than licensed physicians, who administer the pulmonary
function testing required by this section, shall complete a training course
in spirometry sponsored by an appropriate academic or professional institution.
(2) Pre-placement examinations. (i) Before an employee is assigned to an occupation exposed to airborne concentrations of asbestos fibers at or
above the TWA and/or excursion limit,
a pre-placement medical examination
shall be provided or made available by
the employer.
(ii) Such examination shall include,
as a minimum, a medical and work history; a complete physical examination
of all systems with emphasis on the
respiratory system, the cardiovascular
system and digestive tract; completion
of the respiratory disease standardized
§ 1910.1001
questionnaire in Appendix D to this
section, Part 1; a chest roentgenogram
(posterior-anterior 14×17 inches); pulmonary function tests to include forced
vital capacity (FVC) and forced expiratory volume at 1 second (FEV(1.0)); and
any additional tests deemed appropriate by the examining physician. Interpretation and classification of chest
roentgenogram shall be conducted in
accordance with Appendix E to this
section.
(3) Periodic examinations. (i) Periodic
medical examinations shall be made
available annually.
(ii) The scope of the medical examination shall be in conformance with
the protocol established in paragraph
(l)(2)(ii) of this section, except that the
frequency of chest roentgenogram shall
be conducted in accordance with Table
2, and the abbreviated standardized
questionnaire contained in, Part 2 of
Appendix D to this section shall be administered to the employee.
TABLE 2—FREQUENCY OF CHEST ROENTGENOGRAM
Age of employee
Years since first exposure
0 to 10 .............................................................
10+ ..................................................................
15 to 35
35+ to 45
Every 5 years ...................
Every 5 years ...................
Every 5 years ...................
Every 2 years ...................
(4) Termination of employment examinations. (i) The employer shall provide,
or make available, a termination of
employment medical examination for
any employee who has been exposed to
airborne concentrations of fibers of asbestos at or above the TWA and/or excursion limit.
(ii) The medical examination shall be
in accordance with the requirements of
the periodic examinations stipulated in
paragraph (l)(3) of this section, and
shall be given within 30 calendar days
before or after the date of termination
of employment.
(5) Recent examinations. No medical
examination is required of any employee, if adequate records show that
the employee has been examined in accordance with any of paragraphs ((l)(2)
through (l)(4)) of this section within
the past 1 year period. A pre- employment medical examination which was
required as a condition of employment
by the employer, may not be used by
45+
Every 5 years.
Every 1 year.
that employer to meet the requirements of this paragraph, unless the
cost of such examination is borne by
the employer.
(6) Information provided to the physician. The employer shall provide the
following information to the examining physician:
(i) A copy of this standard and Appendices D and E.
(ii) A description of the affected employee’s duties as they relate to the
employee’s exposure.
(iii) The employee’s representative
exposure level or anticipated exposure
level.
(iv) A description of any personal
protective and respiratory equipment
used or to be used.
(v) Information from previous medical examinations of the affected employee that is not otherwise available
to the examining physician.
(7) Physician’s written opinion. (i) The
employer shall obtain a written signed
29
§ 1910.1001
opinion from the examining physician.
This written opinion shall contain the
results of the medical examination and
shall include:
(A) The physician’s opinion as to
whether the employee has any detected
medical conditions that would place
the employee at an increased risk of
material health impairment from exposure to asbestos;
(B) Any recommended limitations on
the employee or upon the use of personal protective equipment such as
clothing or respirators;
(C) A statement that the employee
has been informed by the physician of
the results of the medical examination
and of any medical conditions resulting
from asbestos exposure that require
further explanation or treatment; and
(D) A statement that the employee
the increased risk of lung cancer attributable to the combined effect of
smoking and asbestos exposure.
(ii) The employer shall instruct the
physician not to reveal in the written
opinion given to the employer specific
findings or diagnoses unrelated to occupational exposure to asbestos.
(iii) The employer shall provide a
copy of the physician’s written opinion
to the affected employee within 30 days
from its receipt.
(m) Recordkeeping—(1) Exposure measurements.
(F) Name, social security number and
exposure of the employees whose exposure are represented.
(iii) The employer shall maintain
this record for at least thirty (30)
years, in accordance with 29 CFR
1910.20.
(2) Objective data for exempted operations. (i) Where the processing, use, or
handling of products made from or containing asbestos is exempted from
other requirements of this section
under paragraph (d)(2)(iii) of this section, the employer shall establish and
maintain an accurate record of objective data reasonably relied upon in support of the exemption.
(ii) The record shall include at least
the following:
(A) The product qualifying for exemption;
(B) The source of the objective data;
(C) The testing protocol, results of
testing, and/or analysis of the material
for the release of asbestos;
(D) A description of the operation exempted and how the data support the
exemption; and
(E) Other data relevant to the operations, materials, processing, or employee exposures covered by the exemption.
this record for the duration of the employer’s reliance upon such objective
data.
(3) Medical surveillance. (i) The employer shall establish and maintain an
accurate record for each employee subject to medical surveillance by paragraph (l)(1)(i) of this section, in accordance with 29 CFR 1910.20.
the following information:
(A) The name and social security
number of the employee;
(B) Physician’s written opinions;
(C) Any employee medical complaints related to exposure to asbestos;
and
(D) A copy of the information provided to the physician as required by
paragraph (l)(6) of this section.
this record is maintained for the duration of employment plus thirty (30)
1910.20.
NOTE: The employer may utilize the services of competent organizations such as industry trade associations and employee associations to maintain the records required by
this section.
(i) The employer shall keep an accurate record of all measurements taken
to monitor employee exposure to asbestos as prescribed in paragraph (d) of
this section.
(ii) This record shall include at least
(A) The date of measurement;
(B) The operation involving exposure
to asbestos which is being monitored;
(C) Sampling and analytical methods
used and evidence of their accuracy;
(D) Number, duration, and results of
samples taken;
(E) Type of respiratory protective devices worn, if any; and
30
(4) Training. The employer shall
maintain all employee training records
for one (1) year beyond the last date of
employment of that employee.
(5) Availability. (i) The employer,
upon written request, shall make all
records required to be maintained by
this section available to the Assistant
Secretary and the Director for examination and copying.
(ii) The employer, upon request shall
make any exposure records required by
paragraph (m)(1) of this section available for examination and copying to affected employees, former employees,
designated representatives and the Assistant Secretary, in accordance with
29 CFR 1910.20 (a) through (e) and (g)
through (i).
(iii) The employer, upon request,
shall make employee medical records
required by paragraph (m)(3) of this
section available for examination and
copying to the subject employee, to
anyone having the specific written consent of the subject employee, and the
Assistant Secretary, in accordance
with 29 CFR 1910.20.
(6) Transfer of records. (i) The employer shall comply with the requirements concerning transfer of records
set forth in 29 CFR 1910.20(h).
(ii) Whenever the employer ceases to
do business and there is no successor
employer to receive and retain the
records for the prescribed period, the
employer shall notify the Director at
least 90 days prior to disposal of
records and, upon request, transmit
them to the Director.
(n) Observation of monitoring—(1) Employee observation. The employer shall
provide affected employees or their
designated representatives an opportunity to observe any monitoring of
employee exposure to asbestos conducted in accordance with paragraph
(d) of this section.
(2) Observation procedures. When observation of the monitoring of employee exposure to asbestos requires
entry into an area where the use of
protective clothing or equipment is required, the observer shall be provided
with and be required to use such clothing and equipment and shall comply
with all other applicable safety and
health procedures.
§ 1910.1001
(o) Dates—(1) Effective date. This
standard shall become effective October 11, 1994.
(2) The provisions of 29 CFR 1910.1001
remain in effect until the start-up
dates of the equivalent provisions of
this standard.
(3) Start-up dates. All obligations of
this standard commence on the effective date except as follows:
(i) Exposure monitoring. Initial monitoring required by paragraph (d)(2) of
this section shall be completed by October 1, 1995.
(ii) Regulated areas. Regulated areas
required to be established by paragraph
(e) of this section as a result of initial
monitoring shall be set up by October
1, 1995.
(iii)
Respiratory
protection.
Respiratory protection required by paragraph (g) of this section shall be provided by October 1, 1995.
(iv) Hygiene and lunchroom facilities.
Construction plans for change rooms,
showers, lavatories, and lunchroom facilities shall be completed by October
1, 1995.
(v) Communication of hazards. Identification, notification, labeling and sign
posting, and training required by paragraph (j) of this section shall be provided by October 1, 1995.
(vi) Medical surveillance. Medical surveillance not previously required by
paragraph (1) of this section shall be
provided by October 1, 1995.
(vii) Compliance program. Written
compliance programs required by paragraph (f)(2) of this section shall be
completed and available for inspection
and copying by October 1, 1995.11
(viii) Methods of compliance. The engineering and work practice controls as
required by paragraph (f) shall be implemented by October 1, 1995.
(p) Appendices. (1) Appendices A, C, D,
E, and F to this section are incorporated as part of this section and the
contents of these Appendices are mandatory.
(2) Appendices B, G, H, I, and J to
this section are informational and are
not intended to create any additional
obligations not otherwise imposed or
to detract from any existing obligations.
31
§ 1910.1001
and a numerical aperture of 0.65 to 0.75. The
microscope shall also be fitted with a green
or blue filter.
9. The microscope shall be fitted with a
Walton-Beckett eyepiece graticule calibrated for a field diameter of 100 micrometers (+/¥2 micrometers).
10. The phase-shift detection limit of the
microscope shall be about 3 degrees measured using the HSE phase shift test slide as
outlined below.
a. Place the test slide on the microscope
stage and center it under the phase objective.
b. Bring the blocks of grooved lines into
focus.
NOTE: The slide consists of seven sets of
grooved lines (ca. 20 grooves to each block)
in descending order of visibility from sets 1
to 7, seven being the least visible. The requirements for asbestos counting are that
the microscope optics must resolve the
grooved lines in set 3 completely, although
they may appear somewhat faint, and that
the grooved lines in sets 6 and 7 must be invisible. Sets 4 and 5 must be at least partially visible but may vary slightly in visibility between microscopes. A microscope
that fails to meet these requirements has either too low or too high a resolution to be
used for asbestos counting.
c. If the image deteriorates, clean and adjust the microscope optics. If the problem
persists, consult the microscope manufacturer.
11. Each set of samples taken will include
10% field blanks or a minimum of 2 field
blanks. These blanks must come from the
same lot as the filters used for sample collection. The field blank results shall be averaged and subtracted from the analytical results before reporting. A set consists of any
sample or group of samples for which an
evaluation for this standard must be made.
Any samples represented by a field blank
having a fiber count in excess of the detection limit of the method being used shall be
rejected.
12. The samples shall be mounted by the
acetone/triacetin method or a method with
an equivalent index of refraction and similar
clarity.
13. Observe the following counting rules.
a. Count only fibers equal to or longer than
5 micrometers. Measure the length of curved
fibers along the curve.
b. In the absence of other information,
count all particles as asbesto that have a
length-to-width ratio (aspect ratio) of 3:1 or
greater.
c. Fibers lying entirely within the boundary of the Walton-Beckett graticule field
shall receive a count of 1. Fibers crossing the
boundary once, having one end within the
circle, shall receive the count of one half
(1⁄2). Do not count any fiber that crosses the
graticule boundary more than once. Reject
APPENDIX A TO § 1910.1001—OSHA
REFERENCE METHOD—MANDATORY
This mandatory appendix specifies the procedure for analyzing air samples for asbestos
and specifies quality control procedures that
must be implemented by laboratories performing the analysis. The sampling and analytical methods described below represent
the elements of the available monitoring
methods (such as Appendix B of their regulation, the most current version of the OSHA
method ID–160, or the most current version
of the NIOSH Method 7400). All employers
who are required to conduct air monitoring
under paragraph (d) of the standard are required to utilize analytical laboratories that
use this procedure, or an equivalent method,
for collecting and analyzing samples.
Sampling and Analytical Procedure
1. The sampling medium for air samples
shall be mixed cellulose ester filter membranes. These shall be designated by the
manufacturer as suitable for asbestos counting. See below for rejection of blanks.
2. The preferred collection device shall be
the 25-mm diameter cassette with an openfaced 50-mm electrically conductive extension cowl. The 37-mm cassette may be used if
necessary but only if written justification
for the need to use the 37-mm filter cassette
accompanies the sample results in the employee’s exposure monitoring record. Do not
reuse or reload cassettes for asbestos sample
collection.
3. An air flow rate between 0.5 liter/min
and 2.5 liters/min shall be selected for the 25mm cassette. If the 37-mm cassette is used,
an air flow rate between 1 liter/min and 2.5
liters/min shall be selected.
4. Where possible, a sufficient air volume
for each air sample shall be collected to
yield between 100 and 1,300 fibers per square
millimeter on the membrane filter. If a filter
darkens in appearance or if loose dust is seen
on the filter, a second sample shall be started.
5. Ship the samples in a rigid container
with sufficient packing material to prevent
dislodging the collected fibers. Packing material that has a high electrostatic charge on
its surface (e.g., expanded polystyrene) cannot be used because such material can cause
loss of fibers to the sides of the cassette.
6. Calibrate each personal sampling pump
before and after use with a representative filter cassette installed between the pump and
the calibration devices.
7. Personal samples shall be taken in the
‘‘breathing zone’’ of the employee (i.e., attached to or near the collar or lapel near the
worker’s face).
8. Fiber counts shall be made by positive
phase contrast using a microscope with an 8
to 10 X eyepiece and a 40 to 45 X objective for
a total magnification of approximately 400 X
32
and do not count any other fibers even
though they may be visible outside the graticule area.
d. Count bundles of fibers as one fiber unless individual fibers can be identified by observing both ends of an individual fiber.
e. Count enough graticule fields to yield
100 fibers. Count a minimum of 20 fields; stop
counting at 100 fields regardless of fiber
count.
14. Blind recounts shall be conducted at
the rate of 10 percent.
§ 1910.1001
OSHA Permissible Exposure Limits:
Time Weighted Average ............. 0.1 fiber/cc
Excursion Level (30 minutes) ..... 1.0 fiber/cc
Collection Procedure:
A known volume of air is drawn through a 25-mm diameter
cassette containing a mixed-cellulose ester filter. The cassette must be equipped with an electrically conductive 50mm extension cowl. The sampling time and rate are chosen
to give a fiber density of between 100 to 1,300 fibers/mm2
on the filter.
Recommended Sampling Rate .......... 0.5 to 5.0 liters/minute
(L/min)
Recommended Air Volumes:
Minimum ..................................... 25 L
Maximum .................................... 2,400 L
Quality Control Procedures
1. Intralaboratory program. Each laboratory and/or each company with more than
one microscopist counting slides shall establish a statistically designed quality assurance program involving blind recounts and
comparisons between microscopists to monitor the variability of counting by each
microscopist and between microscopists. In a
company with more than one laboratory, the
program shall include all laboratories and
shall also evaluate the laboratory-to-laboratory variability.
2.a. Interlaboratory program. Each laboratory analyzing asbestos samples for compliance determination shall implement an
interlaboratory quality assurance program
that as a minimum includes participation of
at least two other independent laboratories.
Each laboratory shall participate in round
robin testing at least once every 6 months
with at least all the other laboratories in its
interlaboratory quality assurance group.
Each laboratory shall submit slides typical
of its own work load for use in this program.
The round robin shall be designed and results
analyzed using appropriate statistical methodology.
2.b. All laboratories should also participate
in a national sample testing scheme such as
the Proficiency Analytical Testing Program
(PAT), or the Asbestos Registry sponsored by
the American Industrial Hygiene Association
(AIHA).
3. All individuals performing asbestos analysis must have taken the NIOSH course for
sampling and evaluating airborne asbestos
dust or an equalivalent course.
4. When the use of different microscopes
contributes to differences between counters
and laboratories, the effect of the different
microscope shall be evaluated and the microscope shall be replaced, as necessary.
5. Current results of these quality assurance programs shall be posted in each laboratory to keep the microscopists informed.
Analytical Procedure: A portion of the
sample filter is cleared and prepared for asbestos fiber counting by Phase Contrast Microscopy (PCM) at 400X.
Commercial manufacturers and products
mentioned in this method are for descriptive
use only and do not constitute endorsements
by USDOL-OSHA. Similar products from
other sources can be substituted.
1. Introduction
This method describes the collection of
airborne asbestos fibers using calibrated
sampling pumps with mixed-cellulose ester
(MCE) filters and analysis by phase contrast
microscopy (PCM). Some terms used are
unique to this method and are defined below:
Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile,
crocidolite,
amosite
(cummingtonitegrunerite asbestos), tremolite asbestos, actinolite asbestos, anthophyllite asbestos, and
any of these minerals that have been chemically treated and/or altered. The precise
chemical formulation of each species will
vary with the location from which it was
mined. Nominal compositions are listed:
Chrysotile ............
Crocidolite ...........
Amosite ...............
Tremolite-actinolite.
Anthophyllite ......
Mg3 Si2 O5(OH)4
Na2 Fe32+ Fe23 +
Si8 O22 (OH)2
(Mg,Fe)7 Si8 O22
(OH)2
Ca2(Mg,Fe)5 Si8 O22
(OH)2
(Mg,Fe)7 Si8 O22
(OH)2
Asbestos Fiber: A fiber of asbestos which
meets the criteria specified below for a fiber.
Aspect Ratio: The ratio of the length of a
fiber to it’s diameter (e.g. 3:1, 5:1 aspect ratios).
Cleavage Fragments: Mineral particles
formed by comminution of minerals, especially those characterized by parallel sides
and a moderate aspect ratio (usually less
than 20:1).
Detection Limit: The number of fibers necessary to be 95% certain that the result is
greater than zero.
APPENDIX B TO § 1910.1001—DETAILED
PROCEDURES FOR ASBESTOS SAMPLING AND ANALYSIS—NON-MANDATORY
Matrix Air:
33
§ 1910.1001
Differential Counting: The term applied to
the practice of excluding certain kinds of fibers from the fiber count because they do
not appear to be asbestos.
Fiber: A particle that is 5 µ m or longer,
with a length-to-width ratio of 3 to 1 or
longer.
Field: The area within the graticule circle
that is superimposed on the microscope
image.
Set: The samples which are taken, submitted to the laboratory, analyzed, and for
which, interim or final result reports are
generated.
Tremolite, Anthophyllite, and Actinolite: The
non-asbestos form of these minerals which
meet the definition of a fiber. It includes any
of these minerals that have been chemically
treated and/or altered.
Walton-Beckett Graticule: An eyepiece graticule specifically designed for asbestos fiber
counting. It consists of a circle with a projected diameter of 100 2 µm (area of about
0.00785 mm2) with a crosshair having ticmarks at 3-µm intervals in one direction and
5-µm in the orthogonal direction. There are
marks around the periphery of the circle to
demonstrate the proper sizes and shapes of
fibers. This design is reproduced in Figure 1.
The disk is placed in one of the microscope
eyepieces so that the design is superimposed
on the field of view.
1.3. Advantages and Disadvantages
There are four main advantages of PCM
over other methods:
(1) The technique is specific for fibers.
Phase contrast is a fiber counting technique
which excludes non-fibrous particles from
the analysis.
(2) The technique is inexpensive and does
not require specialized knowledge to carry
out the analysis for total fiber counts.
(3) The analysis is quick and can be performed on-site for rapid determination of air
concentrations of asbestos fibers.
(4) The technique has continuity with historical epidemiological studies so that estimates of expected disease can be inferred
from long-term determinations of asbestos
exposures.
The main disadvantage of PCM is that it
does not positively identify asbestos fibers.
Other fibers which are not asbestos may be
included in the count unless differential
counting is performed. This requires a great
deal of experience to adequately differentiate asbestos from non-asbestos fibers. Positive identification of asbestos must be performed by polarized light or electron microscopy techniques. A further disadvantage of
PCM is that the smallest visible fibers are
about 0.2 µm in diameter while the finest asbestos fibers may be as small as 0.02 µm in
diameter. For some exposures, substantially
more fibers may be present than are actually
counted.
1.1. History
1.4. Workplace Exposure
Early surveys to determine asbestos exposures were conducted using impinger counts
of total dust with the counts expressed as
million particles per cubic foot. The British
Asbestos Research Council recommended filter membrane counting in 1969. In July 1969,
the Bureau of Occupational Safety and
Health published a filter membrane method
for counting asbestos fibers in the United
States. This method was refined by NIOSH
and published as P CAM 239. On May 29, 1971,
OSHA specified filter membrane sampling
with phase contrast counting for evaluation
of asbestos exposures at work sites in the
United States. The use of this technique was
again required by OSHA in 1986. Phase contrast microscopy has continued to be the
method of choice for the measurement of occupational exposure to asbestos.
Asbestos is used by the construction industry in such products as shingles, floor tiles,
asbestos cement, roofing felts, insulation
and acoustical products. Non-construction
uses include brakes, clutch facings, paper,
paints, plastics, and fabrics. One of the most
significant exposures in the workplace is the
removal and encapsulation of asbestos in
schools, public buildings, and homes. Many
workers have the potential to be exposed to
asbestos during these operations.
About 95% of the asbestos in commercial
use in the United States is chrysotile. Crocidolite and amosite make up most of the remainder. Anthophyllite and tremolite or actinolite are likely to be encountered as contaminants in various industrial products.
1.5. Physical Properties
Asbestos fiber possesses a high tensile
strength along its axis, is chemically inert,
non-combustible, and heat resistant. It has a
high electrical resistance and good sound absorbing properties. It can be weaved into cables, fabrics or other textiles, and also matted into asbestos papers, felts, or mats.
1.2. Principle
Air is drawn through a MCE filter to capture airborne asbestos fibers. A wedge shaped
portion of the filter is removed, placed on a
glass microscope slide and made transparent.
A measured area (field) is viewed by PCM.
All the fibers meeting defined criteria for asbestos are counted and considered a measure
of the airborne asbestos concentration.
2. Range and Detection Limit
2.1. The ideal counting range on the filter
is 100 to 1,300 fibers/mm2. With a Walton-
34
Beckett graticule this range is equivalent to
0.8 to 10 fibers/field. Using NIOSH counting
statistics, a count of 0.8 fibers/field would
give an approximate coefficient of variation
(CV) of 0.13.
2.2. The detection limit for this method is
4.0 fibers per 100 fields or 5.5 fibers/mm2. This
was determined using an equation to estimate the maximum CV possible at a specific
concentration (95% confidence) and a Lower
Control Limit of zero. The CV value was
then used to determine a corresponding concentration from historical CV vs fiber relationships. As an example:
Lower Control Limit (95% Confidence) = AC
¥ 1.645(CV)(AC)
Where:
AC = Estimate of the airborne fiber concentration (fibers/cc) Setting the Lower
Control Limit = 0 and solving for CV:
0 = AC ¥ 1.645(CV)(AC)
CV = 0.61
§ 1910.1001
gypsum
some synthetic fibers
membrane structures
sponge spicules
diatoms
microorganisms
wollastonite
The use of electron microscopy or optical
tests such as polarized light, and dispersion
staining may be used to differentiate these
materials from asbestos when necessary.
5. Sampling
5.1. Equipment
5.1.1. Sample assembly (The assembly is
shown in Figure 3). Conductive filter holder
consisting of a 25-mm diameter, 3-piece cassette having a 50-mm long electrically conductive extension cowl. Backup pad, 25-mm,
cellulose. Membrane filter, mixed-cellulose
ester (MCE), 25-mm, plain, white, 0.4 to 1.2µm pore size.
Notes: (a) Do not re-use cassettes.
(b) Fully conductive cassettes are required
to reduce fiber loss to the sides of the cassette due to electrostatic attraction.
(c) Purchase filters which have been selected by the manufacturer for asbestos
counting or analyze representative filters for
fiber background before use. Discard the filter lot if more than 4 fibers/100 fields are
found.
(d) To decrease the possibility of contamination, the sampling system (filter-backup
pad-cassette)
for
asbestos
is
usually
preassembled by the manufacturer.
(e) Other cassettes, such as the Bellmouth, may be used within the limits of
their validation.
5.1.2. Gel bands for sealing cassettes.
5.1.3. Sampling pump.
Each pump must be a battery operated,
self-contained unit small enough to be
placed on the monitored employee and not
interfere with the work being performed. The
pump must be capable of sampling at the collection rate for the required sampling time.
5.1.4. Flexible tubing, 6-mm bore.
5.1.5. Pump calibration.
Stopwatch and bubble tube/burette or electronic meter.
5.2. Sampling Procedure
5.2.1. Seal the point where the base and
cowl of each cassette meet with a gel band or
tape.
5.2.2. Charge the pumps completely before
beginning.
5.2.3. Connect each pump to a calibration
cassette with an appropriate length of 6-mm
bore plastic tubing. Do not use luer connectors—the type of cassette specified above has
built-in adapters.
5.2.4. Select an appropriate flow rate for
the situation being monitored. The sampling
flow rate must be between 0.5 and 5.0 L/min
for personal sampling and is commonly set
This value was compared with CV vs. count
curves. The count at which CV = 0.61 for
Leidel-Busch counting statistics or for an
OSHA Salt Lake Technical Center (OSHA–
SLTC) CV curve (see Appendix A for further
information) was 4.4 fibers or 3.9 fibers per
100 fields, respectively. Although a lower detection limit of 4 fibers per 100 fields is supported by the OSHA–SLTC data, both data
sets support the 4.5 fibers per 100 fields value.
3. Method Performance—Precision and
Accuracy
Precision is dependent upon the total number of fibers counted and the uniformity of
the fiber distribution on the filter. A general
rule is to count at least 20 and not more than
100 fields. The count is discontinued when 100
fibers are counted, provided that 20 fields
have already been counted. Counting more
than 100 fibers results in only a small gain in
precision. As the total count drops below 10
fibers, an accelerated loss of precision is
noted.
At this time, there is no known method to
determine the absolute accuracy of the asbestos analysis. Results of samples prepared
through the Proficiency Analytical Testing
(PAT) Program and analyzed by the OSHA–
SLTC showed no significant bias when compared to PAT reference values. The PAT
samples were analyzed from 1987 to 1989
(N=36) and the concentration range was from
120 to 1,300 fibers/mm2.
4. Interferences
Fibrous substances, if present, may interfere with asbestos analysis.
Some common fibers are:
fiberglass
anhydrite
plant fibers
perlite veins
35
§ 1910.1001
between 1 and 2 L/min. Always choose a flow
rate that will not produce overloaded filters.
5.2.5. Calibrate each sampling pump before
and after sampling with a calibration cassette in-line (Note: This calibration cassette
should be from the same lot of cassettes used
for sampling). Use a primary standard (e.g.
bubble burette) to calibrate each pump. If
possible, calibrate at the sampling site.
sample handling. Prepare two blanks for the
first 1 to 20 samples. For sets containing
greater than 20 samples, prepare blanks as
10% of the samples. Handle blank samples in
the same manner as air samples with one exception: Do not draw any air through the
blank samples. Open the blank cassette in
the place where the sample cassettes are
mounted on the employee. Hold it open for
about 30 seconds. Close and seal the cassette
appropriately. Store blanks for shipment
with the sample cassettes.
5.2.10. Immediately after sampling, close
and seal each cassette with the base and
plastic plugs. Do not touch or puncture the
filter membrane as this will invalidate the
analysis.
5.2.11 Attach and secure a sample seal
around each sample cassette in such a way
as to assure that the end cap and base plugs
cannot be removed without destroying the
seal. Tape the ends of the seal together since
the seal is not long enough to be wrapped
end-to-end. Also wrap tape around the cassette at each joint to keep the seal secure.
NOTE: If sampling site calibration is not
possible, environmental influences may affect the flow rate. The extent is dependent
on the type of pump used. Consult with the
pump manufacturer to determine dependence
on environmental influences. If the pump is
affected by temperature and pressure
changes, correct the flow rate using the formula shown in the section ‘‘Sampling Pump
Flow Rate Corrections’’ at the end of this appendix.
5.2.6. Connect each pump to the base of
each sampling cassette with flexible tubing.
Remove the end cap of each cassette and
take each air sample open face. Assure that
each sample cassette is held open side down
in the employee’s breathing zone during
sampling. The distance from the nose/mouth
of the employee to the cassette should be
about 10 cm. Secure the cassette on the collar or lapel of the employee using spring
clips or other similar devices.
5.2.7. A suggested minimum air volume
when sampling to determine TWA compliance is 25 L. For Excursion Limit (30 min
sampling time) evaluations, a minimum air
volume of 48 L is recommended.
5.2.8. The most significant problem when
sampling for asbestos is overloading the filter with non-asbestos dust. Suggested maximum air sample volumes for specific environments are:
Environment
Asbestos removal operations (visible dust) .......
Asbestos removal operations (little dust) ...........
Office environments ...........................................
5.3. Sample Shipment
5.3.1. Send the samples to the laboratory
with paperwork requesting asbestos analysis.
List any known fibrous interferences present
during sampling on the paperwork. Also,
note the workplace operation(s) sampled.
5.3.2. Secure and handle the samples in
such that they will not rattle during shipment nor be exposed to static electricity. Do
not ship samples in expanded polystyrene
peanuts, vermiculite, paper shreds, or excelsior. Tape sample cassettes to sheet bubbles
and place in a container that will cushion
the samples in such a manner that they will
not rattle.
5.3.3. To avoid the possibility of sample
contamination, always ship bulk samples in
separate mailing containers.
Air vol. (L)
100
240
400
to
2,400
6. Analysis
6.1. Safety Precautions
6.1.1. Acetone is extremely flammable and
precautions must be taken not to ignite it.
Avoid using large containers or quantities of
acetone. Transfer the solvent in a ventilated
laboratory hood. Do not use acetone near
any open flame. For generation of acetone
vapor, use a spark free heat source.
6.1.2. Any asbestos spills should be cleaned
up immediately to prevent dispersal of fibers. Prudence should be exercised to avoid
contamination of laboratory facilities or exposure of personnel to asbestos. Asbestos
spills should be cleaned up with wet methods
and/or a High Efficiency Particulate-Air
(HEPA) filtered vacuum.
Caution: Do not use a vacuum without a
HEPA filter—It will disperse fine asbestos fibers in the air.
Caution: Do not overload the filter with
dust. High levels of non-fibrous dust particles may obscure fibers on the filter and
lower the count or make counting impossible. If more than about 25 to 30% of the
field area is obscured with dust, the result
may be biased low. Smaller air volumes may
be necessary when there is excessive non-asbestos dust in the air.
While sampling, observe the filter with a
small flashlight. If there is a visible layer of
dust on the filter, stop sampling, remove and
seal the cassette, and replace with a new
sampling assembly. The total dust loading
should not exceed 1 mg.
5.2.9. Blank samples are used to determine
if any contamination has occurred during
36
6.2. Equipment
§ 1910.1001
surface that can be damaged by either the
heat or from exposure to acetone.
6.5.2. Ensure that the glass slides and cover
glasses are free of dust and fibers.
6.5.3. Remove the top plug to prevent a
vacuum when the cassette is opened. Clean
the outside of the cassette if necessary. Cut
the seal and/or tape on the cassette with a
razor blade. Very carefully separate the base
from the extension cowl, leaving the filter
and backup pad in the base.
6.5.4. With a rocking motion cut a triangular wedge from the filter using the scalpel. This wedge should be one-sixth to onefourth of the filter. Grasp the filter wedge
with the forceps on the perimeter of the filter which was clamped between the cassette
pieces. DO NOT TOUCH the filter with your
finger. Place the filter on the glass slide
sample side up. Static electricity will usually keep the filter on the slide until it is
cleared.
6.5.5. Place the tip of the micropipette containing about 200 µ L acetone into the aluminum block. Insert the glass slide into the
receiving slot in the aluminum block. Inject
the acetone into the block with slow, steady
pressure on the plunger while holding the pipette firmly in place. Wait 3 to 5 seconds for
the filter to clear, then remove the pipette
and slide from the aluminum block.
6.5.6. Immediately (less than 30 seconds)
place 2.5 to 3.5 µ L of triacetin on the filter
(Note: Waiting longer than 30 seconds will
result in increased index of refraction and
decreased contrast between the fibers and
the preparation. This may also lead to separation of the cover slip from the slide).
6.5.7. Lower a cover slip gently onto the filter at a slight angle to reduce the possibility
of forming air bubbles. If more than 30 seconds have elapsed between acetone exposure
and triacetin application, glue the edges of
the cover slip to the slide with lacquer or
nail polish.
6.5.8. If clearing is slow, warm the slide for
15 min on a hot plate having a surface temperature of about 50 °C to hasten clearing.
The top of the hot block can be used if the
slide is not heated too long.
6.5.9. Counting may proceed immediately
after clearing and mounting are completed.
6.2.1. Phase contrast microscope with binocular or trinocular head.
6.2.2. Widefield or Huygenian 10X eyepieces
(NOTE: The eyepiece containing the graticule
must be a focusing eyepiece. Use a 40X phase
objective with a numerical aperture of 0.65 to
0.75).
6.2.3. Kohler illumination (if possible) with
green or blue filter.
6.2.4. Walton-Beckett Graticule, type G–22
with 100 ± 2 µm projected diameter.
6.2.5. Mechanical stage.
A rotating mechanical stage is convenient
for use with polarized light.
6.2.6. Phase telescope.
6.2.7. Stage micrometer with 0.01–mm subdivisions.
6.2.8. Phase-shift test slide, mark II (Available from PTR optics Ltd., and also
McCrone).
6.2.9. Precleaned glass slides, 25 mm X 75
mm. One end can be frosted for convenience
in writing sample numbers, etc., or paste-on
labels can be used.
6.2.10. Cover glass #1 1⁄2.
6.2.11. Scalpel (#10, curved blade).
6.2.12. Fine tipped forceps.
6.2.13. Aluminum block for clearing filter
(see Appendix D and Figure 4).
6.2.14. Automatic adjustable pipette, 100- to
500-µ L.
6.2.15. Micropipette, 5 µ L.
6.3. Reagents
6.3.1. Acetone (HPLC grade).
6.3.2. Triacetin (glycerol triacetate).
6.3.3. Lacquer or nail polish.
6.4. Standard Preparation
A way to prepare standard asbestos samples of known concentration has not been developed. It is possible to prepare replicate
samples of nearly equal concentration. This
has been performed through the PAT program. These asbestos samples are distributed
by the AIHA to participating laboratories.
Since only about one-fourth of a 25–mm
sample membrane is required for an asbestos
count, any PAT sample can serve as a
‘‘standard’’ for replicate counting.
6.5. Sample Mounting
6.6. Sample Analysis
NOTE: See Safety Precautions in Section
6.1. before proceeding. The objective is to
produce samples with a smooth (non-grainy)
background in a medium with a refractive
index of approximately 1.46. The technique
below collapses the filter for easier focusing
and produces permanent mounts which are
useful for quality control and interlaboratory comparison.
An aluminum block or similar device is required for sample preparation.
6.5.1. Heat the aluminum block to about 70
°C. The hot block should not be used on any
Completely align the microscope according
to the manufacturer’s instructions. Then,
align the microscope using the following
general alignment routine at the beginning
of every counting session and more often if
necessary.
6.6.1. Alignment
(1) Clean all optical surfaces. Even a small
amount of dirt can significantly degrade the
image.
(2) Rough focus the objective on a sample.
37
§ 1910.1001
(3) Close down the field iris so that it is
visible in the field of view. Focus the image
of the iris with the condenser focus. Center
the image of the iris in the field of view.
(4) Install the phase telescope and focus on
the phase rings. Critically center the rings.
Misalignment of the rings results in astigmatism which will degrade the image.
(5) Place the phase-shift test slide on the
microscope stage and focus on the lines. The
analyst must see line set 3 and should see at
least parts of 4 and 5 but, not see line set 6
or 6. A microscope/microscopist combination
which does not pass this test may not be
used.
(10) Record the number of fibers in each
field in a consistent way such that filter
non-uniformity can be assessed.
(11) Regularly check phase ring alignment.
(12) When an agglomerate (mass of material) covers more than 25% of the field of
view, reject the field and select another. Do
not include it in the number of fields counted.
(13) Perform a ‘‘blind recount’’ of 1 in every
10 filter wedges (slides). Re-label the slides
using a person other than the original
counter.
6.7. Fiber Identification
As previously mentioned in Section 1.3.,
PCM does not provide positive confirmation
of asbestos fibers. Alternate differential
counting techniques should be used if discrimination is desirable. Differential counting may include primary discrimination
based on morphology, polarized light analysis of fibers, or modification of PCM data
by Scanning Electron or Transmission Electron Microscopy.
A great deal of experience is required to
routinely and correctly perform differential
counting. It is discouraged unless it is legally necessary. Then, only if a fiber is obviously not asbestos should it be excluded from
the count. Further discussion of this technique can be found in reference 8.10.
If there is a question whether a fiber is asbestos or not, follow the rule:
‘‘WHEN IN DOUBT, COUNT.’’
6.8. Analytical Recommendations—Quality
Control System
6.8.1. All individuals performing asbestos
analysis must have taken the NIOSH course
for sampling and evaluating airborne asbestos or an equivalent course.
6.8.2. Each laboratory engaged in asbestos
counting shall set up a slide trading arrangement with at least two other laboratories in
order to compare performance and eliminate
inbreeding of error. The slide exchange occurs at least semiannually. The round robin
results shall be posted where all analysts can
view individual analyst’s results.
6.8.3. Each laboratory engaged in asbestos
counting shall participate in the Proficiency
Analytical Testing Program, the Asbestos
Analyst Registry or equivalent.
6.8.4. Each analyst shall select and count
prepared slides from a ‘‘slide bank’’. These
are quality assurance counts. The slide bank
shall be prepared using uniformly distributed
samples taken from the workload. Fiber densities should cover the entire range routinely
analyzed by the laboratory. These slides are
counted blind by all counters to establish an
original standard deviation. This historical
distribution is compared with the quality assurance counts. A counter must have 95% of
all quality control samples counted within
three standard deviations of the historical
mean. This count is then integrated into a
6.6.2. Counting Fibers
(1) Place the prepared sample slide on the
mechanical stage of the microscope. Position
the center of the wedge under the objective
lens and focus upon the sample.
(2) Start counting from one end of the
wedge and progress along a radial line to the
other end (count in either direction from perimeter to wedge tip). Select fields randomly, without looking into the eyepieces,
by slightly advancing the slide in one direction with the mechanical stage control.
(3) Continually scan over a range of focal
planes (generally the upper 10 to 15 µ m of
the filter surface) with the fine focus control
during each field count. Spend at least 5 to
15 seconds per field.
(4) Most samples will contain asbestos fibers with fiber diameters less than 1 µ m.
Look carefully for faint fiber images. The
small diameter fibers will be very hard to
see. However, they are an important contribution to the total count.
(5) Count only fibers equal to or longer
than 5 µ m. Measure the length of curved fibers along the curve.
(6) Count fibers which have a length to
width ratio of 3:1 or greater.
(7) Count all the fibers in at least 20 fields.
Continue counting until either 100 fibers are
counted or 100 fields have been viewed;
whichever occurs first. Count all the fibers
in the final field.
(8) Fibers lying entirely within the boundary of the Walton-Beckett graticule field
shall receive a count of 1. Fibers crossing the
boundary once, having one end within the
circle shall receive a count of 1⁄2. Do not
count any fiber that crosses the graticule
boundary more than once. Reject and do not
count any other fibers even though they may
be visible outside the graticule area. If a
fiber touches the circle, it is considered to
cross the line.
(9) Count bundles of fibers as one fiber unless individual fibers can be clearly identified and each individual fiber is clearly not
connected to another counted fiber. See Figure 1 for counting conventions.
38
new historical mean and standard deviation
for the slide.
The analyses done by the counters to establish the slide bank may be used for an interim quality control program if the data are
treated in a proper statistical fashion.
7.3. Recount Calculations
As mentioned in step 13 of Section 6.6.2., a
‘‘blind recount’’ of 10% of the slides is performed. In all cases, differences will be observed between the first and second counts of
the same filter wedge. Most of these differences will be due to chance alone, that is,
due to the random variability (precision) of
the count method. Statistical recount criteria enables one to decide whether observed
differences can be explained due to chance
alone or are probably due to systematic differences between analysts, microscopes, or
other biasing factors.
The following recount criterion is for a
pair of counts that estimate AC in fibers/cc.
The criterion is given at the type-I error
level. That is, there is 5% maximum risk
that we will reject a pair of counts for the
reason that one might be biased, when the
large observed difference is really due to
chance.
Reject a pair of counts if:
7. Calculations
7.1. Calculate the estimated airborne asbestos fiber concentration on the filter sample
using the following formula:
where:
AC = Airborne fiber concentration
AC =
 FB   BFB  
 −
  × ECA

 FL   BFL  
1000 × FR × T × MFA
FB = Total number of fibers greater than 5 µ
m counted
FL = Total number of fields counted on the
filter
BFB = Total number of fibers greater than 5
µ m counted in the blank
BFL = Total number of fields counted on the
blank
ECA = Effective collecting area of filter (385
mm2 nominal for a 25-mm filter.)
FR = Pump flow rate (L/min)
MFA = Microscope count field area (mm2).
This is 0.00785 mm2 for a Walton-Beckett
Graticule.
T = Sample collection time (min)
1,000 = Conversion of L to cc
NOTE: The collection area of a filter is seldom equal to 385 mm2. It is appropriate for
laboratories to routinely monitor the exact
diameter using an inside micrometer. The
collection area is calculated according to the
formula:
Area = π(d/2)2
AC 2 − AC1 > 2.78
×
(
)
AC AVG × CVFB
Where:
AC1=lower estimated airborne fiber concentration
AC2=higher estimated airborne fiber concentration
ACavg=average of the two concentration
estimates
CVFB=CV for the average of the two concentration estimates
If a pair of counts are rejected by this criterion then, recount the rest of the filters in
the submitted set. Apply the test and reject
any other pairs failing the test. Rejection
shall include a memo to the industrial hygienist stating that the sample failed a statistical test for homogeneity and the true air
concentration may be significantly different
than the reported value.
7.2. Short-cut Calculation
Since a given analyst always has the same
interpupillary distance, the number of fields
per filter for a particular analyst will remain
constant for a given size filter. The field size
for that analyst is constant (i.e. the analyst
is using an assigned microscope and is not
changing the reticle).
For example, if the exposed area of the filter is always 385 mm2 and the size of the field
is always 0.00785 mm2, the number of fields
per filter will always be 49,000. In addition it
is necessary to convert liters of air to cc.
These three constants can then be combined
such that ECA/(1,000 X MFA)=49. The previous equation simplifies to:
AC =
§ 1910.1001
7.4. Reporting Results
Report results to the industrial hygienist
as fibers/cc. Use two significant figures. If
multiple analyses are performed on a sample, an average of the results is to be reported unless any of the results can be rejected for cause.
8. References
 FB   BFB 

 −
 × 49
 FL   BFL 
8.1. Dreesen, W.C., et al, U.S. Public Health
Service: A Study of Asbestosis in the Asbestos
Textile Industry, (Public Health Bulletin No.
241), US Treasury Dept., Washington, DC,
1938.
FR × T
39
§ 1910.1001
B = ¥0.973343
C = 0.327499
Using these values, the equation becomes:
[0.182205(log10
CV
=
antilog10
(x))2¥0.973343(log10 (x))+0.327499]
8.2. Asbestos Research Council: The Measurement of Airborne Asbestos Dust by the Membrane Filter Method (Technical Note), Asbestos Research Council, Rockdale, Lancashire,
Great Britain, 1969.
8.3. Bayer, S.G., Zumwalde, R.D., Brown,
T.A., Equipment and Procedure for Mounting
Millipore Filters and Counting Asbestos Fibers
by Phase Contrast Microscopy, Bureau of Occupational Health, U.S. Dept. of Health, Education and Welfare, Cincinnati, OH, 1969.
8.4. NIOSH Manual of Analytical Methods,
2nd ed., Vol. 1 (DHEW/NIOSH Pub. No. 77–
157–A). National Institute for Occupational
Safety and Health, Cincinnati, OH, 1977. pp.
239–1-239–21.
8.5. Asbestos, Code of Federal Regulations
29 CFR 1910.1001. 1971.
8.6. Occupational Exposure to Asbestos,
Tremolite, Anthophyllite, and Actinolite. Final
Rule, FEDERAL REGISTER 51:119 (20 June 1986).
pp.22612–22790.
8.7. Asbestos, Tremolite, Anthophyllite, and
Actinolite, Code of Federal Regulations
1910.1001. 1988. pp 711–752.
8.8. Criteria for a Recommended Standard—
Occupational Exposure to Asbestos (DHEW/
NIOSH Pub. No. HSM 72–10267), National Institute for Occupational Safety and Health
NIOSH, Cincinnati,OH, 1972. pp. III–1–III–24.
8.9. Leidel, N.A., Bayer,S.G., Zumwalde,
R.D.,Busch, K.A., USPHS/NIOSH Membrane
Filter Method for Evaluating Airborne Asbestos
Fibers (DHEW/NIOSH Pub. No. 79–127). National Institute for Occupational Safety and
Health, Cincinnati, OH, 1979.
8.10. Dixon, W.C., Applications of Optical Microscopy in Analysis of Asbestos and Quartz,
Analytical Techniques in Occupational
Health Chemistry, edited by D.D. Dollberg
and A.W. Verstuyft. Wash. DC: American
Chemical Society, (ACS Symposium Series
120) 1980. pp. 13–41.
Sampling Pump Flow Rate Corrections
This correction is used if a difference
greater than 5% in ambient temperature and/
or pressure is noted between calibration and
sampling sites and the pump does not compensate for the differences.
P  T 
Q act = Q cal ×  cal  ×  act 
 Pact   Tcal 
Where:
Qact = actual flow rate
Qcal = calibrated flow rate (if a rotameter was
used, the rotameter value)
Pcal = uncorrected air pressure at calibration
Pact = uncorrected air pressure at sampling
site
Tact = temperature at sampling site (K)
Tcal = temperature at calibration (K)
Walton-Beckett Graticule
When ordering the Graticule for asbestos
counting, specify the exact disc diameter
needed to fit the ocular of the microscope
and the diameter (mm) of the circular counting area. Instructions for measuring the dimensions necessary are listed:
(1) Insert any available graticule into the
focusing eyepiece and focus so that the graticule lines are sharp and clear.
(2) Align the microscope.
(3) Place a stage micrometer on the microscope object stage and focus the microscope
on the graduated lines.
(4) Measure the magnified grid length, PL
(µ m), using the stage micrometer.
(5) Remove the graticule from the microscope and measure its actual grid length, AL
(mm). This can be accomplished by using a
mechanical stage fitted with verniers, or a
jeweler’s loupe with a direct reading scale.
(6) Let D=100 µ m. Calculate the circle diameter, dc (mm), for the Walton-Beckett
graticule and specify the diameter when
making a purchase:
Quality Control
The OSHA asbestos regulations require
each laboratory to establish a quality control program. The following is presented as
an example of how the OSHA-SLTC constructed its internal CV curve as part of
meeting this requirement. Data is from 395
samples collected during OSHA compliance
inspections and analyzed from October 1980
through April 1986.
Each sample was counted by 2 to 5 different counters independently of one another. The standard deviation and the CV
statistic was calculated for each sample.
This data was then plotted on a graph of CV
vs. fibers/mm2. A least squares regression
was performed using the following equation:
CV = antilog110[A(log10(x))2+B(log10(x))+C]
where:
x = the number of fibers/mm2
Application of least squares gave:
A = 0.182205
dc =
AL × D
PL
Example: If PL=108 µ m, AL=2.93 mm and
D=100 µ m, then,
dc =
2.93 × 100
108
= 2.71mm
(7) Each eyepiece-objective-reticle combination on the microscope must be calibrated. Should any of the three be changed
40
(by zoom adjustment, disassembly, replacement, etc.), the combination must be recalibrated. Calibration may change if interpupillary distance is changed. Measure the field
diameter, D (acceptable range: 100±2 µ m)
with a stage micrometer upon receipt of the
graticule from the manufacturer. Determine
the field area (mm2).
Field Area = >(D/2)2
If D=100 µ m=0.1 mm, then
Field Area=>(0.1 mm/2)2=0.00785 mm2
The Graticule is available from: Graticules
Ltd., Morley Road, Tonbridge TN9 IRN,
Kent, England (Telephone 011–44–732–359061).
Also available from PTR Optics Ltd., 145
Newton Street, Waltham, MA 02154 [telephone (617) 891–6000] or McCrone Accessories
§ 1910.1001
and Components, 2506 S. Michigan Ave., Chicago, IL 60616 [phone (312)-842–7100]. The
graticule is custom made for each microscope.
COUNTS FOR THE FIBERS IN THE FIGURE
Structure No.
1 to 6 .........
7
8
9
10
11
12
41
................
................
................
................
................
................
Count
Explanation
1
⁄
0
2
0
0
1⁄2
12
Single fibers all contained within
the circle.
Fiber crosses circle once.
Fiber too short.
Two crossing fibers.
Fiber outside graticule.
Fiber crosses graticule twice.
Although split, fiber only crosses
once.
§ 1910.1001
gram. Part 1 of the appendix contains the
Initial Medical Questionnaire, which must be
obtained for all new hires who will be covered by the medical surveillance requirements. Part 2 includes the abbreviated Periodical Medical Questionnaire, which must be
administered to all employees who are provided periodic medical examinations under
the medical surveillance provisions of the
standard.
APPENDIX C TO § 1910.1001 [RESERVED]
APPENDIX D TO § 1910.1001—MEDICAL
QUESTIONNAIRES; MANDATORY
This mandatory appendix contains the
medical questionnaires that must be administered to all employees who are exposed to
asbestos above the permissible exposure
limit, and who will therefore be included in
their employer’s medical surveillance pro-
42
43
§ 1910.1001
§ 1910.1001
44
45
§ 1910.1001
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46
47
§ 1910.1001
§ 1910.1001
48
49
§ 1910.1001
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50
51
§ 1910.1001
§ 1910.1001
52
53
§ 1910.1001
§ 1910.1001
APPENDIX E TO § 1910.1001—INTERPRETATION AND CLASSIFICATION OF CHEST
ROENTGENOGRAMS—MANDATORY
APPENDIX F TO § 1910.1001—WORK PRACTICES AND ENGINEERING CONTROLS
FOR AUTOMOTIVE BRAKE AND CLUTCH
INSPECTION, DISASSEMBLY, REPAIR
AND ASSEMBLY—MANDATORY
(a) Chest roentgenograms shall be interpreted and classified in accordance with a
professionally accepted Classification system and recorded on an interpretation form
following the format of the CDC/NIOSH (M)
2.8 form. As a minimum, the content within
the bold lines of this form (items 1 though 4)
shall be included. This form is not to be submitted to NIOSH.
(b) Roentgenograms shall be interpreted
and classified only by a B-reader, a board eligible/certified radiologist, or an experienced
physician
with
known
expertise
in
pneumoconioses.
(c) All interpreters, whenever interpreting
chest roentgenograms made under this section, shall have immediately available for
reference a complete set of the ILO–U/C
International Classification of Radiographs
for Pneumoconioses, 1980.
This mandatory appendix specifies engineering controls and work practices that
must be implemented by the employer during automotive brake and clutch inspection,
disassembly, repair, and assembly operations. Proper use of these engineering controls and work practices by trained employees will reduce employees’ asbestos exposure
below the permissible exposure level during
clutch and brake inspection, disassembly, repair, and assembly operations. The employer
shall institute engineering controls and
work practices using either the method set
forth in paragraph [A] or paragraph [B] of
this appendix, or any other method which
the employer can demonstrate to be equivalent in terms of reducing employee exposure
to asbestos as defined and which meets the
54
requirements described in paragraph [C] of
this appendix, for those facilities in which no
more than 5 pairs of brakes or 5 clutches are
inspected, disassembled, reassembled and/or
repaired per week, the method set forth in
paragraph [D] of this appendix may be used:
§ 1910.1001
(5) The brake support plate, brake shoes
and brake components used to attach the
brake shoes shall be thoroughly washed before removing the old shoes.
(6) In systems using filters, the filters,
when full, shall be first wetted with a fine
mist of water, then removed and placed immediately in an impermeable container, labeled according to paragraph (j)(4) of this
section and disposed of according to paragraph (k) of this section.
(7) Any spills of asbestos-containing aqueous solution or any asbestos-containing
waste material shall be cleaned up immediately and disposed of according to paragraph (k) of this section.
(8) The use of dry brushing during low pressure/wet cleaning operations is prohibited.
[A] Negative Pressure Enclosure/HEPA Vacuum
System Method
(1) The brake and clutch inspection, disassembly, repair, and assembly operations
shall be enclosed to cover and contain the
clutch or brake assembly and to prevent the
release of asbestos fibers into the worker’s
breathing zone.
(2) The enclosure shall be sealed tightly
and thoroughly inspected for leaks before
work begins on brake and clutch inspection,
disassembly, repair, and assembly.
(3) The enclosure shall be such that the
worker can clearly see the operation and
shall provide impermeable sleeves through
which the worker can handle the brake and
clutch inspection, disassembly, repair and
assembly. The integrity of the sleeves and
ports shall be examined before work begins.
(4) A HEPA-filtered vacuum shall be employed to maintain the enclosure under negative pressure throughout the operation.
Compressed-air may be used to remove asbestos fibers or particles from the enclosure.
(5) The HEPA vacuum shall be used first to
loosen the asbestos containing residue from
the brake and clutch parts and then to evacuate the loosened asbestos containing material from the enclosure and capture the material in the vacuum filter.
(6) The vacuum’s filter, when full, shall be
first wetted with a fine mist of water, then
removed and placed immediately in an impermeable container, labeled according to
paragraph (j)(4) of this section and disposed
of according to paragraph (k) of this section.
(7) Any spills or releases of asbestos containing waste material from inside of the enclosure or vacuum hose or vacuum filter
shall be immediately cleaned up and disposed of according to paragraph (k) of this
section.
[C] Equivalent Methods
An equivalent method is one which has sufficient written detail so that it can be reproduced and has been demonstrated that the
exposures resulting from the equivalent
method are equal to or less than the exposures which would result from the use of the
method described in paragraph [A] of this appendix. For purposes of making this comparison, the employer shall assume that exposures resulting from the use of the method
described in paragraph [A] of this appendix
shall not exceed 0.016 f/cc, as measured by
the OSHA reference method and as averaged
over at least 18 personal samples.
[D] Wet Method.
(1) A spray bottle, hose nozzle, or other implement capable of delivering a fine mist of
water or amended water or other delivery
system capable of delivering water at low
pressure, shall be used to first thoroughly
wet the brake and clutch parts. Brake and
clutch components shall then be wiped clean
with a cloth.
(2) The cloth shall be placed in an impermeable container, labelled according to paragraph (j)(4) of this section and then disposed
of according to paragraph (k) of this section,
or the cloth shall be laundered in a way to
prevent the release of asbestos fibers in excess of 0.1 fiber per cubic centimeter of air.
(3) Any spills of solvent or any asbestos
containing waste material shall be cleaned
up immediately according to paragraph (k)
of this section.
(4) The use of dry brushing during the wet
method operations is prohibited.
[B] Low Pressure/Wet Cleaning Method
(1) A catch basin shall be placed under the
brake assembly, positioned to avoid splashes
and spills.
(2) The reservoir shall contain water containing an organic solvent or wetting agent.
The flow of liquid shall be controlled such
that the brake assembly is gently flooded to
prevent the asbestos-containing brake dust
from becoming airborne.
(3) The aqueous solution shall be allowed
to flow between the brake drum and brake
support before the drum is removed.
(4) After removing the brake drum, the
wheel hub and back of the brake assembly
shall be thoroughly wetted to suppress dust.
APPENDIX G TO § 1910.1001—SUBSTANCE
TECHNICAL INFORMATION FOR ASBESTOS—NON-MANDATORY
I. Substance Identification
A. Substance: ‘‘Asbestos’’ is the name of a
class of magnesium-silicate minerals that
55
§ 1910.1001
occur in fibrous form. Minerals that are included in this group are chrysotile, crocidolite,
amosite,
tremolite
asbestos,
anthophyllite asbestos, and actinolite asbestos.
B. Asbestos is used in the manufacture of
heat-resistant clothing, automative brake
and clutch linings, and a variety of building
materials including floor tiles, roofing felts,
ceiling tiles, asbestos-cement pipe and sheet,
and fire-resistant drywall. Asbestos is also
present in pipe and boiler insulation materials, and in sprayed-on materials located on
beams, in crawlspaces, and between walls.
C. The potential for a product containing
asbestos to release breatheable fibers depends on its degree of friability. Friable
means that the material can be crumbled
with hand pressure and is therefore likely to
emit fibers. The fibrous or fluffy sprayed-on
materials used for fireproofing, insulation,
or sound proofing are considered to be friable, and they readily release airborne fibers
if disturbed. Materials such as vinyl-asbestos
floor tile or roofing felts are considered nonfriable and generally do not emit airborne fibers unless subjected to sanding or sawing
operations. Asbestos-cement pipe or sheet
can emit airborne fibers if the materials are
cut or sawed, or if they are broken during
demolition operations.
D. Permissible exposure: Exposure to airborne asbestos fibers may not exceed 0.2 fibers per cubic centimeter of air (0.1 f/cc)
averaged over the 8-hour workday.
centrations do not exceed 2 f/cc; otherwise,
air-supplied, positive-pressure, full facepiece
respirators must be used. Disposable respirators or dust masks are not permitted to
be used for asbestos work. For effective protection, respirators must fit your face and
head snugly. Your employer is required to
conduct fit tests when you are first assigned
a respirator and every 6 months thereafter.
Respirators should not be loosened or removed in work situations where their use is
required.
B. Protective clothing: You are required to
wear protective clothing in work areas where
asbestos fiber concentrations exceed the permissible exposure limit.
IV. Disposal Procedures and Cleanup
A. Wastes that are generated by processes
where asbestos is present include:
1. Empty asbestos shipping containers.
2. Process wastes such as cuttings, trimmings, or reject material.
3. Housekeeping waste from sweeping or
vacuuming.
4. Asbestos fireproofing or insulating material that is removed from buildings.
5. Building products that contain asbestos
removed during building renovation or demolition.
6. Contaminated disposable protective
clothing.
B. Empty shipping bags can be flattened
under exhaust hoods and packed into airtight containers for disposal. Empty shipping drums are difficult to clean and should
be sealed.
C. Vacuum bags or disposable paper filters
should not be cleaned, but should be sprayed
with a fine water mist and placed into a labeled waste container.
D. Process waste and housekeeping waste
should be wetted with water or a mixture of
water and surfactant prior to packaging in
disposable containers.
E. Material containing asbestos that is removed from buildings must be disposed of in
leak-tight 6-mil thick plastic bags, plasticlined cardboard containers, or plastic-lined
metal containers. These wastes, which are
removed while wet, should be sealed in containers before they dry out to minimize the
release of asbestos fibers during handling.
II. Health Hazard Data
A. Asbestos can cause disabling respiratory
disease and various types of cancers if the fibers are inhaled. Inhaling or ingesting fibers
from contaminated clothing or skin can also
result in these diseases. The symptoms of
these diseases generally do not appear for 20
or more years after initial exposure.
B. Exposure to asbestos has been shown to
cause lung cancer, mesothelioma, and cancer
of the stomach and colon. Mesothelioma is a
rare cancer of the thin membrane lining of
the chest and abdomen. Symptoms of mesothelioma include shortness of breath, pain in
the walls of the chest, and/or abdominal
pain.
III. Respirators and Protective Clothing
V. Access to Information
A. Respirators: You are required to wear a
respirator when performing tasks that result
in asbestos exposure that exceeds the permissible exposure limit (PEL) of 0.1 f/cc.
These conditions can occur while your employer is in the process of installing engineering controls to reduce asbestos exposure,
or where engineering controls are not feasible to reduce asbestos exposure. Air-purifying respirators equipped with a high-efficiency particulate air (HEPA) filter can be
used where airborne asbestos fiber con-
A. Each year, your employer is required to
inform you of the information contained in
this standard and appendices for asbestos. In
addition, your employer must instruct you
in the proper work practices for handling
materials containing asbestos, and the correct use of protective equipment.
B. Your employer is required to determine
whether you are being exposed to asbestos.
You or your representative has the right to
observe employee measurements and to
56
record the results obtained. Your employer
is required to inform you of your exposure,
and, if you are exposed above the permissible
limit, he or she is required to inform you of
the actions that are being taken to reduce
your exposure to within the permissible
limit.
C. Your employer is required to keep
records of your exposures and medical examinations. These exposure records must be
kept for at least thirty (30) years. Medical
records must be kept for the period of your
employment plus thirty (30) years.
D. Your employer is required to release
your exposure and medical records to your
physician or designated representative upon
your written request.
§ 1910.1001
characteristic of mesothelioma include
shortness of breath, pain in the walls of the
chest, or abdominal pain. Mesothelioma has
a much longer latency period compared with
lung cancer (40 years versus 15–20 years), and
mesothelioma is therefore more likely to be
found among workers who were first exposed
to asbestos at an early age. Mesothelioma is
always fatal.
Asbestosis is pulmonary fibrosis caused by
the accumulation of asbestos fibers in the
lungs. Symptoms include shortness of
breath, coughing, fatigue, and vague feelings
of sickness. When the fibrosis worsens, shortness of breath occurs even at rest. The diagnosis of asbestosis is based on a history of
exposure to asbestos, the presence of characteristic radiologic changes, end-inspiratory crackles (rales), and other clinical features of fibrosing lung disease. Pleural
plaques and thickening are observed on Xrays taken during the early stages of the disease. Asbestosis is often a progressive disease even in the absence of continued exposure, although this appears to be a highly individualized characteristic. In severe cases,
death may be caused by respiratory or cardiac failure.
APPENDIX H TO § 1910.1001—MEDICAL
SURVEILLANCE GUIDELINES FOR ASBESTOS NON-MANDATORY
I. Route of Entry Inhalation, Ingestion
II. Toxicology
Clinical evidence of the adverse effects associated with exposure to asbestos is present
in the form of several well-conducted epidemiological studies of occupationally exposed
workers, family contacts of workers, and
persons living near asbestos mines. These
studies have shown a definite association between exposure to asbestos and an increased
incidence of lung cancer, pleural and peritoneal mesothelioma, gastrointestinal cancer, and asbestosis. The latter is a disabling
fibrotic lung disease that is caused only by
exposure to asbestos. Exposure to asbestos
has also been associated with an increased
incidence of esophageal, kidney, laryngeal,
pharyngeal, and buccal cavity cancers. As
with other known chronic occupational diseases, disease associated with asbestos generally appears about 20 years following the
first occurrence of exposure: There are no
known acute effects associated with exposure to asbestos.
Epidemiological studies indicate that the
risk of lung cancer among exposed workers
who smoke cigarettes is greatly increased
over the risk of lung cancer among non-exposed smokers or exposed nonsmokers. These
studies suggest that cessation of smoking
will reduce the risk of lung cancer for a person exposed to asbestos but will not reduce it
to the same level of risk as that existing for
an exposed worker who has never smoked.
IV. Surveillance and Preventive
Considerations
As noted above, exposure to asbestos has
been linked to an increased risk of lung cancer, mesothelioma, gastrointestinal cancer,
and asbestosis among occupationally exposed workers. Adequate screening tests to
determine an employee’s potential for developing serious chronic diseases, such as cancer, from exposure to asbestos do not presently exist. However, some tests, particularly chest X-rays and pulmonary function
tests, may indicate that an employee has
been overexposed to asbestos increasing his
or her risk of developing exposure-related
chronic diseases. It is important for the physician to become familiar with the operating
conditions in which occupational exposure to
asbestos is likely to occur. This is particularly important in evaluating medical and
work histories and in conducting physical
examinations. When an active employee has
been identified as having been overexposed
to asbestos, measures taken by the employer
to eliminate or mitigate further exposure
should also lower the risk of serious longterm consequences.
The employer is required to institute a
medical surveillance program for all employees who are or will be exposed to asbestos at
or above the permissible exposure limit (0.1
fiber per cubic centimeter of air). All examinations and procedures must be performed
by or under the supervision of a licensed
physician, at a reasonable time and place,
and at no cost to the employee.
Although broad latitude is given to the
physician in prescribing specific tests to be
III. Signs and Symptoms of ExposureRelated Disease
The signs and symptoms of lung cancer or
gastrointestinal cancer induced by exposure
to asbestos are not unique, except that a
chest X-ray of an exposed patient with lung
cancer may show pleural plaques, pleural
calcification, or pleural fibrosis. Symptoms
57
§ 1910.1001
included in the medical surveillance program, OSHA requires inclusion of the following elements in the routine examination:
(i) Medical and work histories with special
emphasis directed to symptoms of the respiratory system, cardiovascular system, and
digestive tract.
(ii) Completion of the respiratory disease
questionnaire contained in Appendix D.
(iii) A physical examination including a
chest roentgenogram and pulmonary function test that includes measurement of the
employee’s forced vital capacity (FVC) and
forced expiratory volume at one second
(FEV1).
(iv) Any laboratory or other test that the
examining physician deems by sound medical practice to be necessary.
The employer is required to make the prescribed tests available at least annually to
those employees covered; more often than
specified if recommended by the examining
physician; and upon termination of employment.
The employer is required to provide the
physician with the following information: A
copy of this standard and appendices; a description of the mployee’s duties as they relate to asbestos exposure; the employee’s
representative level of exposure to asbestos;
a description of any personal protective and
respiratory equipment used; and information
from previous medical examinations of the
affected employee that is not otherwise
available to the physician. Making this information available to the physician will aid
in the evaluation of the employee’s health in
relation to assigned duties and fitness to
wear personal protective equipment, if required.
The employer is required to obtain a written opinion from the examining physician
containing the results of the medical examination; the physician’s opinion as to whether the employee has any detected medical
conditions that would place the employee at
an increased risk of exposure-related disease;
any recommended limitations on the employee or on the use of personal protective
equipment; and a statement that the employee has been informed by the physician of
the results of the medical examination and
of any medical conditions related to asbestos
exposure that require further explanation or
treatment. This written opinion must not reveal specific findings or diagnoses unrelated
to exposure to asbestos, and a copy of the
opinion must be provided to the affected employee.
1. The National Cancer Institute operates a
toll-free Cancer Information Service (CIS)
with trained personnel to help you. Call 1–
800–4–CANCER* to reach the CIS office serving your area, or write: Office of Cancer
Communications, National Cancer Institute,
National Institutes of Health, Building 31,
Room 10A24, Bethesda, Maryland 20892.
2. American Cancer Society, 3340 Peachtree
Road, NE., Atlanta, Georgia 30062, (404) 320–
3333.
The American Cancer Society (ACS) is a
voluntary organization composed of 58 divisions and 3,100 local units. Through ‘‘The
Great American Smokeout’’ in November,
the annual Cancer Crusade in April, and numerous educational materials, ACS helps
people learn about the health hazards of
smoking and become successful ex-smokers.
3. American Heart Association, 7320 Greenville Avenue, Dallas, Texas 75231, (214) 750–
5300.
The American Heart Association (AHA) is
a voluntary organization with 130,000 members (physicians, scientists, and laypersons)
in 55 state and regional groups. AHA produces a variety of publications and audiovisual materials about the effects of smoking on the heart. AHA also has developed a
guidebook for incorporating a weight-control
component into smoking cessation programs.
4. American Lung Association, 1740 Broadway, New York, New York 10019, (212) 245–
8000.
A voluntary organization of 7,500 members
(physicians, nurses, and laypersons), the
American Lung Association (ALA) conducts
numerous public information programs
about the health effect of smoking. ALA has
59 state and 85 local units. The organization
actively supports legislation and information campaigns for non-smokers’ rights and
provides help for smokers who want to quit,
for example, through ‘‘Freedom From Smoking,’’ a self-help smoking cessation program.
5. Office on Smoking and Health, U.S. Department of Health and, Human Services,
5600 Fishers Lane, Park Building, Room 110,
Rockville, Maryland 20857.
The Office on Smoking and Health (OSH) is
the Department of Health and Human Services’ lead agency in smoking control. OSH
has sponsored distribution of publications on
smoking-realted topics, such as free flyers on
relapse after initial quitting, helping a
friend or family member quit smoking, the
health hazards of smoking, and the effects of
parental smoking on teenagers.
*In Hawaii, on Oahu call 524–1234 (call collect from neighboring islands),
Spanish-speaking staff members are available during daytime hours to callers from
the following areas: California, Florida,
Georgia, Illinois, New Jersey (area code 210),
New York, and Texas. Consult your local
APPENDIX I TO § 1910.1001—SMOKING CESSATION PROGRAM INFORMATION FOR
ASBESTOS—NON-MANDATORY
The following organizations provide smoking cessation information and program material.
58
§ 1910.1001
Brucite: A sheet mineral with the composition Mg(OH)2.
Central Stop Dispersion Staining (microscope):
This is a dark field microscope technique
that images particles using only light refracted by the particle, excluding light that
travels through the particle unrefracted.
This is usually accomplished with a McCrone
objective or other arrangement which places
a circular stop with apparent aperture equal
to the objective aperture in the back focal
plane of the microscope.
Cleavage Fragments: Mineral particles
formed by the comminution of minerals, especially those characterized by relatively
parallel sides and moderate aspect ratio.
Differential Counting: The term applied to
the practice of excluding certain kinds of fibers from a phase contrast asbestos count
because they are not asbestos.
Fiber: A particle longer than or equal to 5
µ m with a length to width ratio greater
than or equal to 3:1. This may include cleavage fragments. (see section 3.5 of this appendix).
Phase Contrast: Contrast obtained in the
microscope by causing light scattered by
small particles to destructively interfere
with unscattered light, thereby enhancing
the visibility of very small particles and particles with very low intrinsic contrast.
Phase Contrast Microscope: A microscope
configured with a phase mask pair to create
phase contrast. The technique which uses
this is called Phase Contrast Microscopy
(PCM).
Phase-Polar Analysis: This is the use of polarized light in a phase contrast microscope.
It is used to see the same size fibers that are
visible in air filter analysis. Although fibers
finer than 1 µ m are visible, analysis of these
is inferred from analysis of larger bundles
that are usually present.
Phase-Polar Microscope: The phase-polar
microscope is a phase contrast microscope
which has an analyzer, a polarizer, a first
order red plate and a rotating phase condenser all in place so that the polarized light
image is enhanced by phase contrast.
Sealing Encapsulant: This is a product
which can be applied, preferably by spraying,
onto an asbestos surface which will seal the
surface so that fibers cannot be released.
Serpentine: A mineral family consisting of
minerals with the general composition
Mg3(Si2O5(OH)4 having the magnesium in
brucite layer over a silicate layer. Minerals
important in asbestos analysis included in
this
family
are
chrysotile,
lizardite,
antigorite.
telephone directory for listings of local chapters.
APPENDIX J TO § 1910.1001—POLARIZED
LIGHT MICROSCOPY OF ASBESTOS—
NON-MANDATORY
Method number: ID–191
Matrix: Bulk
Collection Procedure
Collect approximately 1 to 2 grams of each
type of material and place into separate 20
mL scintillation vials.
Analytical Procedure
A portion of each separate phase is analyzed by gross examination, phase-polar examination, and central stop dispersion microscopy.
by USDOL–OSHA. Similar products from
other sources may be substituted.
1. Introduction
This method describes the collection and
analysis of asbestos bulk materials by light
microscopy techniques including phasepolar illumination and central-stop dispersion microscopy. Some terms unique to asbestos analysis are defined below:
Amphibole: A family of minerals whose
crystals are formed by long, thin units which
have two thin ribbons of double chain silicate with a brucite ribbon in between. The
shape of each unit is similar to an ‘‘I beam’’.
Minerals important in asbestos analysis include cummingtonite-grunerite, crocidolite,
tremolite-actinolite and anthophyllite.
Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile,
cummingtonite-grunerite asbestos (amosite),
anthophyllite asbestos, tremolite asbestos,
crocidolite, actinolite asbestos and any of
these minerals which have been chemically
treated or altered. The precise chemical formulation of each species varies with the location from which it was mined. Nominal
compositions are listed:
Chrysotile...............................Mg3 Si2 O5(OH)4
Crocidolite (Riebeckite asbestos) ....Na2 Fe32∂
Fe23∂ Si8 O22(OH)2
Cummingtonite-Grunerite
asbestos
(Amosite) .................(Mg,Fe)7 Si8 O22(OH)2
Tremolite-Actinolite asbestos .....Ca2(Mg,Fe)5
Si8 O22(OH)2
Anthophyllite asbestos ................(Mg,Fe)7 Si8
O22(OH)2
Asbestos Fiber: A fiber of asbestos meeting
the criteria for a fiber. (See section 3.5.)
Aspect Ratio: The ratio of the length of a
fiber to its diameter usually defined as
‘‘length : width’’, e.g. 3:1.
1.1. History
Light microscopy has been used for well
over 100 years for the determination of mineral species. This analysis is carried out
using specialized polarizing microscopes as
59
§ 1910.1001
than 1 µ m can adequately be defined in the
light microscope. The light microscope remains as the best instrument for the determination of mineral type. This is because
the minerals under investigation were first
described analytically with the light microscope. It is inexpensive and gives positive
identification for most samples analyzed.
Further, when optical techniques are inadequate, there is ample indication that alternative techniques should be used for complete identification of the sample.
well as bright field microscopes. The identification of minerals is an on-going process
with many new minerals described each
year. The first recorded use of asbestos was
in Finland about 2500 B.C. where the material was used in the mud wattle for the wooden huts the people lived in as well as
strengthening for pottery. Adverse health aspects of the mineral were noted nearly 2000
years ago when Pliny the Younger wrote
about the poor health of slaves in the asbestos mines. Although known to be injurious
for centuries, the first modern references to
its toxicity were by the British Labor
Inspectorate when it banned asbestos dust
from the workplace in 1898. Asbestosis cases
were described in the literature after the
turn of the century. Cancer was first suspected in the mid 1930’s and a causal link to
mesothelioma was made in 1965. Because of
the public concern for worker and public
safety with the use of this material, several
different types of analysis were applied to
the determination of asbestos content. Light
microscopy requires a great deal of experience and craft. Attempts were made to apply
less subjective methods to the analysis. Xray diffraction was partially successful in
determining the mineral types but was unable to separate out the fibrous portions
from the non-fibrous portions. Also, the minimum detection limit for asbestos analysis
by X-ray diffraction (XRD) is about 1%. Differential Thermal Analysis (DTA) was no
more successful. These provide useful corroborating information when the presence of
asbestos has been shown by microscopy;
however, neither can determine the difference between fibrous and non-fibrous minerals when both habits are present. The same
is true of Infrared Absorption (IR).
When electron microscopy was applied to
asbestos analysis, hundreds of fibers were
discovered present too small to be visible in
any light microscope. There are two different types of electron microscope used for
asbestos analysis: Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Scanning Electron Microscopy is useful in identifying minerals. The
SEM can provide two of the three pieces of
information required to identify fibers by
electron microscopy: morphology and chemistry. The third is structure as determined
by Selected Area Electron Diffraction—
SAED which is performed in the TEM. Although the resolution of the SEM is sufficient for very fine fibers to be seen, accuracy
of chemical analysis that can be performed
on the fibers varies with fiber diameter in fibers of less than 0.2 µ m diameter. The TEM
is a powerful tool to identify fibers too small
to be resolved by light microscopy and
should be used in conjunction with this
method when necessary. The TEM can provide all three pieces of information required
for fiber identification. Most fibers thicker
1.2. Principle
Minerals consist of atoms that may be arranged in random order or in a regular arrangement. Amorphous materials have
atoms in random order while crystalline materials have long range order. Many materials are transparent to light, at least for
small particles or for thin sections. The
properties of these materials can be investigated by the effect that the material has
on light passing through it. The six asbestos
minerals are all crystalline with particular
properties that have been identified and cataloged. These six minerals are anisotropic.
They have a regular array of atoms, but the
arrangement is not the same in all directions. Each major direction of the crystal
presents a different regularity. Light photons travelling in each of these main directions will encounter different electrical
neighborhoods, affecting the path and time
of travel. The techniques outlined in this
method use the fact that light traveling
through fibers or crystals in different directions will behave differently, but predictably. The behavior of the light as it travels
through a crystal can be measured and compared with known or determined values to
identify the mineral species. Usually, Polarized Light Microscopy (PLM) is performed
with strain-free objectives on a bright-field
microscope platform. This would limit the
resolution of the microscope to about 0.4 µm.
Because OSHA requires the counting and
identification of fibers visible in phase contrast, the phase contrast platform is used to
visualize the fibers with the polarizing elements added into the light path. Polarized
light methods cannot identify fibers finer
than about 1 µm in diameter even though
they are visible. The finest fibers are usually
identified by inference from the presence of
larger, identifiable fiber bundles. When fibers
are present, but not identifiable by light microscopy, use either SEM or TEM to determine the fiber identity.
1.3. Advantages and Disadvantages
The advantages of light microcopy are:
(a) Basic identification of the materials
was first performed by light microscopy and
gross analysis. This provides a large base of
60
published information against which to
check analysis and analytical technique.
(b) The analysis is specific to fibers. The
minerals present can exist in asbestiform, fibrous, prismatic, or massive varieties all at
the same time. Therefore, bulk methods of
analysis such as X-ray diffraction, IR analysis, DTA, etc. are inappropriate where the
material is not known to be fibrous.
(c) The analysis is quick, requires little
preparation time, and can be performed onsite if a suitably equipped microscope is
available.
The disadvantages are:
(a) Even using phase-polar illumination,
not all the fibers present may be seen. This
is a problem for very low asbestos concentrations where agglomerations or large bundles
of fibers may not be present to allow identification by inference.
(b) The method requires a great degree of
sophistication
on
the
part
of
the
microscopist. An analyst is only as useful as
his mental catalog of images. Therefore, a
microscopist’s accuracy is enhanced by experience. The mineralogical training of the analyst is very important. It is the basis on
which subjective decisions are made.
(c) The method uses only a tiny amount of
material for analysis. This may lead to sampling bias and false results (high or low).
This is especially true if the sample is severely inhomogeneous.
(d) Fibers may be bound in a matrix and
not distinguishable as fibers so identification cannot be made.
§ 1910.1001
amount is usually more than a few percent.
An analyst’s results can be ‘‘calibrated’’
against the known amounts added by the
manufacturer. For geological samples, the
degree of homogeneity affects the precision.
1.4.3. The performance of the method is analyst dependent. The analyst must choose
carefully and not necessarily randomly the
portions for analysis to assure that detection
of asbestos occurs when it is present. For
this reason, the analyst must have adequate
training in sample preparation, and experience in the location and identification of asbestos in samples. This is usually accomplished through substantial on-the-job training as well as formal education in mineralogy and microscopy.
1.5. Interferences
Any material which is long, thin, and
small enough to be viewed under the microscope can be considered an interference for
asbestos. There are literally hundreds of
interferences in workplaces. The techniques
described in this method are normally sufficient to eliminate the interferences. An analyst’s success in eliminating the interferences depends on proper training.
Asbestos minerals belong to two mineral
families: the serpentines and the amphiboles.
In the serpentine family, the only common
fibrous mineral is chrysotile. Occasionally,
the mineral antigorite occurs in a fibril
habit with morphology similar to the
amphiboles. The amphibole minerals consist
of a score of different minerals of which only
five are regulated by federal standard:
amosite, crocidolite, anthophyllite asbestos,
tremolite asbestos and actinolite asbestos.
These are the only amphibole minerals that
have been commercially exploited for their
fibrous properties; however, the rest can and
do occur occasionally in asbestiform habit.
In addition to the related mineral interferences, other minerals common in building
material may present a problem for some
microscopists: gypsum, anhydrite, brucite,
quartz fibers, talc fibers or ribbons, wollastonite, perlite, attapulgite, etc. Other fibrous materials commonly present in workplaces are: fiberglass, mineral wool, ceramic
wool, refractory ceramic fibers, kevlar,
nomex, synthetic fibers, graphite or carbon
fibers, cellulose (paper or wood) fibers, metal
fibers, etc.
Matrix embedding material can sometimes
be a negative interference. The analyst may
not be able to easily extract the fibers from
the matrix in order to use the method.
Where possible, remove the matrix before
the analysis, taking careful note of the loss
of weight. Some common matrix materials
are: vinyl, rubber, tar, paint, plant fiber, cement, and epoxy. A further negative interference is that the asbestos fibers themselves
may be either too small to be seen in Phase
contrast Microscopy (PCM) or of a very low
1.4. Method Performance
1.4.1. This method can be used for determination of asbestos content from 0 to 100%
asbestos. The detection limit has not been
adequately determined, although for selected
samples, the limit is very low, depending on
the number of particles examined. For mostly homogeneous, finely divided samples, with
no difficult fibrous interferences, the detection limit is below 1%. For inhomogeneous
samples (most samples), the detection limit
remains undefined. NIST has conducted proficiency testing of laboratories on a national
scale. Although each round is reported statistically with an average, control limits,
etc., the results indicate a difficulty in establishing precision especially in the low
concentration range. It is suspected that
there is significant bias in the low range especially near 1%. EPA tried to remedy this
by requiring a mandatory point counting
scheme for samples less than 10%. The point
counting procedure is tedious, and may introduce significant biases of its own. It has
not been incorporated into this method.
1.4.2. The precision and accuracy of the
quantitation tests performed in this method
are unknown. Concentrations are easier to
determine in commercial products where asbestos was deliberately added because the
61
§ 1910.1001
2. Sampling Procedure
fibrous quality, having the appearance of
plant fibers. The analyst’s ability to deal
with these materials increases with experience.
2.1. Equipment for Sampling
(a)
(b)
(c)
(d)
1.6. Uses and Occupational Exposure
Asbestos is ubiquitous in the environment.
More than 40% of the land area of the United
States is composed of minerals which may
contain asbestos. Fortunately, the actual
formation of great amounts of asbestos is
relatively rare. Nonetheless, there are locations in which environmental exposure can
be severe such as in the Serpentine Hills of
California.
There are thousands of uses for asbestos in
industry and the home. Asbestos abatement
workers are the most current segment of the
population to have occupational exposure to
great amounts of asbestos. If the material is
undisturbed, there is no exposure. Exposure
occurs when the asbestos-containing material is abraded or otherwise disturbed during
maintenance operations or some other activity. Approximately 95% of the asbestos in
place in the United States is chrysotile.
Amosite and crocidolite make up nearly
all
the
difference.
Tremolite
and
anthophyllite make up a very small percentage. Tremolite is found in extremely small
amounts in certain chrysotile deposits. Actinolite exposure is probably greatest from
environmental sources, but has been identified in vermiculite containing, sprayed-on
insulating materials which may have been
certified as asbestos-free.
Tube or cork borer sampling device
Knife
20 mL scintillation vial or similar vial
Sealing encapsulant
Asbestos is a known carcinogen. Take care
when sampling. While in an asbestos-containing atmosphere, a properly selected and
fit-tested respirator should be worn. Take
samples in a manner to cause the least
amount of dust. Follow these general guidelines:
(a) Do not make unnecessary dust.
(b) Take only a small amount (1 to 2 g).
(c) Tightly close the sample container.
(d) Use encapsulant to seal the spot where
the sample was taken, if necessary.
2.3. Sampling Procedure
Samples of any suspect material should be
taken from an inconspicuous place. Where
the material is to remain, seal the sampling
wound with an encapsulant to eliminate the
potential for exposure from the sample site.
Microscopy requires only a few milligrams of
material. The amount that will fill a 20 mL
scintillation vial is more than adequate. Be
sure to collect samples from all layers and
phases of material. If possible, make separate samples of each different phase of the
material. This will aid in determining the
actual hazard. DO NOT USE ENVELOPES,
PLASTIC OR PAPER BAGS OF ANY KIND TO
COLLECT SAMPLES. The use of plastic bags
presents a contamination hazard to laboratory personnel and to other samples. When
these containers are opened, a bellows effect
blows fibers out of the container onto everything, including the person opening the container.
If a cork-borer type sampler is available,
push the tube through the material all the
way, so that all layers of material are sampled. Some samplers are intended to be disposable. These should be capped and sent to
the laboratory. If a non-disposable cork
borer is used, empty the contents into a scintillation vial and send to the laboratory.
Vigorously and completely clean the cork
borer between samples.
1.7. Physical and Chemical Properties
The nominal chemical compositions for
the asbestos minerals were given in Section
1. Compared to cleavage fragments of the
same minerals, asbestiform fibers possess a
high tensile strength along the fiber axis.
They are chemically inert, non- combustible,
and heat resistant. Except for chrysotile,
they are insoluble in Hydrochloric acid
(HCl). Chrysotile is slightly soluble in HCl.
Asbestos has high electrical resistance and
good sound absorbing characteristics. It can
be woven into cables, fabrics or other textiles, or matted into papers, felts, and mats.
1.8. Toxicology (This Section is for Information Only and Should Not Be Taken as
OSHA Policy)
2.4 Shipment
Possible physiologic results of respiratory
exposure to asbestos are mesothelioma of the
pleura or peritoneum, interstitial fibrosis,
asbestosis, pneumoconiosis, or respiratory
cancer. The possible consequences of asbestos exposure are detailed in the NIOSH Criteria Document or in the OSHA Asbestos
Standards 29 CFR 1910.1001 and 29 CFR
1926.1101 and 29 CFR 1915.1001.
Samples packed in glass vials must not
touch or they might break in shipment.
(a) Seal the samples with a sample seal
over the end to guard against tampering and
to identify the sample.
(b) Package the bulk samples in separate
packages from the air samples. They may
cross-contaminate each other and will invalidate the results of the air samples.
62
(c) Include identifying paperwork with the
samples, but not in contact with the suspected asbestos.
(d) To maintain sample accountability,
ship the samples by certified mail, overnight
express, or hand carry them to the laboratory.
§ 1910.1001
(h) High dispersion index of refraction oils
(Special for dispersion staining.)
n = 1.550
n = 1.585
n = 1.590
n = 1.605
n = 1.620
n = 1.670
n = 1.680
n = 1.690
(i) A set of index of refraction oils from
about n=1.350 to n=2.000 in n=0.005 increments. (Standard for Becke line analysis.)
(j) Glass slides with painted or frosted ends
1×3 inches 1mm thick, precleaned.
(k) Cover Slips 22×22 mm, #11⁄2
(l) Paper clips or dissection needles
(m) Hand grinder
(n) Scalpel with both #10 and #11 blades
(o) 0.1 molar HCl
(p) Decalcifying solution (Baxter Scientific
Products) Ethylenediaminetetraacetic Acid,
3. Analysis
The analysis of asbestos samples can be divided into two major parts: sample preparation and microscopy. Because of the different
asbestos uses that may be encountered by
the analyst, each sample may need different
preparation steps. The choices are outlined
below. There are several different tests that
are performed to identify the asbestos species and determine the percentage. They will
be explained below.
3.1. Safety
(a) Do not create unnecessary dust. Handle
the samples in HEPA-filter equipped hoods.
If samples are received in bags, envelopes or
other inappropriate container, open them
only in a hood having a face velocity at or
greater than 100 fpm. Transfer a small
amount to a scintillation vial and only handle the smaller amount.
(b) Open samples in a hood, never in the
open lab area.
(c) Index of refraction oils can be toxic.
Take care not to get this material on the
skin. Wash immediately with soap and water
if this happens.
(d) Samples that have been heated in the
muffle furnace or the drying oven may be
hot. Handle them with tongs until they are
cool enough to handle.
(e) Some of the solvents used, such as THF
(tetrahydrofuran), are toxic and should only
be handled in an appropriate fume hood and
according to instructions given in the Material Safety Data Sheet (MSDS).
Tetrasodium ..........................................0.7 g/l
Sodium Potassium Tartrate .........8.0 mg/liter
Hydrochloric Acid ..........................99.2 g/liter
Sodium Tartrate.............................0.14 g/liter
(q) Tetrahydrofuran (THF)
(r) Hotplate capable of 60 °C
(s) Balance
(t) Hacksaw blade
(u) Ruby mortar and pestle
3.3. Sample Pre-Preparation
Sample preparation begins with pre-preparation which may include chemical reduction of the matrix, heating the sample to
dryness or heating in the muffle furnace. The
end result is a sample which has been reduced to a powder that is sufficiently fine to
fit under the cover slip. Analyze different
phases of samples separately, e.g., tile and
the tile mastic should be analyzed separately
as the mastic may contain asbestos while
the tile may not.
3.2. Equipment
(a) Wet samples
(a) Phase contrast microscope with 10x, 16x
and 40x objectives, 10x wide-field eyepieces,
G–22 Walton-Beckett graticule, Whipple
disk, polarizer, analyzer and first order red
or gypsum plate, 100 Watt illuminator, rotating position condenser with oversize phase
rings, central stop dispersion objective,
Kohler illumination and a rotating mechanical stage.
(b) Stereo microscope with reflected light
illumination, transmitted light illumination, polarizer, analyzer and first order red
or gypsum plate, and rotating stage.
(c) Negative pressure hood for the stereo
microscope
(d) Muffle furnace capable of 600 °C
(e) Drying oven capable of 50—150 °C
(f) Aluminum specimen pans
(g) Tongs for handling samples in the furnace
Samples with a high water content will not
give the proper dispersion colors and must be
dried prior to sample mounting. Remove the
lid of the scintillation vial, place the bottle
in the drying oven and heat at 100 °C to dryness (usually about 2 h). Samples which are
not submitted to the lab in glass must be removed and placed in glass vials or aluminum
weighing pans before placing them in the
drying oven.
(b) Samples With Organic Interference—Muffle
Furnace
These may include samples with tar as a
matrix, vinyl asbestos tile, or any other organic that can be reduced by heating. Remove the sample from the vial and weigh in
a balance to determine the weight of the submitted portion. Place the sample in a muffle
63
§ 1910.1001
furnace at 500 °C for 1 to 2 h or until all obvious organic material has been removed. Retrieve, cool and weigh again to determine
the weight loss on ignition. This is necessary
to determine the asbestos content of the submitted sample, because the analyst will be
looking at a reduced sample.
NOTE: Heating above 600 °C will cause the
sample to undergo a structural change
which, given sufficient time, will convert the
chrysotile to forsterite. Heating even at
lower temperatures for 1 to 2 h may have a
measurable effect on the optical properties
of the minerals. If the analyst is unsure of
what to expect, a sample of standard asbestos should be heated to the same temperature for the same length of time so that it
can be examined for the proper interpretation.
shock occurs. (Freezer mills can completely
destroy the observable crystallinity of asbestos and should not be used). For some samples, a portion of material can be shaved off
with a scalpel, ground off with a hand grinder or hack saw blade.
The preparation tools should either be disposable or cleaned thoroughly. Use vigorous
scrubbing to loosen the fibers during the
washing. Rinse the implements with copious
amounts of water and air-dry in a dust-free
environment.
(2) If the sample is powder or has been reduced as in (1) above, it is ready to mount.
Place a glass slide on a piece of optical tissue and write the identification on the painted or frosted end. Place two drops of index of
refraction medium n=1.550 on the slide. (The
medium n=1.550 is chosen because it is the
matching index for chrysotile. Dip the end of
a clean paper-clip or dissecting needle into
the droplet of refraction medium on the slide
to moisten it. Then dip the probe into the
powder sample. Transfer what sticks on the
probe to the slide. The material on the end of
the probe should have a diameter of about 3
mm for a good mount. If the material is very
fine, less sample may be appropriate. For
non-powder samples such as fiber mats, forceps should be used to transfer a small
amount of material to the slide. Stir the material in the medium on the slide, spreading
it out and making the preparation as uniform as possible. Place a cover-slip on the
preparation by gently lowering onto the
slide and allowing it to fall ‘‘trapdoor’’ fashion on the preparation to push out any bubbles. Press gently on the cover slip to even
out the distribution of particulate on the
slide. If there is insufficient mounting oil on
the slide, one or two drops may be placed
near the edge of the coverslip on the slide.
Capillary action will draw the necessary
amount of liquid into the preparation. Remove excess oil with the point of a laboratory wiper.
Treat at least two different areas of each
phase in this fashion. Choose representative
areas of the sample. It may be useful to select particular areas or fibers for analysis.
This is useful to identify asbestos in severely
inhomogeneous samples.
When it is determined that amphiboles
may be present, repeat the above process
using the appropriate high-dispersion oils
until an identification is made or all six asbestos minerals have been ruled out. Note
that percent determination must be done in
the index medium 1.550 because amphiboles
tend to disappear in their matching mediums.
(c) Samples With Organic Interference—THF
Vinyl asbestos tile is the most common
material treated with this solvent, although,
substances containing tar will sometimes
yield to this treatment. Select a portion of
the material and then grind it up if possible.
Weigh the sample and place it in a test tube.
Add sufficient THF to dissolve the organic
matrix. This is usually about 4 to 5 mL. Remember, THF is highly flammable. Filter the
remaining material through a tared silver
membrane, dry and weigh to determine how
much is left after the solvent extraction.
Further process the sample to remove carbonate or mount directly.
(d) Samples With Carbonate Interference
Carbonate material is often found on fibers
and sometimes must be removed in order to
perform dispersion microscopy. Weigh out a
portion of the material and place it in a test
tube. Add a sufficient amount of 0.1 M HCl or
decalcifying solution in the tube to react all
the carbonate as evidenced by gas formation;
i.e., when the gas bubbles stop, add a little
more solution. If no more gas forms, the reaction is complete. Filter the material out
through a tared silver membrane, dry and
weigh to determine the weight lost.
3.4. Sample Preparation
Samples must be prepared so that accurate
determination can be made of the asbestos
type and amount present. The following
steps are carried out in the low-flow hood (a
low-flow hood has less than 50 fpm flow):
(1) If the sample has large lumps, is hard,
or cannot be made to lie under a cover slip,
the grain size must be reduced. Place a small
amount between two slides and grind the
material between them or grind a small
amount in a clean mortar and pestle. The
choice of whether to use an alumina, ruby,
or diamond mortar depends on the hardness
of the material. Impact damage can alter the
asbestos mineral if too much mechanical
3.5. Analytical Procedure
NOTE: This method presumes some knowledge of mineralogy and optical petrography.
The analysis consists of three parts: The
determination of whether there is asbestos
64
present, what type is present and the determination of how much is present. The general flow of the analysis is:
(1) Gross examination.
(2) Examination under polarized light on
the stereo microscope.
(3) Examination by phase-polar illumination on the compound phase microscope.
(4) Determination of species by dispersion
stain. Examination by Becke line analysis
may also be used; however, this is usually
§ 1910.1001
more cumbersome for asbestos determination.
(5) Difficult samples may need to be analyzed by SEM or TEM, or the results from
those techniques combined with light microscopy for a definitive identification. Identification of a particle as asbestos requires
that it be asbestiform. Description of particles should follow the suggestion of Campbell. (Figure 1)
65
§ 1910.1001
have a very high tensile strength as demonstrated by bending without breaking. Asbestos fibers exist in bundles that are easily
parted, show longitudinal fine structure and
may be tufted at the ends showing ‘‘bundle
of sticks’’ morphology. In the microscope
For the purpose of regulation, the mineral
must be one of the six minerals covered and
must be in the asbestos growth habit. Large
specimen samples of asbestos generally have
the gross appearance of wood. Fibers are easily parted from it. Asbestos fibers are very
long compared with their widths. The fibers
66
some of these properties may not be observable. Amphiboles do not always show striations along their length even when they are
asbestos. Neither will they always show tufting. They generally do not show a curved nature except for very long fibers. Asbestos and
asbestiform minerals are usually characterized in groups by extremely high aspect ratios (greater than 100:1). While aspect ratio
analysis is useful for characterizing populations of fibers, it cannot be used to identify
individual fibers of intermediate to short aspect ratio. Observation of many fibers is
often necessary to determine whether a sample consists of ‘‘cleavage fragments’’ or of asbestos fibers.
Most cleavage fragments of the asbestos
minerals are easily distinguishable from true
asbestos fibers. This is because true cleavage
fragments usually have larger diameters
than 1 µm. Internal structure of particles
larger than this usually shows them to have
no internal fibrillar structure. In addition,
cleavage fragments of the monoclinic
amphiboles show inclined extinction under
crossed polars with no compensator. Asbestos fibers usually show extinction at zero degrees or ambiguous extinction if any at all.
Morphologically, the larger cleavage fragments are obvious by their blunt or stepped
ends showing prismatic habit. Also, they
tend to be acicular rather than filiform.
Where the particles are less than 1 µm in
diameter and have an aspect ratio greater
than or equal to 3:1, it is recommended that
the sample be analyzed by SEM or TEM if
there is any question whether the fibers are
cleavage fragments or asbestiform particles.
Care must be taken when analyzing by
electron microscopy because the interferences are different from those in light microscopy and may structurally be very similar to asbestos. The classic interference is
between anthophyllite and biopyribole or intermediate fiber. Use the same morphological clues for electron microscopy as are
used for light microscopy, e.g. fibril splitting, internal longitudinal striation, fraying,
curvature, etc.
(1) Gross examination:
Examine the sample, preferably in the
glass vial. Determine the presence of any obvious fibrous component. Estimate a percentage based on previous experience and
current observation. Determine whether any
pre- preparation is necessary. Determine the
number of phases present. This step may be
carried out or augmented by observation at
6 to 40× under a stereo microscope.
(2) After performing any necessary prepreparation, prepare slides of each phase as
described above. Two preparations of the
same phase in the same index medium can be
made side-by-side on the same glass for convenience. Examine with the polarizing stereo
microscope. Estimate the percentage of as-
§ 1910.1001
bestos based on the amount of birefringent
fiber present.
(3) Examine the slides on the phase-polar
microscopes at magnifications of 160 and
400×. Note the morphology of the fibers.
Long, thin, very straight fibers with little
curvature are indicative of fibers from the
amphibole family. Curved, wavy fibers are
usually indicative of chrysotile. Estimate
the percentage of asbestos on the phase-polar
microscope under conditions of crossed
polars and a gypsum plate. Fibers smaller
than 1.0 µm in thickness must be identified
by inference to the presence of larger, identifiable fibers and morphology. If no larger fibers are visible, electron microscopy should
be performed. At this point, only a tentative
identification can be made. Full identification must be made with dispersion microscopy. Details of the tests are included in the
appendices.
(4) Once fibers have been determined to be
present, they must be identified. Adjust the
microscope for dispersion mode and observe
the fibers. The microscope has a rotating
stage, one polarizing element, and a system
for generating dark-field dispersion microscopy (see Section 4.6. of this appendix). Align
a fiber with its length parallel to the polarizer and note the color of the Becke lines.
Rotate the stage to bring the fiber length
perpendicular to the polarizer and note the
color. Repeat this process for every fiber or
fiber bundle examined. The colors must be
consistent with the colors generated by
standard asbestos reference materials for a
positive
identification.
In
n=1.550,
amphiboles will generally show a yellow to
straw-yellow color indicating that the fiber
indices of refraction are higher than the liquid. If long, thin fibers are noted and the colors are yellow, prepare further slides as
above in the suggested matching liquids listed below:
Type of asbestos
Chrysotile ...............................
Amosite ..................................
Crocidolite ..............................
Anthophyllite ..........................
Tremolite ................................
Actinolite ................................
Index of refraction
n=1.550.
n=1.670 r 1.680.
n=1.690.
n=1.605 nd 1.620.
n=1.605 and 1.620.
n=1.620.
Where more than one liquid is suggested,
the first is preferred; however, in some cases
this liquid will not give good dispersion
color. Take care to avoid interferences in the
other liquid; e.g., wollastonite in n=1.620 will
give the same colors as tremolite. In n=1.605
wollastonite will appear yellow in all directions. Wollastonite may be determined under
crossed polars as it will change from blue to
yellow as it is rotated along its fiber axis by
tapping on the cover slip. Asbestos minerals
will not change in this way.
Determination of the angle of extinction
may, when present, aid in the determination
67
§ 1910.1001
Step 3. Microvisual estimation determines
that 5% of the sample is chrysotile asbestos.
of anthophyllite from tremolite. True asbestos fibers usually have 0° extinction or ambiguous extinction, while cleavage fragments
have more definite extinction.
Continue analysis until both preparations
have been examined and all present species
of asbestos are identified. If there are no fibers present, or there is less than 0.1%
present, end the analysis with the minimum
number of slides (2).
(5) Some fibers have a coating on them
which makes dispersion microscopy very difficult or impossible. Becke line analysis or
electron microscopy may be performed in
those cases. Determine the percentage by
light microscopy. TEM analysis tends to
overestimate the actual percentage present.
(6) Percentage determination is an estimate of occluded area, tempered by gross observation. Gross observation information is
used to make sure that the high magnification microscopy does not greatly over- or
underestimate the amount of fiber present.
This part of the analysis requires a great
deal of experience. Satisfactory models for
asbestos content analysis have not yet been
developed, although some models based on
metallurgical grain-size determination have
found some utility. Estimation is more easily handled in situations where the grain
sizes visible at about 160× are about the same
and the sample is relatively homogeneous.
View all of the area under the cover slip to
make the percentage determination. View
the fields while moving the stage, paying attention to the clumps of material. These are
not usually the best areas to perform dispersion microscopy because of the interference
from other materials. But, they are the areas
most likely to represent the accurate percentage in the sample. Small amounts of asbestos require slower scanning and more frequent analysis of individual fields.
Report the area occluded by asbestos as
the concentration. This estimate does not
generally take into consideration the difference in density of the different species
present in the sample. For most samples this
is adequate. Simulation studies with similar
materials must be carried out to apply
microvisual estimation for that purpose and
is beyond the scope of this procedure.
(7) Where successive concentrations have
been made by chemical or physical means,
the amount reported is the percentage of the
material in the ‘‘as submitted’’ or original
state. The percentage determined by microscopy is multiplied by the fractions remaining after pre-preparation steps to give the
percentage in the original sample. For example:
The reported result is:
R=(Microvisual
result
in
percent)×(Fraction remaining after step
2)×(Fraction remaining of original sample after step 1)
R=(5)×(.30)×(.60)=0.9%
(8) Report the percent and type of asbestos
present. For samples where asbestos was
identified, but is less than 1.0%, report ‘‘Asbestos present, less than 1.0%.’’ There must
have been at least two observed fibers or
fiber bundles in the two preparations to be
reported as present. For samples where asbestos was not seen, report as ‘‘None Detected.’’
4. Auxiliary Information
Because of the subjective nature of asbestos analysis, certain concepts and procedures
need to be discussed in more depth. This information will help the analyst understand
why some of the procedures are carried out
the way they are.
4.1. Light
Light is electromagnetic energy. It travels
from its source in packets called quanta. It
is instructive to consider light as a plane
wave. The light has a direction of travel.
Perpendicular to this and mutually perpendicular to each other, are two vector components. One is the magnetic vector and the
other is the electric vector. We shall only be
concerned with the electric vector. In this
description, the interaction of the vector and
the mineral will describe all the observable
phenomena. From a light source such a microscope illuminator, light travels in all different direction from the filament.
In any given direction away from the filament, the electric vector is perpendicular to
the direction of travel of a light ray. While
perpendicular, its orientation is random
about the travel axis. If the electric vectors
from all the light rays were lined up by passing the light through a filter that would only
let light rays with electric vectors oriented
in one direction pass, the light would then be
POLARIZED.
Polarized light interacts with matter in
the direction of the electric vector. This is
the polarization direction. Using this property it is possible to use polarized light to
probe different materials and identify them
by how they interact with light.
The speed of light in a vacuum is a constant at about 2.99×10 8 m/s. When light travels in different materials such as air, water,
minerals or oil, it does not travel at this
speed. It travels slower. This slowing is a
function of both the material through which
the light is traveling and the wavelength or
Step 1. 60% remains after heating at 550 °C
for 1 h. Step 2. 30% of the residue of step
1 remains after dissolution of carbonate
in 0.1 m HCl.
68
frequency of the light. In general, the more
dense the material, the slower the light travels. Also, generally, the higher the frequency, the slower the light will travel. The
ratio of the speed of light in a vacuum to
that in a material is called the index of refraction (n). It is usually measured at 589 nm
(the sodium D line). If white light (light containing all the visible wavelengths) travels
through a material, rays of longer wavelengths will travel faster than those of shorter wavelengths, this separation is called dispersion. Dispersion is used as an identifier of
materials as described in Section 4.6.
§ 1910.1001
They are called ‘‘length-slow’’. This orientation to fiber length is used to aid in the identification of asbestos.
4.3. Polarized Light Technique
Polarized light microscopy as described in
this section uses the phase-polar microscope
described in Section 3.2. A phase contrast
microscope is fitted with two polarizing elements, one below and one above the sample.
The polarizers have their polarization directions at right angles to each other. Depending on the tests performed, there may be a
compensator between these two polarizing
elements. Light emerging from a polarizing
element has its electric vector pointing in
the polarization direction of the element.
The light will not be subsequently transmitted through a second element set at a
right angle to the first element. Unless the
light is altered as it passes from one element
to the other, there is no transmission of
light.
4.2. Material Properties
Materials are either amorphous or crystalline. The difference between these two descriptions depends on the positions of the
atoms in them. The atoms in amorphous materials are randomly arranged with no long
range order. An example of an amorphous
material is glass. The atoms in crystalline
materials, on the other hand, are in regular
arrays and have long range order. Most of
the atoms can be found in highly predictable
locations. Examples of crystalline material
are salt, gold, and the asbestos minerals.
It is beyond the scope of this method to describe the different types of crystalline materials that can be found, or the full description of the classes into which they can fall.
However, some general crystallography is
provided below to give a foundation to the
procedures described.
With the exception of anthophyllite, all
the asbestos minerals belong to the
monoclinic crystal type. The unit cell is the
basic repeating unit of the crystal and for
monoclinic crystals can be described as having three unequal sides, two 90° angles and
one angle not equal to 90°. The orthorhombic
group, of which anthophyllite is a member
has three unequal sides and three 90° angles.
The unequal sides are a consequence of the
complexity of fitting the different atoms
into the unit cell. Although the atoms are in
a regular array, that array is not symmetrical in all directions. There is long range
order in the three major directions of the
crystal. However, the order is different in
each of the three directions. This has the effect that the index of refraction is different
in each of the three directions. Using polarized light, we can investigate the index of refraction in each of the directions and identify the mineral or material under investigation. The indices α, β, and γ are used to identify the lowest, middle, and highest index of
refraction respectively. The x direction, associated with α is called the fast axis. Conversely, the z direction is associated with γ
and is the slow direction. Crocidolite has α
along the fiber length making it ‘‘lengthfast’’. The remainder of the asbestos minerals have the γ axis along the fiber length.
4.4. Angle of Extinction
Crystals which have different crystal regularity in two or three main directions are
said to be anisotropic. They have a different
index of refraction in each of the main directions. When such a crystal is inserted between the crossed polars, the field of view is
no longer dark but shows the crystal in
color. The color depends on the properties of
the crystal. The light acts as if it travels
through the crystal along the optical axes. If
a crystal optical axis were lined up along one
of the polarizing directions (either the polarizer or the analyzer) the light would appear
to travel only in that direction, and it would
blink out or go dark. The difference in degrees between the fiber direction and the
angle at which it blinks out is called the
angle of extinction. When this angle can be
measured, it is useful in identifying the mineral. The procedure for measuring the angle
of extinction is to first identify the polarization direction in the microscope. A commercial alignment slide can be used to establish
the
polarization
directions
or
use
anthophyllite or another suitable mineral.
This mineral has a zero degree angle of extinction and will go dark to extinction as it
aligns with the polarization directions. When
a fiber of anthophyllite has gone to extinction, align the eyepiece reticle or graticule
with the fiber so that there is a visual cue as
to the direction of polarization in the field of
view. Tape or otherwise secure the eyepiece
in this position so it will not shift.
After the polarization direction has been
identified in the field of view, move the particle of interest to the center of the field of
view and align it with the polarization direction. For fibers, align the fiber along this direction. Note the angular reading of the rotating stage. Looking at the particle, rotate
69
§ 1910.1001
the stage until the fiber goes dark or ‘‘blinks
out’’. Again note the reading of the stage.
The difference in the first reading and the
second is an angle of extinction.
The angle measured may vary as the orientation of the fiber changes about its long
axis. Tables of mineralogical data usually report the maximum angle of extinction. Asbestos forming minerals, when they exhibit
an angle of extinction, usually do show an
angle of extinction close to the reported
maximum, or as appropriate depending on
the substitution chemistry.
the 530 nm wavelength color. This enhances
the red color and gives the background a
characteristic red to red-magenta color. If
this ‘‘full-wave’’ compensator is in place
when the asbestos preparation is inserted
into the light train, the colors seen on the fibers are quite different. Gypsum, like asbestos has a fast axis and a slow axis. When a
fiber is aligned with its fast axis in the same
direction as the fast axis of the gypsum
plate, the ray vibrating in the slow direction
is retarded by both the asbestos and the gypsum. This results in a higher retardation
than would be present for either of the two
minerals. The color seen is a second order
blue. When the fiber is rotated 90° using the
rotating stage, the slow direction of the fiber
is now aligned with the fast direction of the
gypsum and the fast direction of the fiber is
aligned with the slow direction of the gypsum. Thus, one ray vibrates faster in the fast
direction of the gypsum, and slower in the
slow direction of the fiber; the other ray will
vibrate slower in the slow direction of the
gypsum and faster in the fast direction of
the fiber. In this case, the effect is subtractive and the color seen is a first order yellow. As long as the fiber thickness does not
add appreciably to the color, the same basic
colors will be seen for all asbestos types except crocidolite. In crocidolite the colors
will be weaker, may be in the opposite directions, and will be altered by the blue absorption color natural to crocidolite. Hundreds of
other materials will give the same colors as
asbestos, and therefore, this test is not definitive for asbestos. The test is useful in discriminating against fiberglass or other
amorphous fibers such as some synthetic fibers. Certain synthetic fibers will show retardation colors different than asbestos;
however, there are some forms of polyethylene and aramid which will show morphology and retardation colors similar to asbestos minerals. This test must be supplemented with a positive identification test
when birefringent fibers are present which
can not be excluded by morphology. This
test is relatively ineffective for use on fibers
less than 1 µm in diameter. For positive confirmation TEM or SEM should be used if no
larger bundles or fibers are visible.
4.5. Crossed Polars with Compensator
When the optical axes of a crystal are not
lined up along one of the polarizing directions (either the polarizer or the analyzer)
part of the light travels along one axis and
part travels along the other visible axis. This
is characteristic of birefringent materials.
The color depends on the difference of the
two visible indices of refraction and the
thickness of the crystal. The maximum difference available is the difference between
the α and the γ axes. This maximum difference is usually tabulated as the
birefringence of the crystal.
For this test, align the fiber at 45° to the
polarization directions in order to maximize
the contribution to each of the optical axes.
The colors seen are called retardation colors.
They arise from the recombination of light
which has traveled through the two separate
directions of the crystal. One of the rays is
retarded behind the other since the light in
that direction travels slower. On recombination, some of the colors which make up
white light are enhanced by constructive interference and some are suppressed by destructive interference. The result is a color
dependent on the difference between the indices and the thickness of the crystal. The
proper colors, thicknesses, and retardations
are shown on a Michel-Levy chart. The three
items,
retardation,
thickness
and
birefringence are related by the following relationship:
R=t(nγ—nα)
R=retardation, t=crystal thickness in µm,
and
nα,γ=indices of refraction.
Examination of the equation for asbestos
minerals reveals that the visible colors for
almost all common asbestos minerals and
fiber sizes are shades of gray and black. The
eye is relatively poor at discriminating different shades of gray. It is very good at discriminating different colors. In order to
compensate for the low retardation, a compensator is added to the light train between
the polarization elements. The compensator
used for this test is a gypsum plate of known
thickness and birefringence. Such a compensator when oriented at 45° to the polarizer direction, provides a retardation of 530 nm of
4.6. Dispersion Staining
Dispersion microscopy or dispersion staining is the method of choice for the identification of asbestos in bulk materials. Becke
line analysis is used by some laboratories
and yields the same results as does dispersion staining for asbestos and can be used in
lieu of dispersion staining. Dispersion staining is performed on the same platform as the
phase-polar analysis with the analyzer and
compensator removed. One polarizing element remains to define the direction of the
70
light so that the different indices of refraction of the fibers may be separately determined. Dispersion microscopy is a dark-field
technique when used for asbestos. Particles
are imaged with scattered light. Light which
is unscattered is blocked from reaching the
eye either by the back field image mask in a
McCrone objective or a back field image
mask in the phase condenser. The most convenient method is to use the rotating phase
condenser to move an oversized phase ring
into place. The ideal size for this ring is for
the central disk to be just larger than the
objective entry aperture as viewed in the
back focal plane. The larger the disk, the
less scattered light reaches the eye. This will
have the effect of diminishing the intensity
of dispersion color and will shift the actual
color seen. The colors seen vary even on microscopes from the same manufacturer. This
is due to the different bands of wavelength
exclusion by different mask sizes. The mask
may either reside in the condenser or in the
objective back focal plane. It is imperative
that the analyst determine by experimentation with asbestos standards what the appropriate colors should be for each asbestos
type. The colors depend also on the temperature of the preparation and the exact chemistry of the asbestos. Therefore, some slight
differences from the standards should be allowed. This is not a serious problem for commercial asbestos uses. This technique is used
for identification of the indices of refraction
for fibers by recognition of color. There is no
direct numerical readout of the index of refraction. Correlation of color to actual index
of refraction is possible by referral to published conversion tables. This is not necessary for the analysis of asbestos. Recognition of appropriate colors along with the
proper morphology are deemed sufficient to
identify the commercial asbestos minerals.
Other techniques including SEM, TEM, and
XRD may be required to provide additional
information in order to identify other types
of asbestos.
Make a preparation in the suspected
matching high dispersion oil, e.g., n=1.550 for
chrysotile. Perform the preliminary tests to
determine
whether
the
fibers
are
birefringent or not. Take note of the morphological character. Wavy fibers are indicative of chrysotile while long, straight, thin,
frayed fibers are indicative of amphibole asbestos. This can aid in the selection of the
appropriate matching oil. The microscope is
set up and the polarization direction is noted
as in Section 4.4. Align a fiber with the polarization direction. Note the color. This is
the color parallel to the polarizer. Then rotate the fiber rotating the stage 90° so that
the polarization direction is across the fiber.
This is the perpendicular position. Again
note the color. Both colors must be consistent with standard asbestos minerals in
the correct direction for a positive identi-
§ 1910.1001
fication of asbestos. If only one of the colors
is correct while the other is not, the identification is not positive. If the colors in both
directions are bluish-white, the analyst has
chosen a matching index oil which is higher
than the correct matching oil, e.g. the analyst has used n=1.620 where chrysotile is
present. The next lower oil (Section 3.5.)
should be used to prepare another specimen.
If the color in both directions is yellowwhite to straw-yellow-white, this indicates
that the index of the oil is lower than the
index of the fiber, e.g. the preparation is in
n=1.550 while anthophyllite is present. Select
the next higher oil (Section 3.5.) and prepare
another slide. Continue in this fashion until
a positive identification of all asbestos species present has been made or all possible asbestos species have been ruled out by negative results in this test. Certain plant fibers
can have similar dispersion colors as asbestos. Take care to note and evaluate the morphology of the fibers or remove the plant fibers in pre- preparation. Coating material on
the fibers such as carbonate or vinyl may destroy the dispersion color. Usually, there
will be some outcropping of fiber which will
show the colors sufficient for identification.
When this is not the case, treat the sample
as described in Section 3.3. and then perform
dispersion staining. Some samples will yield
to Becke line analysis if they are coated or
electron microscopy can be used for identification.
5. References
5.1. Crane, D.T., Asbestos in Air, OSHA
method ID160, Revised November 1992.
5.2. Ford, W.E., Dana’s Textbook of Mineralogy; Fourth Ed.; John Wiley and Son,
New York, 1950, p. vii.
5.3. Selikoff,.I.J., Lee, D.H.K., Asbestos and
Disease, Academic Press, New York, 1978, pp.
3,20.
5.4. Women Inspectors of Factories. Annual
Report for 1898, H.M. Statistical Office, London, p. 170 (1898).
5.5. Selikoff, I.J., Lee, D.H.K., Asbestos and
Disease, Academic Press, New York, 1978, pp.
26,30.
5.6. Campbell, W.J., et al, Selected Silicate
Minerals and Their Asbestiform Varieties,
United States Department of the Interior,
Bureau of Mines, Information Circular 8751,
1977.
5.7. Asbestos, Code of Federal Regulations,
29 CFR 1910.1001 and 29 CFR 1926.58.
5.8. National Emission Standards for Hazardous Air Pollutants; Asbestos NESHAP Revision, FEDERAL REGISTER, Vol. 55, No. 224, 20
November 1990, p. 48410.
5.9. Ross, M. The Asbestos Minerals: Definitions, Description, Modes of Formation, Physical and Chemical Properties and Health Risk to
the Mining Community, Nation Bureau of
Standards Special Publication, Washington,
DC, 1977.
71
§ 1910.1002
5.10. Lilis, R., Fibrous Zeolites and Endemic Mesothelioma in Cappadocia, Turkey,
J. Occ Medicine, 1981, 23,(8),548–550.
5.11. Occupational Exposure to Asbestos—
1972, U.S. Department of Health, Education
and Welfare, Public Health Service, Center
for Disease Control, National Institute for
Occupational Safety and Health, HSM–72–
10267.
5.12. Campbell, W.J., et al, Relationship of
Mineral Habit to Size Characteristics for
Tremolite Fragments and Fibers, United States
Department of the Interior, Bureau of Mines,
Information Circular 8367, 1979.
5.13. Mefford, D., DCM Laboratory, Denver,
private communication, July 1987.
5.14. Deer, W.A., Howie, R.A., Zussman, J.,
Rock Forming Minerals, Longman, Thetford,
UK, 1974.
5.15. Kerr, P.F., Optical Mineralogy; Third
Ed. McGraw-Hill, New York, 1959.
5.16. Veblen, D.R. (Ed.), Amphiboles and
Other Hydrous Pyriboles—Mineralogy, Reviews
in Mineralogy, Vol 9A, Michigan, 1982, pp 1–
102.
5.17. Dixon, W.C., Applications of Optical Microscopy in the Analysis of Asbestos and
Quartz, ACS Symposium Series, No. 120, Analytical Techniques in Occupational Health
Chemistry, 1979.
5.18. Polarized Light Microscopy, McCrone
Research Institute, Chicago, 1976.
5.19. Asbestos Identification, McCrone Research Institute, G & G printers, Chicago,
1987.
5.20. McCrone, W.C., Calculation of Refractive Indices from Dispersion Staining Data,
The Microscope, No 37, Chicago, 1989.
5.21. Levadie, B. (Ed.), Asbestos and Other
Health Related Silicates, ASTM Technical
Publication 834, ASTM, Philadelphia 1982.
5.22. Steel, E. and Wylie, A., Riordan, P.H.
(Ed.), Mineralogical Characteristics of Asbestos, Geology of Asbestos Deposits, pp. 93–101,
SME–AIME, 1981.
5.23. Zussman, J., The Mineralogy of Asbestos, Asbestos: Properties, Applications and Hazards, pp. 45–67 Wiley, 1979.
coal, petroleum (excluding asphalt),
wood, and other organic matter. Asphalt (CAS 8052–42–4, and CAS 64742–93–
4) is not covered under the ‘‘coal tar
pitch volatiles’’ standard.
[48 FR 2768, Jan. 21, 1983]
§ 1910.1003 13
Carcinogens
(4Nitrobiphenyl, etc.).
(a) Scope and application. (1) This section applies to any area in which the 13
carcinogens addressed by this section
are manufactured, processed, repackaged, released, handled, or stored, but
shall not apply to transshipment in
sealed containers, except for the labeling requirements under paragraphs
(e)(2), (3) and (4) of this section. The 13
carcinogens are the following:
4-Nitrobiphenyl, Chemical Abstracts Service
Register Number (CAS No.) 92933;
alpha-Naphthylamine, CAS No. 134327;
methyl chloromethyl ether, CAS No. 107302;
3,′-Dichlorobenzidine (and its salts) CAS No.
91941;
bis-Chloromethyl ether, CAS No. 542881;
beta-Naphthylamine, CAS No. 91598;
Benzidine, CAS No. 92875;
4-Aminodiphenyl, CAS No. 92671;
Ethyleneimine, CAS No. 151564;
beta-Propiolactone, CAS No. 57578;
2-Acetylaminofluorene, CAS No. 53963;
4-Dimethylaminoazo-benezene,
CAS
No.
60117; and
N-Nitrosodimethylamine, CAS No. 62759.
(2) This section shall not apply to the
following:
(i) Solid or liquid mixtures containing less than 0.1 percent by weight
or volume of 4–Nitrobiphenyl; methyl
chloromethyl ether; bis-chloromethyl
ether; beta-Naphthylamine; benzidine
or 4–Aminodiphenyl; and
(ii) Solid or liquid mixtures containing less than 1.0 percent by weight
or volume of alpha-Naphthylamine; 3,′Dichlorobenzidine
(and
its
salts);
Ethyleneimine; beta-Propiolactone; 2Acetylaminofluorene;
4Dimethylaminoazobenzene,
or
NNitrosodimethylamine.
(b) Definitions. For the purposes of
this section:
Absolute filter is one capable of retaining 99.97 percent of a mono disperse
aerosol of 0.3 µ m particles.
Authorized employee means an employee whose duties require him to be
in the regulated area and who has been
specifically assigned by the employer.
[51 FR 22733, June 20, 1986, as amended at 51
FR 37004, Oct. 17, 1986; 52 FR 17754, 17755, May
12, 1987; 53 FR 35625, September 14, 1988; 54 FR
24334, June 7, 1989; 54 FR 29546, July 13, 1989;
54 FR 52027, Dec. 20, 1989, 55 FR 3731, Feb. 5,
1990; 55 FR 34710, Aug. 24, 1990; 57 FR 24330,
June 8, 1992; 59 FR 41057, Aug. 10, 1994; 60 FR
9625, Feb. 21, 1995; 60 FR 33344, June 28, 1995;
60 FR 33984–33987, June 29, 1995; 61 FR 5508,
Feb. 13, 1996; 61 FR 43457, Aug. 23, 1996; 63 FR
1285, Jan. 8, 1998]
§ 1910.1002 Coal tar pitch volatiles; interpretation of term.
As used in § 1910.1000 (Table Z-1), coal
tar pitch volatiles include the fused
polycyclic hydrocarbons which volatilize from the distillation residues of
72
Clean change room means a room
where employees put on clean clothing
and/or protective equipment in an environment free of the 13 carcinogens addressed by this section. The clean
change room shall be contiguous to and
have an entry from a shower room,
when the shower room facilities are
otherwise required in this section.
Closed system means an operation involving a carcinogen addressed by this
section where containment prevents
the release of the material into regulated areas, non-regulated areas, or the
external environment.
Decontamination means the inactivation of a carcinogen addressed by this
section or its safe disposal.
Director means the Director, National
Institute for Occupational Safety and
Health, or any person directed by him
or the Secretary of Health and Human
Services to act for the Director.
Disposal means the safe removal of
the carcinogens addressed by this section from the work environment.
Emergency means an unforeseen circumstance or set of circumstances resulting in the release of a carcinogen
addressed by this section that may result in exposure to or contact with the
material.
External environment means any environment external to regulated and nonregulated areas.
Isolated system means a fully enclosed
structure other than the vessel of containment of a carcinogen addressed by
this section that is impervious to the
passage of the material and would prevent the entry of the carcinogen addressed by this section into regulated
areas, nonregulated areas, or the external environment, should leakage or
spillage from the vessel of containment
occur.
Laboratory-type hood is a device enclosed on the three sides and the top
and bottom, designed and maintained
so as to draw air inward at an average
linear face velocity of 150 feet per
minute with a minimum of 125 feet per
minute; designed, constructed, and
maintained in such a way that an operation involving a carcinogen addressed
by this section within the hood does
not require the insertion of any portion
of any employee’s body other than his
hands and arms.
§ 1910.1003
Nonregulated area means any area
under the control of the employer
where entry and exit is neither restricted nor controlled.
Open-vessel system means an operation involving a carcinogen addressed
by this section in an open vessel that is
not in an isolated system, a laboratory-type hood, nor in any other system affording equivalent protection
against the entry of the material into
regulated areas, non-regulated areas,
or the external environment.
Protective clothing means clothing designed to protect an employee against
contact with or exposure to a carcinogen addressed by this section.
Regulated area means an area where
entry and exit is restricted and controlled.
(c) Requirements for areas containing a
carcinogen addressed by this section. A
regulated area shall be established by
an employer where a carcinogen addressed by this section is manufactured, processed, used, repackaged, released, handled or stored. All such
areas shall be controlled in accordance
with the requirements for the following
category or categories describing the
operation involved:
(1) Isolated systems. Employees working with a carcinogen addressed by this
section within an isolated system such
as a ‘‘glove box’’ shall wash their hands
and arms upon completion of the assigned task and before engaging in
other activities not associated with the
isolated system.
(2) Closed system operation. (i) Within
regulated areas where the carcinogens
addressed by this section are stored in
sealed containers, or contained in a
closed system, including piping systems, with any sample ports or openings closed while the carcinogens addressed by this section are contained
within, access shall be restricted to authorized employees only.
(ii)
Employees
exposed
to
4–
Nitrobiphenyl; alpha-Naphthylamine;
3,′-Dichlorobenzidine (and its salts);
beta-Naphthylamine;
benzidine;
4–
Aminodiphenyl;
2–
Acetylaminofluorene;
4–
Dimethylaminoazo-benzene; and NNitrosodimethylamine shall be required to wash hands, forearms, face,
73
§ 1910.1003
and neck upon each exit from the regulated areas, close to the point of exit,
and before engaging in other activities.
(3) Open-vessel system operations.
Open-vessel system operations as defined in paragraph (b)(13) of this section are prohibited.
(4) Transfer from a closed system,
charging or discharging point operations,
or otherwise opening a closed system. In
operations involving ‘‘laboratory-type
hoods,’’ or in locations where the carcinogens addressed by this section are
contained in an otherwise ‘‘closed system,’’ but is transferred, charged, or
discharged into other normally closed
containers, the provisions of this paragraph shall apply.
(i) Access shall be restricted to authorized employees only.
(ii) Each operation shall be provided
with continuous local exhaust ventilation so that air movement is always
from ordinary work areas to the operation. Exhaust air shall not be discharged to regulated areas, nonregulated areas or the external environment unless decontaminated. Clean
makeup air shall be introduced in sufficient volume to maintain the correct
operation of the local exhaust system.
(iii) Employees shall be provided
with, and required to wear, clean, full
body protective clothing (smocks, coveralls, or long-sleeved shirt and pants),
shoe covers and gloves prior to entering the regulated area.
(iv) Employees engaged in handling
operations involving the carcinogens
addressed by this section must be provided with, and required to wear and
use a half-face filter-type respirator
with filters for dusts, mists, and fumes,
or air-purifying canisters or cartridges.
A respirator affording higher levels of
protection than this respirator may be
substituted.
(v) Prior to each exit from a regulated area, employees shall be required
to remove and leave protective clothing and equipment at the point of exit
and at the last exit of the day, to place
used clothing and equipment in impervious containers at the point of exit for
purposes of decontamination or disposal. The contents of such impervious
containers shall be identified, as required under paragraphs (e) (2), (3), and
(4) of this section.
(vi) Drinking fountains are prohibited in the regulated area.
(vii) Employees shall be required to
wash hands, forearms, face, and neck
on each exit from the regulated area,
close to the point of exit, and before
engaging in other activities and employees exposed to 4–Nitrobiphenyl;
alpha-Naphthylamine;
3,′Dichlorobenzidine (and its salts); betaNaphthylamine;
Benzidine;
4–
Aminodiphenyl;
2–
4–
Dimethylaminoazo-benzene; and NNitrosodimethylamine shall be required to shower after the last exit of
the day.
(5) Maintenance and decontamination
activities. In cleanup of leaks of spills,
maintenance, or repair operations on
contaminated systems or equipment,
or any operations involving work in an
area where direct contact with a carcinogen addressed by this section could
result, each authorized employee entering that area shall:
(i) Be provided with and required to
wear clean, impervious garments, including gloves, boots, and continuousair supplied hood in accordance with
§ 1910.134;
(ii) Be decontaminated before removing the protective garments and hood;
(iii) Be required to shower upon removing the protective garments and
hood.
(d) General regulated area requirements—(1) Respirator program. The employer must implement a respiratory
29 CFR 1910.134 (b), (c), (d) (except
(d)(1)(iii) and (iv), and (d)(3)), and (e)
through (m).
(2) Emergencies. In an emergency, immediate measures including, but not
limited to, the requirements of paragraphs (d)(2) (i) through (v) of this section shall be implemented.
(i) The potentially affected area shall
be evacuated as soon as the emergency
has been determined.
(ii) Hazardous conditions created by
the emergency shall be eliminated and
the potentially affected area shall be
decontaminated prior to the resumption of normal operations.
(iii) Special medical surveillance by a
physician shall be instituted within 24
74
hours for employees present in the potentially affected area at the time of
the emergency. A report of the medical
surveillance and any treatment shall
be included in the incident report, in
accordance with paragraph (f)(2) of this
section.
(iv) Where an employee has a known
contact with a carcinogen addressed by
this section, such employee shall be required to shower as soon as possible,
unless contraindicated by physical injuries.
(v) An incident report on the emergency shall be reported as provided in
paragraph (f)(2) of this section.
(vi) Emergency deluge showers and
eyewash fountains supplied with running potable water shall be located
near, within sight of, and on the same
level with locations where a direct exposure to Ethyleneimine or betaPropiolactone only would be most likely as a result of equipment failure or
improper work practice.
(3) Hygiene facilities and practices. (i)
Storage or consumption of food, storage or use of containers of beverages,
storage or application of cosmetics,
smoking, storage of smoking materials, tobacco products or other products for chewing, or the chewing of
such products are prohibited in regulated areas.
(ii) Where employees are required by
this section to wash, washing facilities
shall be provided in accordance with
§ 1910.141(d) (1) and (2) (ii) through (vii).
(iii) Where employees are required by
this section to shower, shower facilities shall be provided in accordance
with § 1910.141(d)(3).
(iv) Where employees wear protective
clothing and equipment, clean change
rooms shall be provided for the number
of such employees required to change
clothes, in accordance with § 1910.141(e).
(v) Where toilets are in regulated
areas, such toilets shall be in a separate room.
(4) Contamination control. (i) Except
for outdoor systems, regulated areas
shall be maintained under pressure
negative with respect to nonregulated
areas. Local exhaust ventilation may
be used to satisfy this requirement.
Clean makeup air in equal volume
shall replace air removed.
§ 1910.1003
(ii) Any equipment, material, or
other item taken into or removed from
a regulated area shall be done so in a
manner that does not cause contamination in nonregulated areas or the external environment.
(iii)
Decontamination
procedures
shall be established and implemented
to remove carcinogens addressed by
this section from the surfaces of materials, equipment, and the decontamination facility.
(iv) Dry sweeping and dry mopping
are prohibited for 4–Nitrobiphenyl;
alpha-Naphthylamine;
3,′Dichlorobenzidine (and its salts); betaNaphthylamine;
Benzidine;
4–
Aminodiphenyl;
2–
4–
Dimethylaminoazo-benzene
and
NNitrosodimethylamine.
(e) Signs, information and training—(1)
Signs—(i) Entrances to regulated areas
shall be posted with signs bearing the
legend:
CANCER-SUSPECT AGENT
(ii) Entrances to regulated areas containing operations covered in paragraph (c)(5) of this section shall be
posted with signs bearing the legend:
CANCER-SUSPECT AGENT EXPOSED
IN THIS AREA
IMPERVIOUS
SUIT
INCLUDING
GLOVES, BOOTS, AND AIR-SUPPLIED HOOD REQUIRED AT ALL
TIMES
(iii) Appropriate signs and instructions shall be posted at the entrance
to, and exit from, regulated areas, informing employees of the procedures
that must be followed in entering and
leaving a regulated area.
(2) Container contents identification. (i)
Containers of a carcinogen addressed
by this section and containers required
under paragraphs (c)(4)(v) and (c)(6)
(vii)(B) and (viii)(B) of this section that
are accessible only to and handled only
by authorized employees, or by other
employees trained in accordance with
paragraph (e)(5) of this section, may
have contents identification limited to
75
§ 1910.1003
a generic or proprietary name or other
proprietary identification of the carcinogen and percent.
(ii) Containers of a carcinogen addressed by this section and containers
required under paragraphs (c)(4)(v) and
(c)(6) (vii)(B) and (viii)(B) of this section that are accessible to or handled
by employees other than authorized
employees or employees trained in accordance with paragraph (e)(5) of this
section shall have contents identification that includes the full chemical
name and Chemical Abstracts Service
Registry number as listed in paragraph
(a)(1) of this section.
(iii) Containers shall have the warning
words
‘‘CANCER-SUSPECT
AGENT’’ displayed immediately under
or adjacent to the contents identification.
(iv) Containers whose contents are
carcinogens addressed by this section
with corrosive or irritating properties
shall have label statements warning of
such hazards noting, if appropriate,
particularly sensitive or affected portions of the body.
(3) Lettering. Lettering on signs and
instructions required by paragraph
(e)(1) shall be a minimum letter height
of 2 inches (5 cm). Labels on containers
required under this section shall not be
less than one-half the size of the largest lettering on the package, and not
less than 8-point type in any instance.
Provided, That no such required lettering need be more than 1 inch (2.5
cm) in height.
(4) Prohibited statements. No statement shall appear on or near any required sign, label, or instruction that
contradicts or detracts from the effect
of any required warning, information,
or instruction.
(5) Training and indoctrination. (i)
Each employee prior to being authorized to enter a regulated area, shall receive a training and indoctrination
program including, but not necessarily
limited to:
(A) The nature of the carcinogenic
hazards of a carcinogen addressed by
this section, including local and systemic toxicity;
(B) The specific nature of the operation involving a carcinogen addressed
by this section that could result in exposure;
(C) The purpose for and application of
the medical surveillance program, including, as appropriate, methods of
self-examination;
(D) The purpose for and application
of decontamination practices and purposes;
(E) The purpose for and significance
of emergency practices and procedures;
(F) The employee’s specific role in
emergency procedures;
(G) Specific information to aid the
employee in recognition and evaluation of conditions and situations which
may result in the release of a carcinogen addressed by this section;
(H) The purpose for and application
of specific first aid procedures and
practices;
(I) A review of this section at the employee’s first training and indoctrination program and annually thereafter.
(ii) Specific emergency procedures
shall be prescribed, and posted, and employees shall be familiarized with their
terms, and rehearsed in their application.
(iii) All materials relating to the program shall be provided upon request to
authorized representatives of the Assistant Secretary and the Director.
(f) Reports—(1) Operations. The information required in paragraphs (f)(1) (i)
through (iv) of this section shall be reported in writing to the nearest OSHA
Area Director. Any changes in such information shall be similarly reported
in writing within 15 calendar days of
such change:
(i) A brief description and in-plant location of the area(s) regulated and the
address of each regulated area;
(ii) The name(s) and other identifying information as to the presence of
a carcinogen addressed by this section
in each regulated area;
(iii) The number of employees in each
regulated area, during normal operations including maintenance activities; and
(iv) The manner in which carcinogens
addressed by this section are present in
each regulated area; for example,
whether it is manufactured, processed,
used, repackaged, released, stored, or
otherwise handled.
(2) Incidents. Incidents that result in
the release of a carcinogen addressed
76
§ 1910.1009
(2) Records. (i) Employers of employees examined pursuant to this paragraph shall cause to be maintained
complete and accurate records of all
such medical examinations. Records
shall be maintained for the duration of
the employee’s employment. Upon termination of the employee’s employment, including retirement or death, or
in the event that the employer ceases
business without a successor, records,
or notarized true copies thereof, shall
be forwarded by registered mail to the
Director.
(ii) Records required by this paragraph shall be provided upon request to
employees, designated representatives,
and the Assistant Secretary in accordance with 29 CFR 1910.20 (a) through (e)
and (g) through (i). These records shall
also be provided upon request to the
Director.
(iii) Any physician who conducts a
medical examination required by this
paragraph shall furnish to the employer a statement of the employee’s
suitability for employment in the specific exposure.
by this section into any area where employees may be potentially exposed
shall be reported in accordance with
this paragraph.
(i) A report of the occurrence of the
incident and the facts obtainable at
that time including a report on any
medical treatment of affected employees shall be made within 24 hours to
the nearest OSHA Area Director.
(ii) A written report shall be filed
with the nearest OSHA Area Director
within 15 calendar days thereafter and
shall include:
(A) A specification of the amount of
material released, the amount of time
involved, and an explanation of the
procedure used in determining this figure;
(B) A description of the area involved, and the extent of known and
possible employee exposure and area
contamination;
(C) A report of any medical treatment of affected employees, and any
medical surveillance program implemented; and
(D) An analysis of the circumstances
of the incident and measures taken or
to be taken, with specific completion
dates, to avoid further similar releases.
(g) Medical surveillance. At no cost to
the employee, a program of medical
surveillance shall be established and
implemented for employees considered
for assignment to enter regulated
areas, and for authorized employees.
(1) Examinations. (i) Before an employee is assigned to enter a regulated
area, a preassignment physical examination by a physician shall be provided. The examination shall include
the personal history of the employee,
family and occupational background,
including genetic and environmental
factors.
(ii) Authorized employees shall be
provided periodic physical examinations, not less often than annually, following the preassignment examination.
(iii) In all physical examinations, the
examining physician shall consider
whether there exist conditions of increased
risk,
including
reduced
immunological competence, those undergoing treatment with steroids or
cytotoxic agents, pregnancy, and cigarette smoking.
[61 FR 9242, Mar. 7, 1996, as amended at 63 FR
1286, Jan. 8, 1998; 63 FR 20099, Apr. 23, 1998]
§ 1910.1004
alpha-Naphthylamine.
See § 1910.1003, 13 carcinogens.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1005
[Reserved]
§ 1910.1006
Methyl chloromethyl ether.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1007 3,′-Dichlorobenzidine
its salts).
(and
[61 FR 9245, Mar. 7, 1996]
§ 1910.1008
bis-Chloromethyl ether.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1009
beta-Naphthylamine.
[61 FR 9245, Mar. 7, 1996]
77
§ 1910.1010
(3) Authorized person means any person specifically authorized by the employer whose duties require him to
enter a regulated area or any person
entering such an area as a designated
representative of employees for the
purpose of exercising an opportunity to
observe monitoring and measuring procedures.
(4) Director means the Director, National Institute for Occupational Safety and Health, U.S. Department of
Health and Human Services, or his designee.
(5) Emergency means any occurrence
such as, but not limited to, equipment
failure, or operation of a relief device
which is likely to, or does, result in
massive release of vinyl chloride.
(6) Fabricated product means a product made wholly or partly from polyvinyl chloride, and which does not require further processing at temperatures, and for times, sufficient to cause
mass melting of the polyvinyl chloride
resulting in the release of vinyl chloride.
(7) Hazardous operation means any operation, procedure, or activity where a
release of either vinyl chloride liquid
or gas might be expected as a consequence of the operation or because of
an accident in the operation, which
would result in an employee exposure
in excess of the permissible exposure
limit.
(8) OSHA Area Director means the Director for the Occupational Safety and
Health Administration Area Office having jurisdiction over the geographic
area in which the employer’s establishment is located.
(9) Polyvinyl chloride means polyvinyl
chloride homopolymer or copolymer
before such is converted to a fabricated
product.
(10) Vinyl chloride means vinyl chloride monomer.
(c) Permissible exposure limit. (1) No
employee may be exposed to vinyl
chloride at concentrations greater than
1 ppm averaged over any 8-hour period,
and
(2) No employee may be exposed to
vinyl chloride at concentrations greater than 5 ppm averaged over any period
not exceeding 15 minutes.
§ 1910.1010 Benzidine.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1011 4-Aminodiphenyl.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1012 Ethyleneimine.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1013 beta-Propiolactone.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1014 2-Acetylaminofluorene.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1015 4-Dimethylaminoazobenzene.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1016 N-Nitrosodimethylamine.
[61 FR 9245, Mar. 7, 1996]
§ 1910.1017 Vinyl chloride.
(a) Scope and application. (1) This section includes requirements for the control of employee exposure to vinyl
chloride (chloroethene), Chemical Abstracts Service Registry No. 75014.
(2) This section applies to the manufacture, reaction, packaging, repackaging, storage, handling or use of vinyl
chloride or polyvinyl chloride, but does
not apply to the handling or use of fabricated products made of polyvinyl
chloride.
(3) This section applies to the transportation of vinyl chloride or polyvinyl
chloride except to the extent that the
Department of Transportation may
regulate the hazards covered by this
section.
(b) Definitions. (1) Action level means a
concentration of vinyl chloride of 0.5
ppm averaged over an 8-hour work day.
(2) Assistant Secretary means the Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or his designee.
78
§ 1910.1017
(e) Regulated area. (1) A regulated
area shall be established where:
(i) Vinyl chloride or polyvinyl chloride is manufactured, reacted, repackaged, stored, handled or used; and
(ii) Vinyl chloride concentrations are
in excess of the permissible exposure
limit.
(2) Access to regulated areas shall be
limited to authorized persons.
(f) Methods of compliance. Employee
exposures to vinyl chloride shall be
controlled to at or below the permissible exposure limit provided in paragraph (c) of this section by engineering, work practice, and personal protective controls as follows:
(1) Feasible engineering and work
practice controls shall immediately be
used to reduce exposures to at or below
the permissible exposure limit.
(2) Wherever feasible engineering and
work practice controls which can be instituted immediately are not sufficient
to reduce exposures to at or below the
permissible exposure limit, they shall
nonetheless be used to reduce exposures to the lowest practicable level,
and shall be supplemented by respiratory protection in accordance with
paragraph (g) of this section. A program shall be established and implemented to reduce exposures to at or
below the permissible exposure limit,
or to the greatest extent feasible, solely by means of engineering and work
practice controls, as soon as feasible.
(3) Written plans for such a program
shall be developed and furnished upon
request for examination and copying to
authorized representatives of the Assistant Secretary and the Director.
Such plans shall be updated at least
every six months.
with the requirements of this paragraph.
(2) Respirator program. The employer
must implement a respiratory protection program in accordance with 29
CFR 1910.134 (b) through (d) (except
(d)(1)(iii), and (d)(3)(iii)(B)(1) and (2)),
and (f) through (m).
(3) Respirator selection. (i) Respirators
must be selected from the following
table:
(3) No employee may be exposed to
vinyl chloride by direct contact with
liquid vinyl chloride.
(d) Monitoring. (1) A program of initial monitoring and measurement shall
be undertaken in each establishment to
determine if there is any employee exposed, without regard to the use of respirators, in excess of the action level.
(2) Where a determination conducted
under paragraph (d)(1) of this section
shows any employee exposures, without regard to the use of respirators, in
excess of the action level, a program
for determining exposures for each
such employee shall be established.
Such a program:
(i) Shall be repeated at least monthly
where any employee is exposed, without regard to the use of respirators, in
excess of the permissible exposure
limit.
(ii) Shall be repeated not less than
quarterly where any employee is exposed, without regard to the use of respirators, in excess of the action level.
(iii) May be discontinued for any employee only when at least two consecutive monitoring determinations, made
not less than 5 working days apart,
show exposures for that employee at or
below the action level.
(3) Whenever there has been a production, process or control change which
may result in an increase in the release
of vinyl chloride, or the employer has
any other reason to suspect that any
employee may be exposed in excess of
the action level, a determination of
employee exposure under paragraph
(d)(1) of this section shall be performed.
(4) The method of monitoring and
measurement shall have an accuracy
(with a confidence level of 95 percent)
of not less than plus or minus 50 percent from 0.25 through 0.5 ppm, plus or
minus 35 percent from over 0.5 ppm
through 1.0 ppm, and plus or minus 25
percent over 1.0 ppm. (Methods meeting
these accuracy requirements are available in the ‘‘NIOSH Manual of Analytical Methods’’).
(5) Employees or their designated
representatives shall be afforded reasonable opportunity to observe the
monitoring and measuring required by
this paragraph.
79
§ 1910.1017
Atmospheric concentration of vinyl chloride
Required apparatus
(i) Unknown, or above 3,600 p/m ...............
Open-circuit, self-contained breathing apparatus, pressure demand type, with full
facepiece.
(A) Combination type C supplied air respirator, pressure demand type, with full or
half facepiece, and auxiliary self-contained air supply; or
(B) Combination type, supplied air respirator continuous flow type, with full or half
facepiece, and auxiliary self-contained air supply. Type C, supplied air respirator,
continuous flow type, with full or half facepiece, helmet or hood.
(A) Combination type C supplied air respirator demand type, with full facepiece,
and auxiliary self-contained air supply; or
(B) Open-circuit self-contained breathing apparatus with full facepiece, in demand
mode; or
Type (C) supplied air respirator, demand type, with full facepiece.
(A) A powered air-purifying respirator with hood, helmet, full or half facepiece, and
a canister which provides a service life of at least 4 hours for concentrations of
vinyl chloride up to 25 p/m, or
(B) Gas mask, front- or back-mounted canister which provides a service life of at
least 4 hours for concentrations of vinyl chloride up to 25 p/m.
(A) Combination type C supplied-air respirator, demand type, with half facepiece,
and auxiliary self-contained air supply; or
(B) Type C supplied-air respirator, demand type, with half facepiece; or
(C) Any chemical cartridge respirator with an organic vapor cartridge which provides a service life of at least 1 hour for concentrations of vinyl chloride up to 10
p/m.
(ii) Not over 3,600 p/m ................................
(iii) Not over 1,000 p/m ...............................
(iv) Not over 100 p/m ..................................
(v) Not over 25 p/m .....................................
(vi) Not over 10 p/m ....................................
(i) Emergency situations. A written
operational plan for emergency situations shall be developed for each facility storing, handling, or otherwise
using vinyl chloride as a liquid or compressed gas. Appropriate portions of
the plan shall be implemented in the
event of an emergency. The plan shall
specifically provide that:
(1) Employees engaged in hazardous
operations or correcting situations of
existing hazardous releases shall be
equipped as required in paragraph (h)
of this section;
(2) Other employees not so equipped
shall evacuate the area and not return
until conditions are controlled by the
methods required in paragraph (f) of
this section and the emergency is
abated.
(j) Training. Each employee engaged
in vinyl chloride or polyvinyl chloride
operations shall be provided training in
a program relating to the hazards of
vinyl chloride and precautions for its
safe use.
(1) The program shall include:
(i) The nature of the health hazard
from chronic exposure to vinyl chloride
including specifically the carcinogenic
hazard;
(ii) The specific nature of operations
which could result in exposure to vinyl
chloride in excess of the permissible
limit and necessary protective steps;
(ii) When air-purifying respirators
are used:
(A) Air-purifying canisters or cartridges must be replaced prior to the
expiration of their service life or the
end of the shift in which they are first
used, whichever occurs first.
(B) A continuous-monitoring and
alarm system must be provided when
concentrations of vinyl chloride could
reasonably exceed the allowable concentrations for the devices in use. Such
a system must be used to alert employees when vinyl chloride concentrations
exceed the allowable concentrations
for the devices in use.
(iii) Respirators specified for higher
concentrations may be used for lower
concentrations.
(h) Hazardous operations. (1) Employees engaged in hazardous operations,
including entry of vessels to clean polyvinyl chloride residue from vessel
walls, shall be provided and required to
wear and use;
(i) Respiratory protection in accordance with paragraphs (c) and (g) of this
section; and
(ii) Protective garments to prevent
skin contact with liquid vinyl chloride
or with polyvinyl chloride residue from
vessel walls. The protective garments
shall be selected for the operation and
its possible exposure conditions.
(2) Protective garments shall be provided clean and dry for each use.
80
(iii) The purpose for, proper use, and
limitations of respiratory protective
devices;
(iv) The fire hazard and acute toxicity of vinyl chloride, and the necessary protective steps;
(v) The purpose for and a description
of the monitoring program;
(vi) The purpose for, and a description of, the medical surveillance program;
(vii) Emergency procedures;
(viii) Specific information to aid the
employee in recognition of conditions
which may result in the release of
vinyl chloride; and
(ix) A review of this standard at the
employee’s first training and indoctrination program, and annually thereafter.
(2) All materials relating to the program shall be provided upon request to
the Assistant Secretary and the Director.
(k) Medical surveillance. A program of
medical surveillance shall be instituted
for each employee exposed, without regard to the use of respirators, to vinyl
chloride in excess of the action level.
The program shall provide each such
employee with an opportunity for examinations and tests in accordance
with this paragraph. All medical examinations and procedures shall be
performed by or under the supervision
of a licensed physician, and shall be
provided without cost to the employee.
(1) At the time of initial assignment,
or upon institution of medical surveillance;
(i) A general physical examination
shall be performed, with specific attention to detecting enlargement of liver,
spleen or kidneys, or dysfunction in
these organs, and for abnormalities in
skin, connective tissues and the pulmonary system (See Appendix A).
(ii) A medical history shall be taken,
including the following topics:
(A) Alcohol intake;
(B) Past history of hepatitis;
(C) Work history and past exposure
to potential hepatotoxic agents, including drugs and chemicals;
(D) Past history of blood transfusions; and
(E) Past history of hospitalizations.
(iii) A serum specimen shall be obtained and determinations made of:
§ 1910.1017
(A) Total bilirubin;
(B) Alkaline phosphatase;
(C) Serum glutamic oxalacetic transaminase (SGOT);
(D) Serum glutamic pyruvic transaminase (SGPT); and
(E)
Gamma
glustamyl
transpeptidase.
(2) Examinations provided in accordance with this paragraph shall be performed at least:
(i) Every 6 months for each employee
who has been employed in vinyl chloride or polyvinyl chloride manufacturing for 10 years or longer; and
(ii) Annually for all other employees.
(3) Each employee exposed to an
emergency shall be afforded appropriate medical surveillance.
(4) A statement of each employee’s
suitability for continued exposure to
vinyl chloride including use of protective equipment and respirators, shall
be obtained from the examining physician promptly after any examination.
A copy of the physician’s statement
shall be provided each employee.
(5) If any employee’s health would be
materially impaired by continued exposure, such employee shall be withdrawn from possible contact with vinyl
chloride.
(6) Laboratory analyses for all biological specimens included in medical
examinations shall be performed in
laboratories licensed under 42 CFR
Part 74.
(7) If the examining physician determines that alternative medical examinations to those required by paragraph
(k)(1) of this section will provide at
least equal assurance of detecting medical conditions pertinent to the exposure to vinyl chloride, the employer
may accept such alternative examinations as meeting the requirements of
paragraph (k)(1) of this section, if the
employer obtains a statement from the
examining physician setting forth the
alternative examinations and the rationale for substitution. This statement shall be available upon request
for examination and copying to authorized representatives of the Assistant
Secretary and the Director.
(l) Signs and labels. (1) Entrances to
regulated areas shall be posted with
legible signs bearing the legend:
81
§ 1910.1017
CANCER-SUSPECT AGENT AREA
ployees, designated representatives,
and (g) through (i). These records shall
be provided upon request to the Director. Authorized personnel rosters shall
also be provided upon request to the
Assistant Secretary and the Director.
(i) Monitoring and measuring records
shall:
(A) State the date of such monitoring
and measuring and the concentrations
determined and identify the instruments and methods used;
(B) Include any additional information necessary to determine individual
employee exposures where such exposures are determined by means other
than individual monitoring of employees; and
(C) Be maintained for not less than 30
years.
(ii) [Reserved]
(iii) Medical records shall be maintained for the duration of the employment of each employee plus 20 years, or
30 years, whichever is longer.
(3) In the event that the employer
ceases to do business and there is no
successor to receive and retain his
records for the prescribed period, these
records shall be transmitted by registered mail to the Director, and each
employee individually notified in writing of this transfer. The employer shall
also comply with any additional requirements set forth in 29 CFR
1910.20(h).
(n) Reports. (1) Not later than 1
month after the establishment of a regulated area, the following information
shall be reported to the OSHA Area Director. Any changes to such information shall be reported within 15 days.
(i) The address and location of each
establishment which has one or more
regulated areas; and
(ii) The number of employees in each
regulated area during normal operations, including maintenance.
(2) Emergencies, and the facts obtainable at that time, shall be reported
within 24 hours to the OSHA Area Director. Upon request of the Area Director, the employer shall submit additional information in writing relevant
to the nature and extent of employee
(2) Areas containing hazardous operations or where an emergency currently exists shall be posted with legible signs bearing the legend:
CANCER-SUSPECT AGENT IN THIS AREA
PROTECTIVE EQUIPMENT REQUIRED AUTHORIZED PERSONNEL ONLY
(3) Containers of polyvinyl chloride
resin waste from reactors or other
waste contaminated with vinyl chloride shall be legibly labeled:
CONTAMINATED WITH VINYL CHLORIDE
(4) Containers of polyvinyl chloride
shall be legibly labeled:
POLYVINYL CHLORIDE (OR TRADE NAME)
Contains
VINYL CHLORIDE
VINYL CHLORIDE IS A CANCER-SUSPECT
AGENT
(5) Containers of vinyl chloride shall
be legibly labeled either:
(i)
VINYL CHLORIDE
EXTREMELY FLAMMABLE GAS UNDER
PRESSURE
CANCER SUSPECT AGENT
or (ii) In accordance with 49 CFR Parts
170 through 189, with the additional
legend:
applied near the label or placard.
(6) No statement shall appear on or
near any required sign, label or instruction which contradicts or detracts
from the effect of, any required warning, information or instruction.
(m) Records. (1) All records maintained in accordance with this section
shall include the name and social security number of each employee where
relevant.
(2) Records of required monitoring
and measuring and medical records
shall be provided upon request to em-
82
§ 1910.1018
wood with preservatives or the utilization of arsenically preserved wood.
(b) Definitions. Action level means a
concentration of inorganic arsenic of 5
micrograms per cubic meter of air (5
µg/m3) averaged over any eight (8) hour
period.
specifically authorized by the employer
whose duties require the person to
enter a regulated area, or any person
purpose of exercising the right to observe monitoring and measuring procedures under paragraph (e) of this section.
Health, U.S. Department of Health and
Human Services, or designee.
Inorganic arsenic means copper acetoarsenite and all inorganic compounds
containing arsenic except arsine, measured as arsenic (As).
(c) Permissible exposure limit. The employer shall assure that no employee is
exposed to inorganic arsenic at concentrations
greater
than
10
3
µg/m ), averaged over any 8-hour period.
(d) Notification of use. (1) By October
1, 1978 or within 60 days after the introduction of inorganic arsenic into the
workplace, every employer who is required to establish a regulated area in
his workplaces shall report in writing
to the OSHA area office for each such
workplace:
(i) The address of each such workplace;
(ii) The approximate number of employees who will be working in regulated areas; and
(iii) A brief summary of the operations creating the exposure and the
actions which the employer intends to
take to reduce exposures.
(2) Whenever there has been a significant change in the information required by paragraph (d)(1) of this section the employer shall report the
changes in writing within 60 days to
the OSHA area office.
exposures and measures taken to prevent future emergencies of similar nature.
(3) Within 10 working days following
any monitoring and measuring which
discloses that any employee has been
exposed, without regard to the use of
respirators, in excess of the permissible
exposure limit, each such employee
shall be notified in writing of the results of the exposure measurement and
the steps being taken to reduce the exposure to within the permissible exposure limit.
(o) Effective dates. (1) Until April 1,
1975, the provisions currently set forth
in § 1910.93q of this part shall apply.
(2) Effective April 1, 1975, the provisions set forth in § 1910.93q of this part
shall apply.
APPENDIX A TO § 1910.1017—
SUPPLEMENTARY MEDICAL INFORMATION
When required tests under paragraph (k)(1)
of this section show abnormalities, the tests
should be repeated as soon as practicable,
preferably within 3 to 4 weeks. If tests remain abnormal, consideration should be
given to withdrawal of the employee from
contact with vinyl chloride, while a more
comprehensive examination is made.
Additional tests which may be useful:
A. For kidney dysfunction: urine examination for albumin, red blood cells, and
exfoliative abnormal cells.
B. Pulmonary system: Forced vital capacity, Forced expiratory volume at 1 second,
and chest roentgenogram (posterior-anterior,
14 × 17 inches).
C. Additional serum tests: Lactic acid dehydrogenase, lactic acid dehydrogenase
isoenzyme, protein determination, and protein electrophoresis.
D. For a more comprehensive examination
on repeated abnormal serum tests: Hepatitis
B antigen, and liver scanning.
[39 FR 35896, Oct. 4, 1974; 39 FR 41848, Dec. 3,
1974, as amended at 40 FR 13211, Mar. 25, 1975.
Redesignated at 40 FR 23072, May 28, 1975 and
amended at 43 FR 49751, Oct. 24, 1978; 45 FR
35282, May 23, 1980; 54 FR 24334, June 7, 1989;
58 FR 35310, June 30, 1993; 61 FR 5508, Feb. 13,
1996; 63 FR 1286, Jan. 8, 1998]
§ 1910.1018 Inorganic arsenic.
(a) Scope and application. This section
applies to all occupational exposures to
inorganic arsenic except that this section does not apply to employee exposures in agriculture or resulting from
pesticide application, the treatment of
83
§ 1910.1018
(e) Exposure monitoring—(1) General.
(i) Determinations of airborne exposure
levels shall be made from air samples
that are representative of each employee’s exposure to inorganic arsenic over
an eight (8) hour period.
(ii) For the purposes of this section,
employee exposure is that exposure
which would occur if the employee
were not using a respirator.
(iii) The employer shall collect full
shift (for at least 7 continuous hours)
personal samples including at least one
sample for each shift for each job classification in each work area.
(2) Initial monitoring. Each employer
who has a workplace or work operation
covered by this standard shall monitor
each such workplace and work operation to accurately determine the airborne concentration of inorganic arsenic to which employees may be exposed.
(3) Frequency. (i) If the initial monitoring reveals employee exposure to be
below the action level the measurements need not be repeated except as
otherwise provided in paragraph (e)(4)
of this section.
(ii) If the initial monitoring, required
by this section, or subsequent monitoring reveals employee exposure to be
above the permissible exposure limit,
the employer shall repeat monitoring
at least quarterly.
(iii) If the initial monitoring, required by this section, or subsequent
monitoring reveals employee exposure
to be above the action level and below
the permissible exposure limit the employer shall repeat monitoring at least
every six months.
(iv) The employer shall continue
monitoring at the required frequency
until at least two consecutive measurements, taken at least seven (7) days
apart, are below the action level at
which time the employer may discontinue monitoring for that employee
until such time as any of the events in
paragraph (e)(4) of this section occur.
(4) Additional monitoring. Whenever
there has been a production, process,
control or personal change which may
result in new or additional exposure to
inorganic arsenic, or whenever the employer has any other reason to suspect
a change which may result in new or
additional exposures to inorganic ar-
senic, additional monitoring which
complies with paragraph (e) of this section shall be conducted.
(5) Employee notification. (i) Within
five (5) working days after the receipt
of monitoring results, the employer
shall notify each employee in writing
of the results which represent that employee’s exposures.
(ii) Whenever the results indicate
that the representative employee exposure exceeds the permissible exposure
limit, the employer shall include in the
written notice a statement that the
permissible exposure limit was exceeded and a description of the corrective
action taken to reduce exposure to or
below the permissible exposure limit.
(6) Accuracy of measurement. (i) The
employer shall use a method of monitoring and measurement which has an
accuracy (with a confidence level of 95
percent) of not less than plus or minus
25 percent for concentrations of inorganic arsenic greater than or equal to
10 µg/m3.
(ii) The employer shall use a method
of monitoring and measurement which
has an accuracy (with confidence level
of 95 percent) of not less than plus or
minus 35 percent for concentrations of
inorganic arsenic greater than 5 µg/
m3but less than 10 µg/m3.
(f) Regulated area—(1) Establishment.
The employer shall establish regulated
areas where worker exposures to inorganic arsenic, without regard to the
use of respirators, are in excess of the
permissible limit.
be demarcated and segregated from the
rest of the workplace in any manner
that minimizes the number of persons
who will be exposed to inorganic arsenic.
shall be limited to authorized persons
or to persons otherwise authorized by
the Act or regulations issued pursuant
thereto to enter such areas.
(4) Provision of respirators. All persons
entering a regulated area shall be supplied with a respirator, selected in accordance with paragraph (h)(2) of this
section.
shall assure that in regulated areas,
food or beverages are not consumed,
smoking products, chewing tobacco
84
and gum are not used and cosmetics
are not applied, except that these activities may be conducted in the
lunchrooms, change rooms and showers
required under paragraph (m) of this
section. Drinking water may be consumed in the regulated area.
(g) Methods of compliance—(1) Controls. (i) The employer shall institute at
the earliest possible time but not later
than December 31, 1979, engineering
and work practice controls to reduce
exposures to or below the permissible
exposure limit, except to the extent
that the employer can establish that
such controls are not feasible.
(ii) Where engineering and work
practice controls are not sufficient to
reduce exposures to or below the permissible exposure limit, they shall
nonetheless be used to reduce exposures to the lowest levels achievable by
these controls and shall be supplemented by the use of respirators in accordance with paragraph (h) of this section and other necessary personal protective equipment. Employee rotation
is not required as a control strategy
before respiratory protection is instituted.
(2) Compliance Program. (i) The employer shall establish and implement a
written program to reduce exposures to
or below the permissible exposure limit
by means of engineering and work
practice controls.
(ii) Written plans for these compliance programs shall include at least
the following:
(A) A description of each operation in
which inorganic arsenic is emitted; e.g.
machinery used, material processed,
controls in place, crew size, operating
procedures and maintenance practices;
(B) Engineering plans and studies
used to determine methods selected for
controlling exposure to inorganic arsenic;
(C) A report of the technology considered in meeting the permissible exposure limit;
(D) Monitoring data;
(E) A detailed schedule for implementation of the engineering controls and
work practices that cannot be implemented immediately and for the
adaption and implementation of any
additional engineering and work prac-
§ 1910.1018
tices necessary to meet the permissible
exposure limit;
(F) Whenever the employer will not
achieve the permissible exposure limit
with engineering controls and work
practices by December 31, 1979, the employer shall include in the compliance
plan an analysis of the effectiveness of
the various controls, shall install engineering controls and institute work
practices on the quickest schedule feasible, and shall include in the compliance plan and implement a program to
minimize the discomfort and maximize
the effectiveness of respirator use; and
(G) Other relevant information.
(iii) Written plans for such a program
shall be submitted upon request to the
Assistant Secretary and the Director,
and shall be available at the worksite
for examination and copying by the Assistant Secretary, Director, any affected employee or authorized employee representatives.
(iv) The plans required by this paragraph shall be revised and updated at
least every 6 months to reflect the current status of the program.
(h) Respiratory protection—(1) General.
(i) Periods necessary to install or implement feasible engineering or workpractice controls.
(ii) Work operations, such as maintenance and repair activities, for which
the employer establishes that engineering and work-practice controls are not
feasible.
(iii) Work operations for which engineering and work-practice controls are
not yet sufficient to reduce employee
exposure limit.
(iv) Emergencies.
(ii) If an employee exhibits breathing
difficulty during fit testing or respirator use, they must be examined by
a physician trained in pulmonary medicine to determine whether they can use
85
§ 1910.1018
a respirator while performing the required duty.
(3) Respirator selection. (i) The employer must use Table I of this section
to select the appropriate respirator or
combination of respirators for inorganic arsenic compounds without significant vapor pressure, and Table II of
this section to select the appropriate
respirator or combination of respirators for inorganic arsenic compounds that have significant vapor
pressure.
(ii) When employee exposures exceed
the permissible exposure limit for inorganic arsenic and also exceed the rel-
evant limit for other gases (for example, sulfur dioxide), an air-purifying
respirator provided to the employee as
specified by this section must have a
combination high-efficiency filter with
an appropriate gas sorbent. (See footnote in Table 1 of this section.)
(iii) Employees required to use respirators may choose, and the employer
must provide, a powered air-purifying
respirator if it will provide proper protection. In addition, the employer must
provide a combination dust and acidgas respirator to employees who are exposed to gases over the relevant exposure limits.
TABLE I—RESPIRATORY PROTECTION FOR INORGANIC ARSENIC PARTICULATE EXCEPT FOR THOSE
WITH SIGNIFICANT VAPOR PRESSURE
Concentration of inorganic arsenic (as As)
or condition of use
Required respirator
(i) Unknown or greater or lesser than
20,000 µg/m(3) (20 mg/m(3)) or firefighting.
(ii) Not greater than 20,000 µg/m(3) (20
mg/m(3)).
(iii) Not greater than 10,000 µg/m(3) (10
mg/m(3)).
(A) Any full facepiece self-contained breathing apparatus operated in positive pressure mode.
(iv) Not greater than 500 µg/m(3) ...............
(v) Not greater than 100 µg/m(3) ................
1 High-efficiency
(A) Supplied air respirator with full facepiece, hood, or helmet or suit and operated
in positive pressure mode.
(A) Powered air-purifying respirators in all inlet face coverings with high efficiency
filters 1.
(B)Half-mask supplied air respirators operated in positive pressure mode.
(A) Full facepiece air-purifying respirator equipped with high-efficiency filter 1.
(B) Any full facepiece supplied air respirator.
(C) Any full facepiece self-contained breathing apparatus.
(A) Half-mask air-purifying respirator equipped with high-efficiency filter 1.
(B) Any half-mask supplied air respirator.
filter-99.97 pct efficiency against 0.3 micrometer monodisperse diethyl-hexyl phthalate (DOP) particles.
TABLE II—RESPIRATORY PROTECTION FOR INORGANIC ARSENICALS (SUCH AS ARSENIC
TRICHLORIDE 2 AND ARSENIC PHOSPHIDE) WITH SIGNIFICANT VAPOR PRESSURE
Concentration of inorganic arsenic (as As)
or condition of use
Required respirator
(i) Unknown or greater or lesser than
20,000 µg/m(3) (20 mg/m(3)) or firefighting.
(ii) Not greater than 20,000 µg/m(3) (20
mg/m(3)).
(iii) Not greater than 10,000 µg/m(3) (10
mg/m(3)).
(iv) Not greater than 500 µg/m(3) ...............
(A) Any full facepiece self-contained breathing apparatus operated in positive pressure mode.
(v) Not greater than 100 µg/m(3) ................
(A) Supplied air respirator with full facepiece, hood, or helmet or suit and operated
in positive pressure mode.
(A) Half-mask 2 supplied air respirator operated in positive pressure mode.
(A) Front or back mounted gas mask equipped with high-efficiency filter 1 and acid
gas canister.
(B) Any full facepiece supplied air respirator.
(C) Any full facepiece self-contained breathing apparatus.
(A) Half-mask air-purifying respirator equipped with high efficiency filter 1 and acid
gas cartridge.
(B) Any half-mask supplied air respirator.
1 High-efficiency
2 Half-mask
filter-99.97 pct efficiency against 0.3 micrometer monodisperse diethyl-hexyl phthalate (DOP) particles.
respirators shall not be used for protection against arsenic trichloride, as it is rapidly absorbed through the skin.
(i) [Reserved]
(j) Protective work clothing and equipment—(1) Provision and use. Where the
possibility of skin or eye irritation
from inorganic arsenic exists, and for
all workers working in regulated areas,
the employer shall provide at no cost
86
to the employee and assure that employees use appropriate and clean protective work clothing and equipment
such as, but not limited to:
work clothing;
(ii) Gloves, and shoes or coverlets;
(iii) Face shields or vented goggles
when necessary to prevent eye irritation, which comply with the requirements of § 1910.133(a) (2)–(6); and
(iv) Impervious clothing for employees subject to exposure to arsenic trichloride.
employer shall provide the protective
clothing required in paragraph (j) (1) of
this section in a freshly laundered and
dry condition at least weekly, and
daily if the employee works in areas
where exposures are over 100 µg/m3of
inorganic arsenic or in areas where
more frequent washing is needed to
prevent skin irritation.
(ii) The employer shall clean, launder, or dispose of protective clothing
required by paragraph (j) (1) of this section.
(iii) The employer shall repair or replace the protective clothing and
equipment as needed to maintain their
effectiveness.
(iv) The employer shall assure that
all protective clothing is removed at
the completion of a work shift only in
change rooms prescribed in paragraph
(m) (1) of this section.
(v) The employer shall assure that
contaminated
protective
clothing
which is to be cleaned, laundered, or
disposed of, is placed in a closed container in the change-room which prevents dispersion of inorganic arsenic
outside the container.
(vi) The employer shall inform in
writing any person who cleans or launders clothing required by this section,
of the potentially harmful effects including the carcinogenic effects of exposure to inorganic arsenic.
(vii) The employer shall assure that
the containers of contaminated protective clothing and equipment in the
workplace or which are to be removed
from the workplace are labelled as follows:
§ 1910.1018
ganic arsenic contaminated wash water
in accordance with applicable local,
State or Federal regulations.
(viii) The employer shall prohibit the
removal of inorganic arsenic from protective clothing or equipment by blowing or shaking.
(k) Housekeeping—(1) Surfaces. All
surfaces shall be maintained as free as
practicable of accumulations of inorganic arsenic.
(2) Cleaning floors. Floors and other
accessible surfaces contaminated with
inorganic arsenic may not be cleaned
by the use of compressed air, and shoveling and brushing may be used only
where vacuuming or other relevant
methods have been tried and found not
to be effective.
(3) Vacuuming. Where vacuuming
methods are selected, the vacuums
shall be used and emptied in a manner
to minimize the reentry of inorganic
arsenic into the workplace.
(4) Housekeeping plan. A written
housekeeping and maintenance plan
shall be kept which shall list appropriate frequencies for carrying out
housekeeping operations, and for cleaning and maintaining dust collection
equipment. The plan shall be available
for inspection by the Assistant Secretary.
(5) Maintenance of equipment. Periodic
cleaning of dust collection and ventilation equipment and checks of their effectiveness shall be carried out to
maintain the effectiveness of the system and a notation kept of the last
check of effectiveness and cleaning or
maintenance.
(l) [Reserved]
(m) Hygiene facilities and practices—(1)
Change rooms. The employer shall provide for employees working in regulated areas or subject to the possibility
of skin or eye irritation from inorganic
arsenic, clean change rooms equipped
with storage facilities for street
clothes and separate storage facilities
for protective clothing and equipment
in accordance with 29 CFR 1910.141(e).
(2) Showers. (i) The employer shall assure that employees working in regulated areas or subject to the possibility
of skin or eye irritation from inorganic
arsenic shower at the end of the work
shift.
CAUTION: Clothing contaminated with
inorganic arsenic; do not remove dust
by blowing or shaking. Dispose of inor-
87
§ 1910.1018
(ii) The employer shall provide shower facilities in accordance with
§ 1910.141(d)(3).
shall provide for employees working in
regulated areas, lunchroom facilities
which have a temperature controlled,
positive pressure, filtered air supply,
and which are readily accessible to employees working in regulated areas.
(ii) The employer shall assure that
employees working in the regulated
area or subject to the possibility of
skin or eye irritation from exposure to
inorganic arsenic wash their hands and
face prior to eating.
(4) Lavatories. The employer shall
provide lavatory facilities which comply with § 1910.141(d) (1) and (2).
(5) Vacuuming clothes. The employer
shall provide facilities for employees
working in areas where exposure, without regard to the use of respirators, exceeds 100 µg/m3to vacuum their protective clothing and clean or change shoes
worn in such areas before entering
change rooms, lunchrooms or shower
rooms required by paragraph (j) of this
section and shall assure that such employees use such facilities.
(6) Avoidance of skin irritation. The
employer shall assure that no employee is exposed to skin or eye contact with arsenic trichloride, or to skin
or eye contact with liquid or particulate inorganic arsenic which is likely
to cause skin or eye irritation.
(n) Medical surveillance—(1) General—
(i) Employees covered. The employer
shall institute a medical surveillance
program for the following employees:
(A) All employees who are or will be
exposed above the action level, without
regard to the use of respirators, at
least 30 days per year; and
(B) All employees who have been exposed above the action level, without
regard to respirator use, for 30 days or
more per year for a total of 10 years or
more of combined employment with
the employer or predecessor employers
prior to or after the effective date of
this standard. The determination of exposures prior to the effective date of
this standard shall be based upon prior
exposure records, comparison with the
first measurements taken after the effective date of this standard, or comparison with records of exposures in
areas with similar processes, extent of
engineering controls utilized and materials used by that employer.
(ii) Examination by physician. The employer shall assure that all medical examinations and procedures are performed by or under the supervision of a
licensed physician, and shall be provided without cost to the employee,
without loss of pay and at a reasonable
time and place.
(2) Initial examinations. By December
1, 1978, for employees initially covered
by the medical provisions of this section, or thereafter at the time of initial
assignment to an area where the employee is likely to be exposed over the
action level at least 30 days per year,
the employer shall provide each affected employee an opportunity for a
medical examination, including at
least the following elements:
(i) A work history and a medical history which shall include a smoking history and the presence and degree of
respiratory symptoms such as breathlessness, cough, sputum production and
wheezing.
(ii) A medical examination which
shall include at least the following:
(A) A 14″ by 17″ posterior-anterior
chest X-ray and International Labor
Office UICC/Cincinnati (ILO U/C) rating;
(B) A nasal and skin examination;
and
(C) Other examinations which the
physician believes appropriate because
of the employees exposure to inorganic
arsenic or because of required respirator use.
(3) Periodic examinations. (i) The employer shall provide the examinations
specified in paragraphs (n)(2)(i) and
(n)(2)(ii) at least annually for covered
employees who are under 45 years of
age with fewer than 10 years of exposure over the action level without regard to respirator use.
(ii) The employer shall provide the
examinations specified in paragraphs
(n)(2)(i) and (n)(2)(ii)(B) and (C) of this
section at least semiannually, and the
x-ray requirement specified in paragraph (n)(2)(ii)(A) of this section at
least annually, for other covered employees.
88
(iii) Whenever a covered employee
has not taken the examinations specified in paragraphs (n)(2)(i) and (n)(2)(ii)
of this section within six (6) months
preceding the termination of employment, the employer shall provide such
examinations to the employee upon
termination of employment.
(4) Additional examinations. If the employee for any reason develops signs or
symptoms commonly associated with
exposure to inorganic arsenic the employer shall provide an appropriate examination and emergency medical
treatment.
(i) A copy of this standard and its appendices;
employee’s exposure;
(iii) The employee’s representative
exposure level or anticipated exposure
level;
protective equipment used or to be
used; and
(v) Information from previous medical examinations of the affected employee which is not readily available to
the examining physician.
(6) Physician’s written opinion. (i) The
employer shall obtain a written opinion from the examining physician
which shall include:
(A) The results of the medical examination and tests performed;
(B) The physician’s opinion as to
medical conditions which would place
the employee at increased risk of material impairment of the employee’s
health from exposure to inorganic arsenic;
(C) Any recommended limitations
upon the employee’s exposure to inorganic arsenic or upon the use of protective clothing or equipment such as respirators; and
and any medical conditions which require further explanation or treatment.
(ii) The employer shall instruct the
physician not to reveal in the written
§ 1910.1018
opinion specific findings or diagnoses
unrelated to occupational exposure.
(iii) The employer shall provide a
copy of the written opinion to the affected employee.
(o) Employee information and training—(1) Training program. (i) The employer shall institute a training program for all employees who are subject
to exposure to inorganic arsenic above
the action level without regard to respirator use, or for whom there is the
possibility of skin or eye irritation
from inorganic arsenic. The employer
shall assure that those employees participate in the training program.
(ii) The training program shall be
provided by October 1, 1978, for employees covered by this provision, at the
time of initial assignment for those
subsequently covered by this provision,
and at least annually for other covered
employees thereafter; and the employer shall assure that each employee
is informed of the following:
(A) The information contained in Appendix A;
(B) The quantity, location, manner of
use, storage, sources of exposure, and
the specific nature of operations which
could result in exposure to inorganic
arsenic as well as any necessary protective steps;
(C) The purpose, proper use, and limitation of respirators;
(D) The purpose and a description of
the medical surveillance program as
required by paragraph (n) of this section;
(E) The engineering controls and
work practices associated with the employee’s job assignment; and
(F) A review of this standard.
(2) Access to training materials. (i) The
employer shall make readily available
to all affected employees a copy of this
standard and its appendices.
(ii) The employer shall provide; upon
and the Director.
(p) Signs and labels—(1) General. (i)
The employer may use labels or signs
required by other statutes, regulations,
or ordinances in addition to, or in combination with, signs and labels required
by this paragraph.
89
§ 1910.1018
(ii) The employer shall assure that no
statement appears on or near any sign
or label required by this paragraph
which contradicts or detracts from the
meaning of the required sign or label.
(2) Signs. (i) The employer shall post
signs demarcating regulated areas
bearing the legend;
mine representative employee exposure
where applicable;
(B) A description of the sampling and
analytical methods used and evidence
of their accuracy;
(C) The type of respiratory protective
devices worn, if any;
(D) Name, social security number,
and job classification of the employees
monitored and of all other employees
whose exposure the measurement is intended to represent; and
(E) The environmental variables that
could affect the measurement of the
employee’s exposure.
these monitoring records for at least 40
years or for the duration of employment plus 20 years, whichever, is
longer.
accurate record for each employee subject to medical surveillance as required
by paragraph (n) of this section.
(ii) This record shall include:
(A) The name, social security number, and description of duties of the
employee;
(B) A copy of the physician’s written
opinions;
(C) Results of any exposure monitoring done for that employee and the
representative exposure levels supplied
to the physician; and
(D) Any employee medical complaints related to exposure to inorganic
arsenic.
(iii) The employer shall in addition
keep, or assure that the examining
physician keeps, the following medical
records;
(A) A copy of the medical examination results including medical and
work history required under paragraph
(n) of this section;
(B) A description of the laboratory
procedures and a copy of any standards
or guidelines used to interpret the test
results or references to that information;
(C) The initial X-ray;
(D) The X-rays for the most recent 5
years; and
(E) Any X-rays with a demonstrated
abnormality and all subsequent X-rays;
(iv) The employer shall maintain or
assure that the physician maintains
those medical records for at least 40
DANGER
INORGANIC ARSENIC
CANCER HAZARD
NO SMOKING OR EATING
RESPIRATOR REQUIRED
signs required by this paragraph are illuminated and cleaned as necessary so
that the legend is readily visible.
(3) Labels. The employer shall apply
precautionary labels to all shipping
and storage containers of inorganic arsenic, and to all products containing
inorganic arsenic except when the inorganic arsenic in the product is bound in
such a manner so as to make unlikely
the possibility of airborne exposure to
inorganic arsenic. (Possible examples
of products not requiring labels are
semiconductors, light emitting diodes
and glass). The label shall bear the following legend:
DANGER
CONTAINS INORGANIC ARSENIC
CANCER HAZARD
HARMFUL IF INHALED OR
SWALLOWED
USE ONLY WITH ADEQUATE
VENITLATION
OR RESPIRATORY PROTECTION
(q) Recordkeeping—(1) Exposure monitoring. (i) The employer shall establish
and maintain an accurate record of all
monitoring required by paragraph (e)
of this section.
(A) The date(s), number, duration location, and results of each of the samples taken, including a description of
the sampling procedure used to deter-
90
years, or for the duration of employment plus 20 years whichever is longer.
(3) Availability. (i) The employer shall
make available upon request all
paragraph (q) of this section to the Assistant Secretary and the Director for
examination and copying.
(ii) Records required by this paragraph shall be provided upon request to
employees, designated representatives,
and (g) through (i).
(4) Transfer of records. (i) Whenever
the employer ceases to do business, the
successor employer shall receive and
retain all records required to be maintained by this section.
this section for the prescribed period,
these records shall be transmitted to
the Director.
(iii) At the expiration of the retention period for the records required to
be maintained by this section, the employer shall notify the Director at
least 3 months prior to the disposal of
such records and shall transmit those
records to the Director if he requests
them within that period.
(iv) The employer shall also comply
with any additional requirements involving the transfer of records set in 29
CFR 1910.20(h).
(r) Observation of monitoring—(1) Employee observation. The employer shall
employee exposure to inorganic arsenic
conducted pursuant to paragraph (e) of
this section.
(2) Observation procedures. (i) Whenever observation of the monitoring of
employee exposure to inorganic arsenic
requires entry into an area where the
use of respirators, protective clothing,
or equipment is required, the employer
shall provide the observer with and assure the use of such respirators, clothing, and such equipment, and shall require the observer to comply with all
other applicable safety and health procedures.
§ 1910.1018
(ii) Without interfering with the
monitoring, observers shall be entitled
to;
(A) Receive an explanation of the
measurement procedures;
(B) Observe all steps related to the
monitoring of inorganic arsenic performed at the place of exposure; and
(C) Record the results obtained or receive copies of the results when returned by the laboratory.
(s) Effective date. This standard shall
become effective August 1, 1978.
(t) Appendices. The information contained in the appendices to this section
is not intended by itself, to create any
additional obligations not otherwise
imposed by this standard nor detract
from any existing obligation.
(u) Startup dates—(1) General. The
startup dates of requirements of this
standard shall be the effective date of
this standard unless another startup
date is provided for either in other
paragraphs of this section or in this
paragraph.
(2) Monitoring. Initial monitoring
shall be commenced on August 1, 1978,
and shall be completed by September
15, 1978.
(3) Regulated areas. Regulated areas
required to be established as a result of
initial monitoring shall be set up as
soon as possible after the results of
that monitoring is known and no later
than October 1, 1978.
(4) Compliance program. The written
program required by paragraph (g)(2) as
a result of initial monitoring shall be
made available for inspection and
copying as soon as possible and no
later than December 1, 1978.
(5) Hygiene and lunchroom facilities.
Construction plans for change- rooms,
showers, lavatories, and lunchroom facilities shall be completed no later
than December 1, 1978, and these facilities shall be constructed and in use no
later than July 1, 1979. However, if as
part of the compliance plan it is predicted by an independent engineering
firm that engineering controls and
work practices will reduce exposures
below the permissible exposure limit
by December 31, 1979, for affected employees, then such facilities need not
be completed until 1 year after the engineering controls are completed or
December 31, 1980, whichever is earlier,
91
§ 1910.1018
III. PROTECTIVE CLOTHING AND EQUIPMENT
if such controls have not in fact succeeded in reducing exposure to below
the permissible exposure limit.
(6) Summary of startup dates set forth
elsewhere in this standard.
A. Respirators. Respirators will be provided
by your employer at no cost to you for routine use if your employer is in the process of
implementing engineering and work practice
controls or where engineering and work
practice controls are not feasible or insufficient. You must wear respirators for nonroutine activities or in emergency situations
where you are likely to be exposed to levels
of inorganic arsenic in excess of the permissible exposure limit. Since how well your
respirator fits your face is very important,
your employer is required to conduct fit
tests to make sure the respirator seals properly when you wear it. These tests are simple
and rapid and will be explained to you during
training sessions.
B. Protective clothing. If you work in a regulated area, your employer is required to provide at no cost to you, and you must wear,
appropriate, clean, protective clothing and
equipment. The purpose of this equipment is
to prevent you from bringing to your home
arsenic-contaminated dust and to protect
your body from repeated skin contact with
inorganic arsenic likely to cause skin irritation. This clothing should include such items
as coveralls or similar full-body clothing,
gloves, shoes or coverlets, and aprons. Protective equipment should include face
shields or vented goggles, where eye irritation may occur. y
STARTUP DATES
August 1, 1978—Respirator use over 500 µg/m3.
AS SOON AS POSSIBLE BUT NO LATER THAN
September 15, 1978—Completion of initial
monitoring.
October 1, 1978—Complete establishment of
regulated areas. Respirator use for employees exposed above 50 µg/m3. Completion of
initial training. Notification of use.
December 1, 1978—Respirator use over 10 µg/
m3. Completion of initial medical. Completion of compliance plan. Optional use of
powered air-purifying respirators.
July 1, 1979—Completion of lunch rooms and
hygiene facilities.
December 31, 1979—Completion of engineering controls.
All other requirements of the standard have
as their startup date August 1, 1978.
APPENDIX A TO § 1910.1018—INORGANIC
ARSENIC SUBSTANCE INFORMATION
SHEET
I. SUBSTANCE IDENTIFICATION
IV. HYGIENE FACILITIES AND PRACTICES
A. Substance. Inorganic Arsenic.
B. Definition. Copper acetoarsenite, arsenic
and all inorganic compounds containing arsenic except arsine, measured as arsenic
(As).
C. Permissible Exposure Limit. 10 micrograms
per cubic meter of air as determined as an
average over an 8-hour period. No employee
may be exposed to any skin or eye contact
with arsenic trichloride or to skin or eye
contact likely to cause skin or eye irritation.
D. Regulated Areas. Only employees authorized by your employer should enter a regulated area.
You must not eat, drink, smoke, chew gum
or tobacco, or apply cosmetics in the regulated area, except that drinking water is permitted. If you work in a regulated area your
employer is required to provide lunchrooms
and other areas for these purposes.
If you work in a regulated area, your employer is required to provide showers, washing facilities, and change rooms. You must
wash your face, and hands before eating and
must shower at the end of the work shift. Do
not take used protective clothing out of
change rooms without your employer’s permission. Your employer is required to provide for laundering or cleaning of your protective clothing.
II. HEALTH HAZARD DATA
V. SIGNS AND LABELS
A. Comments. The health hazard of inorganic arsenic is high.
B. Ways in which the chemical affects your
body. Exposure to airborne concentrations of
inorganic arsenic may cause lung cancer,
and can be a skin irritant. Inorganic arsenic
may also affect your body if swallowed. One
compound in particular, arsenic trichloride,
is especially dangerous because it can be absorbed readily through the skin. Because inorganic arsenic is a poison, you should wash
your hands thoroughly prior to eating or
smoking.
Your employer is required to post warning
signs and labels for your protection. Signs
must be posted in regulated areas. The signs
must warn that a cancer hazard is present,
that only authorized employees may enter
the area, and that no smoking or eating is
allowed, and that respirators must be worn.
VI. MEDICAL EXAMINATIONS
If your exposure to arsenic is over the Action Level (5 mg/m3)—(including all persons
working in regulated areas) at least 30 days
per year, or you have been exposed to arsenic
92
for more than 10 years over the Action Level,
your employer is required to provide you
with a medical examination. The examination shall be every 6 months for employees
over 45 years old or with more than 10 years
exposure over the Action Level and annually
for other covered employees. The medical examination must include a medical history; a
chest x-ray; a skin examination and a nasal
examination. The examining physician will
provide a written opinion to your employer
containing the results of your medical
exams. You should also receive a copy of this
opinion. The physician must not tell your
employer any conditions he detects unrelated to occupational exposure to arsenic but
must tell you those conditions.
§ 1910.1018
3. Melting point: 315C.
4. Specific Gravity (H20=1):3.74.
5. Solubility in water: 3.7 grams in 100cc of
water at 20c.
C. Arsenic Trichloride (liquid).
1. Formula: AsC13.
2. Appearance: Colorless or pale yellow liquid.
3. Melting point: ¥8.5C.
4. Boiling point: 130.2C.
5. Specific Gravity (H20=1):2.16 at 20C.
6. Vapor Pressure: 10mm Hg at 23.5C.
7. Solubility in Water: Decomposes in
water.
II. Fire, explosion and reactivity data.
A. Fire: Arsenic, arsenic Trioxide and Arsenic Trichloride are nonflammable.
B. Reactivity:
1. Conditions Contributing to instability:
Heat.
2. Incompatibility: Hydrogen gas can react
with inorganic arsenic to form the highly
toxic gas arsine.
VII. OBSERVATION OF MONITORING
Your employer is required to monitor your
exposure to arsenic and you or your representatives are entitled to observe the monitoring procedure. You are entitled to receive an explanation of the measurement
procedure, and to record the results obtained. When the monitoring procedure is
taking place in an area where respirators or
personal protective clothing and equipment
are required to be worn, you must also be
provided with and must wear the protective
clothing and equipment.
III. Monitoring and Measurement Procedures
Samples collected should be full shift (at
least 7-hour) samples. Sampling should be
done using a personal sampling pump at a
flow rate of 2 liters per minute. Samples
should be collected on 0.8 micrometer pore
size membrane filter (37mm diameter). Volatile arsenicals such as arsenic trichloride
can be most easily collected in a midget bubbler filled with 15 ml. of 0.1 N NaOH.
The method of sampling and analysis
should have an accuracy of not less than ±25
percent (with a confidence limit of 95 percent) for 10 micrograms per cubic meter of
air (10 µg/m3) and ±35 percent (with a confidence limit of 95 percent) for concentrations of inorganic arsenic between 5 and 10
µg/m3.
VIII. ACCESS TO RECORDS
You or your representative are entitled to
records of your exposure to inorganic arsenic
and your medical examination records if you
request your employer to provide them.
IX. TRAINING AND NOTIFICATION
Additional information on all of these
items plus training as to hazards of exposure
to inorganic arsenic and the engineering and
work practice controls associated with your
job will also be provided by your employer. If
you are exposed over the permissible exposure limit, your employer must inform you
of that fact and the actions he is taking to
reduce your exposures.
APPENDIX C TO § 1910.1018—MEDICAL
SURVEILLANCE GUIDELINES
I. GENERAL
Medical examinations are to be provided
for all employees exposed to levels of inorganic arsenic above the action level (5 µg/m3)
for at least 30 days per year (which would include among others, all employees, who work
in regulated areas). Examinations are also to
be provided to all employees who have had 10
years or more exposure above the action
level for more than 30 days per year while
working for the present or predecessor employer though they may no longer be exposed
above the level.
An initial medical examination is to be
provided to all such employees by December
1, 1978. In addition, an initial medical examination is to be provided to all employees
who are first assigned to areas in which
worker exposure will probably exceed 5 µg/
APPENDIX B TO § 1910.1018—SUBSTANCE
TECHNICAL GUIDELINES
ARSENIC, ARSENIC TRIOXIDE, ARSENIC
TRICHLORIDE (THREE EXAMPLES)
I. Physical and chemical properties
A. Arsenic (metal).
1. Formula: As.
2. Appearance: Gray metal.
3. Melting point: Sublimes without melting
at 613C.
4. Specific Gravity: (H20=1):5.73.
5. Solubility in water: Insoluble.
B. Arsenic Trioxide.
1. Formula: As203, (As406).
2. Appearance: White powder.
93
§ 1910.1018
m3(after the effective date of this standard)
at the time of initial assignment. In addition
to its immediate diagnostic usefulness, the
initial examination will provide a baseline
for comparing future test results. The initial
examination must include as a minimum the
following elements:
(1) A work and medical history, including a
smoking history, and presence and degree of
respiratory symptoms such as breathlessness, cough, sputum production, and wheezing;
(2) A 14″ by 17″ posterior-anterior chest Xray and an International Labor Office UICC/
Cincinnati (ILO U/C) rating;
(3) A nasal and skin examination; and
(4) Other examinations which the physician believes appropriate because of the employee’s exposure to inorganic arsenic or because of required respirator use.
Periodic examinations are also to be provided to the employees listed above. The
periodic examinations shall be given annually for those covered employees 45 years of
age or less with fewer than 10 years employment in areas where employee exposure exceeds the action level (5 µg/m3). Periodic examinations need not include sputum cytology and only an updated medical history is
required.
Periodic examinations for other covered
employees, shall be provided every six (6)
months. These examinations shall include
all tests required in the initial examination,
except that the medical history need only be
updated.
The examination contents are minimum
requirements. Additional tests such as lateral and oblique X-rays or pulmonary function tests may be useful. For workers exposed to three arsenicals which are associated
with
lymphatic
cancer,
copper
acetoarsenite, potassium arsenite, or sodium
arsenite the examination should also include
palpation of superficial lymph nodes and
complete blood count.
tion. Conjunctiva, moist and macerated
areas of skin, the eyelids, the angles of the
ears, nose, mouth, and respiratory mucosa
are also vulnerable to the irritant effects.
The wrists are common sites of dermatitis,
as are the genitalia if personal hygiene is
poor. Perforations of the nasal septum may
occur. Arsenic trioxide and pentoxide are capable of producing skin sensitization and
contact dermatitis. Arsenic is also capable of
producing keratoses, especially of the palms
and soles.
B. Systemic— The acute toxic effects of arsenic are generally seen following ingestion
of inorganic arsenical compounds. This rarely occurs in an industrial setting. Symptoms
develop within 1⁄2 to 4 hours following ingestion and are usually characterized by constriction of the throat followed by dysphagia, epigastric pain, vomiting, and watery diarrhea. Blood may appear in vomitus
and stools. If the amount ingested is sufficiently high, shock may develop due to severe fluid loss, and death may ensue in 24
hours. If the acute effects are survived,
exfoliative dermatitis and peripheral neuritis may develop.
Cases of acute arsenical poisoning due to
inhalation are exceedingly rare in industry.
When it does occur, respiratory tract symptoms—cough, chest pain, dyspnea—giddiness,
headache, and extreme general weakness
precede gastrointestinal symptoms. The
acute toxic symptoms of trivalent arsenical
poisoning are due to severe inflammation of
the mucous membranes and greatly increased permeability of the blood capillaries.
Chronic arsenical poisoning due to ingestion is rare and generally confined to patients taking prescribed medications. However, it can be a concomitant of inhaled inorganic arsenic from swallowed sputum and
improper eating habits. Symptoms are
weight loss, nausea and diarrhea alternating
with constipation, pigmentation and eruption of the skin, loss of hair, and peripheral
neuritis. Chronic hepatitis and cirrhosis
have been described. Polyneuritis may be the
salient feature, but more frequently there
are numbness and parasthenias of ‘‘glove and
stocking’’ distribution. The skin lesions are
usually melanotic and keratotic and may occasionally take the form of an intradermal
cancer of the squamous cell type, but without infiltrative properties. Horizontal white
lines (striations) on the fingernails and toenails are commonly seen in chronic arsenical
poisoning and are considered to be a diagnostic
accompaniment
of
arsenical
polyneuritis.
Inhalation of inorganic arsenic compounds
is the most common cause of chronic poisoning in the industrial situation. This condition is divided into three phases based on
signs and symptoms.
II. NONCARCINOGENIC EFFECTS
The OSHA standard is based on minimizing
risk of exposed workers dying of lung cancer
from exposure to inorganic arsenic. It will
also minimize skin cancer from such exposures.
The following three sections quoted from
‘‘Occupational Diseases: A Guide to Their
Recognition’’, Revised Edition, June 1977,
National Institute for Occupational Safety
and Health is included to provide information on the nonneoplastic effects of exposure
to inorganic arsenic. Such effects should not
occur if the OSHA standards are followed.
A. Local— Trivalent arsenic compounds are
corrosive to the skin. Brief contact has no
effect but prolonged contact results in a
local hyperemia and later vesicular or
pustular eruption. The moist mucous membranes are most sensitive to the irritant ac-
94
§ 1910.1020
Vallee, B. L., D. D. Ulmer, and W. E. C.
Wacker. 1960. Arsenic toxicology and biochemistry. AMA Arch. Indust. Health 21:132.
First Phase: The worker complains of
weakness, loss of appetite, some nausea, occasional vomiting, a sense of heaviness in
the stomach, and some diarrhea.
Second Phase: The worker complains of
conjunctivitis, a catarrhal state of the mucous membranes of the nose, larynx, and respiratory passage. Coryza, hoarseness, and
mild tracheobronchitis may occur. Perforation of the nasal septum is common, and is
probably the most typical lesion of the upper
respiratory tract in occupational exposure to
arsenical dust. Skin lesions, eczematoid and
allergic in type, are common.
Third Phase: The worker complains of
symptoms of peripheral neuritis, initially of
hands and feet, which is essentially sensory.
In more severe cases, motor paralyses occur;
the first muscles affected are usually the toe
extensors and the peronei. In only the most
severe cases will paralysis of flexor muscles
of the feet or of the extensor muscles of
hands occur.
Liver damage from chronic arsenical poisoning is still debated, and as yet the question is unanswered. In cases of chronic and
acute arsenical poisoning, toxic effects to
the myocardium have been reported based on
EKG changes. These findings, however, are
now largely discounted and the EKG changes
are ascribed to electrolyte disturbances concomitant with arsenicalism. Inhalation of
arsenic trioxide and other inorganic arsenical dusts does not give rise to radiological
evidence or pneumoconiosis. Arsenic does
have a depressant effect upon the bone marrow,
with
disturbances
of
both
erythropoiesis and myelopoiesis.
[39 FR 23502, June 27, 1974, as amended at 43
FR 19624, May 5, 1978; 43 FR 28472, June 30,
1978; 45 FR 35282, May 23, 1980; 54 FR 24334,
June 7, 1989; 58 FR 35310, June 30, 1993; 61 FR
5508, Feb. 13, 1996; 61 FR 9245, Mar. 7, 1996; 63
FR 1286, Jan. 8, 1998; 63 FR 33468, June 18,
1998]
§ 1910.1020 Access to employee exposure and medical records.
(a) Purpose. The purpose of this section is to provide employees and their
designated representatives a right of
access to relevant exposure and medical records; and to provide representatives of the Assistant Secretary a right
of access to these records in order to
fulfill responsibilities under the Occupational Safety and Health Act. Access
by employees, their representatives,
and the Assistant Secretary is necessary to yield both direct and indirect
improvements in the detection, treatment, and prevention of occupational
disease. Each employer is responsible
for assuring compliance with this section, but the activities involved in
complying with the access to medical
records provisions can be carried out,
on behalf of the employer, by the physician or other health care personnel in
charge of employee medical records.
Except as expressly provided, nothing
in this section is intended to affect existing legal and ethical obligations
concerning the maintenance and confidentiality of employee medical information, the duty to disclose information to a patient/employee or any other
aspect of the medical-care relationship,
or affect existing legal obligations concerning the protection of trade secret
information.
(b) Scope and application. (1) This section applies to each general industry,
maritime, and construction employer
who makes, maintains, contracts for,
or has access to employee exposure or
medical records, or analyses thereof,
pertaining to employees exposed to
toxic substances or harmful physical
agents.
BIBLIOGRAPHY
Dinman, B. D. 1960. Arsenic; chronic
human intoxication. J. Occup. Med. 2:137.
Elkins, H. B. 1959. The Chemistry of Industrial Toxicology, 2nd ed. John Wiley and
Sons, New York.
Holmquist, L. 1951. Occupational arsenical
dermatitis; a study among employees at a
copper-ore smelting works including investigations of skin reactions to contact with
arsenic compounds. Acta. Derm. Venereol.
(Supp. 26) 31:1.
Pinto, S. S., and C. M. McGill. 1953. Arsenic
trioxide exposure in industry. Ind. Med.
Surg. 22:281.
Pinto, S. S., and K. W. Nelson. 1976. Arsenic toxicology and industrial exposure.
Annu. Rev. Pharmacol. Toxicol. 16:95.
95
§ 1910.1020
(2) This section applies to all employee exposure and medical records,
and analyses thereof, of such employees, whether or not the records are
mandated by specific occupational
safety and health standards.
(3) This section applies to all employee exposure and medical records,
and analyses thereof, made or maintained in any manner, including on an
in-house of contractual (e.g., fee-forservice) basis. Each employer shall assure that the preservation and access
requirements of this section are complied with regardless of the manner in
which the records are made or maintained.
(c) Definitions. (1) Access means the
right and opportunity to examine and
copy.
(2) Analysis using exposure or medical
records means any compilation of data
or any statistical study based at least
in part on information collected from
individual employee exposure or medical records or information collected
from health insurance claims records,
provided that either the analysis has
been reported to the employer or no
further work is currently being done by
the person responsible for preparing
the analysis.
(3) Designated representative means
any individual or organization to
whom an employee gives written authorization to exercise a right of access. For the purposes of access to employee exposure records and analyses
using exposure or medical records, a
recognized or certified collective bargaining agent shall be treated automatically as a designated representative without regard to written employee authorization.
(4) Employee means a current employee, a former employee, or an employee being assigned or transferred to
work where there will be exposure to
agents. In the case of a deceased or legally incapacitated employee, the employee’s legal representative may directly exercise all the employee’s
rights under this section.
(5) Employee exposure record means a
record containing any of the following
kinds of information:
(i) Environmental (workplace) monitoring or measuring of a toxic sub-
stance or harmful physical agent, including personal, area, grab, wipe, or
other form of sampling, as well as related collection and analytical methodologies, calculations, and other
background data relevant to interpretation of the results obtained;
(ii) Biological monitoring results
which directly assess the absorption of
a toxic substance or harmful physical
agent by body systems (e.g., the level
of a chemical in the blood, urine,
breath, hair, fingernails, etc) but not
including results which assess the biological effect of a substance or agent or
which assess an employee’s use of alcohol or drugs;
(iii) Material safety data sheets indicating that the material may pose a
hazard to human health; or
(iv) In the absence of the above, a
chemcial inventory or any other record
which reveals where and when used and
the identity (e.g., chemical, common,
or trade name) of a toxic substance or
harmful physical agent.
(6)(i) Employee medical record means a
record concerning the health status of
an employee which is made or maintained by a physician, nurse, or other
health care personnel or technician, including:
(A) Medical and employment questionnaires or histories (including job
description and occupational exposures),
(B) The results of medical examinations
(pre-employment,
pre-assignment, periodic, or episodic) and laboratory tests (including chest and other
X–ray examinations taken for the purposes of establishing a base-line or detecting occupational illness, and all biological monitoring not defined as an
‘‘employee exposure record’’),
(C) Medical opinions, diagnoses,
progress notes, and recommendations,
(D) First aid records,
(E) Descriptions of treatments and
prescriptions, and
(F) Employee medical complaints.
(ii) ‘‘Employee medical record’’ does
not include medical information in the
form of:
(A) Physical specimens (e.g., blood or
urine samples) which are routinely discarded as a part of normal medical
practice; or
96
(B) Records concerning health insurance claims if maintained separately
from the employer’s medical program
and its records, and not accessible to
the employer by employee name or
other direct personal identifier (e.g.,
social security number, payroll number, etc.); or
(C) Records created solely in preparation for litigation which are privileged
from discovery under the applicable
rules of procedure or evidence; or
(D) Records concerning voluntary
employee assistance programs (alcohol,
drug abuse, or personal counseling programs) if maintained separately from
the employer’s medical program and
its records.
(7) Employer means a current employer, a former employer, or a successor employer.
(8) Exposure or exposed means that an
employee is subjected to a toxic substance or harmful physical agent in the
course of employment through any
route of entry (inhalation, ingestion,
skin contact or absorption, etc.), and
includes past exposure and potential
(e.g., accidental or possible) exposure,
but does not include situations where
the employer can demonstrate that the
toxic substance or harmful physical
agent is not used, handled, stored, generated, or present in the workplace in
any manner different from typical nonoccupational situations.
(9) Health Professional means a physician, occupational health nurse, industrial hygienist, toxicologist, or epidemiologist, providing medical or
other occupational health services to
exposed employees.
(10) Record means any item, collection, or grouping of information regardless of the form or process by
which it is maintained (e.g., paper document, microfiche, microfilm, X-ray
film, or automated data processing).
(11) Specific chemical identity means
the chemical name, Chemical Abstracts Service (CAS) Registry Number, or any other information that reveals the precise chemical designation
of the substance.
(12)(i) Specific written consent means a
written authorization containing the
following:
§ 1910.1020
(A) The name and signature of the
employee authorizing the release of
medical information,
(B) The date of the written authorization,
(C) The name of the individual or organization that is authorized to release
the medical information,
(D) The name of the designated representative (individual or organization)
that is authorized to receive the released information,
(E) A general description of the medical information that is authorized to
be released,
(F) A general description of the purpose for the release of the medical information, and
(G) A date or condition upon which
the written authorization will expire
(if less than one year).
(ii) A written authorization does not
operate to authorize the release of
medical information not in existence
on the date of written authorization,
unless the release of future information is expressly authorized, and does
not operate for more than one year
from the date of written authorization.
(iii) A written authorization may be
revoked in writing prospectively at any
time.
(13) Toxic substance or harmful physical agent means any chemical substance, biological agent (bacteria,
virus, fungus, etc.), or physical stress
(noise, heat, cold, vibration, repetitive
motion, ionizing and non-ionizing radiation, hypo-or hyperbaric pressure,
etc.) which:
(i) Is listed in the latest printed edition of the National Institute for Occupational Safety and Health (NIOSH)
Registry of Toxic Effects of Chemical
Substances (RTECS), which is incorporated by reference as specified in
§ 1910.6; or
(ii) Has yielded positive evidence of
an acute or chronic health hazard in
testing conducted by, or known to, the
employer; or
(iii) Is the subject of a material safety data sheet kept by or known to the
employer indicating that the material
may pose a hazard to human health.
(14) Trade secret means any confidential formula, pattern, process, device,
or information or compilation of information that is used in an employer’s
97
§ 1910.1020
business and that gives the employer
an opportunity to obtain an advantage
over competitors who do not know or
use it.
(d) Preservation of records. (1) Unless a
specific occupational safety and health
standard provides a different period of
time, each employer shall assure the
preservation and retention of records
as follows:
(i) Employee medical records. The medical record for each employee shall be
preserved and maintained for at least
the duration of employment plus thirty
(30) years, except that the following
types of records need not be retained
for any specified period:
(A) Health insurance claims records
maintained separately from the employer’s medical program and its
records,
(B) First aid records (not including
medical histories) of one-time treatment and subsequent observation of
minor scratches, cuts, burns, splinters,
and the like which do not involve medical treatment, loss of consciousness,
restriction of work or motion, or transfer to another job, if made on-site by a
non-physician and if maintained separately from the employer’s medical
program and its records, and
(C) The medical records of employees
who have worked for less than (1) year
for the employer need not be retained
beyond the term of employment if they
are provided to the employee upon the
termination of employment.
(ii) Employee exposure records. Each
employee exposure record shall be preserved and maintained for at least thirty (30) years, except that:
(A) Background data to environmental (workplace) monitoring or
measuring, such as laboratory reports
and worksheets, need only be retained
for one (1) year as long as the sampling
results, the collection methodology
(sampling plan), a description of the
analytical and mathematical methods
used, and a summary of other background data relevant to interpretation
of the results obtained, are retained for
at least thirty (30) years; and
(B) Material safety data sheets and
paragraph (c)(5)(iv) records concerning
the identity of a substance or agent
need not be retained for any specified
period as long as some record of the
identity (chemical name if known) of
the substance or agent, where it was
used, and when it was used is retained
for at least thirty (30) years;1 and
(C) Biological monitoring results designated as exposure records by specific
occupational safety and health standards shall be preserved and maintained
as required by the specific standard.
(iii) Analyses using exposure or medical
records. Each analysis using exposure
or medial records shall be preserved
and maintained for at least thirty (30)
years.
(2) Nothing in this section is intended
to mandate the form, manner, or process by which an employer preserves a
record as long as the information contained in the record is preserved and
retrievable, except that chest X-ray
films shall be preserved in their original state.
(e) Access to records—(1) General. (i)
Whenever an employee or designated
representative requests access to a
record, the employer shall assure that
access is provided in a reasonable time,
place, and manner. If the employer
cannot reasonably provide access to
the record within fifteen (15) working
days, the employer shall within the fifteen (15) working days apprise the employee or designated representative requesting the record of the reason for
the delay and the earliest date when
the record can be made available.
(ii) The employer may require of the
requester only such information as
should be readily known to the requester and which may be necessary to
locate or identify the records being requested (e.g. dates and locations where
the employee worked during the time
period in question).
(iii) Whenever an employee or designated representative requests a copy
of a record, the employer shall assure
that either:
(A) A copy of the record is provided
without cost to the employee or representative,
(B) The necessary mechanical copying facilities (e.g., photocopying) are
1 Material safety data sheets must be kept
for those chemicals currently in use that are
effected by the Hazard Communication
Standard in accordance with 29 CFR
1910.1200(g).
98
made available without cost to the employee or representative for copying
the record, or
(C) The record is loaned to the employee or representative for a reasonable time to enable a copy to be made.
(iv) In the case of an original X-ray,
the employer may restrict access to
on-site examination or make other
suitable arrangements for the temporary loan of the X-ray.
(v) Whenever a record has been previously provided without cost to an
employee or designated representative,
the employer may charge reasonable,
non-discriminatory
administrative
costs (i.e., search and copying expenses
but not including overhead expenses)
for a request by the employee or designated representative for additional
copies of the record, except that
(A) An employer shall not charge for
an initial request for a copy of new information that has been added to a
record which was previously provided;
and
(B) An employer shall not charge for
an initial request by a recognized or
certified collective bargaining agent
for a copy of an employee exposure
record or an analysis using exposure or
medical records.
(vi) Nothing in this section is intended to preclude employees and collective bargaining agents from collectively bargaining to obtain access to
information in addition to that available under this section.
(2) Employee and designated representative
access—(i)
Employee
exposure
records. (A) Except as limited by paragraph (f) of this section, each employer
shall, upon request, assure the access
to each employee and designated representative to employee exposure
records relevant to the employee. For
the purpose of this section, an exposure
record relevant to the employee consists of:
(1) A record which measures or monitors the amount of a toxic substance
or harmful physical agent to which the
employee is or has been exposed;
(2) In the absence of such directly relevant records, such records of other
employees with past or present job duties or working conditions related to or
similar to those of the employee to the
extent necessary to reasonably indi-
§ 1910.1020
cate the amount and nature of the
agents to which the employee is or has
been subjected, and
(3) Exposure records to the extent
necessary to reasonably indicate the
amount and nature of the toxic substances or harmful physical agents at
workplaces or under working conditions to which the employee is being
assigned or transferred.
(B) Requests by designated representatives for unconsented access to employee exposure records shall be in
writing and shall specify with reasonable particularity:
(1) The records requested to be disclosed; and
(2) The occupational health need for
gaining access to these records.
(ii) Employee medical records. (A) Each
employer shall, upon request, assure
the access of each employee to employee medical records of which the
employee is the subject, except as provided in paragraph (e)(2)(ii)(D) of this
section.
(B) Each employer shall, upon request, assure the access of each designated representative to the employee
medical records of any employee who
has given the designated representative
specific written consent. Appendix A to
this section contains a sample form
which may be used to establish specific
written consent for access to employee
medical records.
(C) Whenever access to employee
medical records is requested, a physician representing the employer may
recommend that the employee or designated representative:
(1) Consult with the physician for the
purposes of reviewing and discussing
the records requested,
(2) Accept a summary of material
facts and opinions in lieu of the records
requested, or
(3) Accept release of the requested
records only to a physician or other
designated representative.
(D) Whenever an employee requests
access to his or her employee medical
records, and a physician representing
the employer believes that direct employee access to information contained
in the records regarding a specific diagnosis of a terminal illness or a psychiatric condition could be detrimental
99
§ 1910.1020
to the employee’s health, the employer
may inform the employee that access
will only be provided to a designated
representative of the employee having
specific written consent, and deny the
employee’s request for direct access to
this information only. Where a designated representative with specific
written consent requests access to information so withheld, the employer
shall assure the access of the designated representative to this information, even when it is known that the
designated representative will give the
information to the employee.
(E) A physician, nurse, or other responsible health care personnel maintaining medical records may delete
from requested medical records the
identity of a family member, personal
friend, or fellow employee who has provided confidential information concerning an employee’s health status.
(iii) Analyses using exposure or medical
records. (A) Each employee shall, upon
request, assure the access of each employee and designated representative
to each analysis using exposure or
medical records concerning the employee’s working conditions or workplace.
(B) Whenever access is requested to
an analysis which reports the contents
of employee medical records by either
direct identifier (name, address, social
security number, payroll number, etc.)
or by information which could reasonably be used under the circumstances
indirectly to identify specific employees (exact age, height, weight, race,
sex, date of initial employment, job
title, etc.), the employer shall assure
that personal identifiers are removed
before access is provided. If the employer can demonstrate that removal
of personal identifiers from an analysis
is not feasible, access to the personally
identifiable portions of the analysis
need not be provided.
(3) OSHA access. (i) Each employer
shall, upon request, and without derogation of any rights under the Constitution or the Occupational Safety
and Health Act of 1970, 29 U.S.C. 651 et
seq., that the employer chooses to exercise, assure the prompt access of representatives of the Assistant Secretary
of Labor for Occupational Safety and
Health to employee exposure and med-
ical records and to analyses using exposure or medical records. Rules of agency practice and procedure governing
OSHA access to employee medical
records are contained in 29 CFR 1913.10.
(ii) Whenever OSHA seeks access to
personally identifiable employee medical information by presenting to the
employer a written access order pursuant to 29 CFR 1913.10(d), the employer
shall prominently post a copy of the
written access order and its accompanying cover letter for at least fifteen
(15) working days.
(f) Trade secrets. (1) Except as provided in paragraph (f)(2) of this section,
nothing in this section precludes an
employer from deleting from records
requested by a health professional, employee, or designated representative
any trade secret data which discloses
manufacturing processes, or discloses
the percentage of a chemical substance
in mixture, as long as the health professional, employee, or designated representative is notified that information
has been deleted. Whenever deletion of
trade secret information substantially
impairs evaluation of the place where
or the time when exposure to a toxic
substance or harmful physical agent
occurred, the employer shall provide
alternative information which is sufficient to permit the requesting party to
identify where and when exposure occurred.
(2) The employer may withhold the
specific chemical identity, including
the chemical name and other specific
identification of a toxic substance from
a disclosable record provided that:
(i) The claim that the information
withheld is a trade secret can be supported;
(ii) All other available information
on the properties and effects of the
toxic substance is disclosed;
(iii) The employer informs the requesting party that the specific chemical identity is being withheld as a
trade secret; and
(iv) The specific chemical identity is
made available to health professionals,
employees and designated representatives in accordance with the specific
applicable provisions of this paragraph.
(3) Where a treating physician or
nurse determines that a medical emergency exists and the specific chemical
100
identity of a toxic substance is necessary for emergency or first-aid treatment, the employer shall immediately
disclose the specific chemical identity
of a trade secret chemical to the treating physician or nurse, regardless of
the existence of a written statement of
need or a confidentiality agreement.
The employer may require a written
statement of need and confidentiality
agreement, in accordance with the provisions of paragraphs (f)(4) and (f)(5), as
soon as circumstances permit.
(4) In non-emergency situations, an
employer shall, upon request, disclose
a specific chemical identity, otherwise
permitted to be withheld under paragraph (f)(2) of this section, to a health
professional, employee, or designated
representative if:
(i) The request is in writing;
(ii) The request describes with reasonable detail one or more of the following occupational health needs for
the information:
(A) To assess the hazards of the
chemicals to which employees will be
exposed;
(B) To conduct or assess sampling of
the workplace atmosphere to determine employee exposure levels;
(C) To conduct pre-assignment or
periodic medical surveillance of exposed employees;
(D) To provide medical treatment to
exposed employees;
(E) To select or assess appropriate
personal protective equipment for exposed employees;
(F) To design or assess engineering
controls or other protective measures
for exposed employees; and
(G) To conduct studies to determine
the health effects of exposure.
(iii) The request explains in detail
why the disclosure of the specific
chemical identity is essential and that,
in lieu thereof, the disclosure of the
following information would not enable
the health professional, employee or
designated representative to provide
the occupational health services described in paragraph (f)(4)(ii) of this
section:
(A) The properties and effects of the
chemical;
(B) Measures for controlling workers’
exposure to the chemical;
§ 1910.1020
(C) Methods of monitoring and analyzing worker exposure to the chemical; and,
(D) Methods of diagnosing and treating harmful exposures to the chemical;
(iv) The request includes a description of the procedures to be used to
maintain the confidentiality of the disclosed information; and,
(v) The health professional, employee, or designated representative
and the employer or contractor of the
services of the health professional or
designated representative agree in a
written confidentiality agreement that
the health professional, employee or
designated representative will not use
the trade secret information for any
purpose other than the health need(s)
asserted and agree not to release the
information under any circumstances
other than to OSHA, as provided in
paragraph (f)(9) of this section, except
as authorized by the terms of the
agreement or by the employer.
(5) The confidentiality agreement authorized by paragraph (f)(4)(iv) of this
section:
(i) May restrict the use of the information to the health purposes indicated in the written statement of need;
(ii) May provide for appropriate legal
remedies in the event of a breach of the
agreement, including stipulation of a
reasonable pre-estimate of likely damages; and,
(iii) May not include requirements
for the posting of a penalty bond.
(6) Nothing in this section is meant
to preclude the parties from pursuing
non-contractual remedies to the extent
permitted by law.
(7) If the health professional, employee or designated representative receiving the trade secret information
decides that there is a need to disclose
it to OSHA, the employer who provided
the information shall be informed by
the health professional prior to, or at
the same time as, such disclosure.
(8) If the employer denies a written
request for disclosure of a specific
chemical identity, the denial must:
(i) Be provided to the health professional, employee or designated representative within thirty days of the
request;
(ii) Be in writing;
101
§ 1910.1020
(iii) Include evidence to support the
claim that the specific chemical identity is a trade secret;
(iv) State the specific reasons why
the request is being denied; and,
(v) Explain in detail how alternative
information may satisfy the specific
medical or occupational health need
without revealing the specific chemical
identity.
(9) The health professional, employee, or designated representative
whose request for information is denied
under paragraph (f)(4) of this section
may refer the request and the written
denial of the request to OSHA for consideration.
(10) When a heath professional employee, or designated representative refers a denial to OSHA under paragraph
(f)(9) of this section, OSHA shall consider the evidence to determine if:
(i) The employer has supported the
claim that the specific chemical identity is a trade secret;
(ii) The health professional employee, or designated representative
has supported the claim that there is a
medical or occupational health need
for the information; and
(iii) The health professional, employee or designated representative has
demonstrated adequate means to protect the confidentiality.
(11)(i) If OSHA determines that the
specific chemical identity requested
under paragraph (f)(4) of this section is
not a bona fide trade secret, or that it
is a trade secret but the requesting
health professional, employee or designated representatives has a legitimate medical or occupational health
need for the information, has executed
a written confidentiality agreement,
and has shown adequate means for
complying with the terms of such
agreement, the employer will be subject to citation by OSHA.
(ii) If an employer demonstrates to
OSHA that the execution of a confidentiality agreement would not provide
sufficient protection against the potential harm from the unauthorized disclosure of a trade secret specific chemical identity, the Assistant Secretary
may issue such orders or impose such
additional limitations or conditions
upon the disclosure of the requested
chemical information as may be appro-
priate to assure that the occupational
health needs are met without an undue
risk of harm to the employer.
(12) Notwithstanding the existence of
a trade secret claim, an employer shall,
upon request, disclose to the Assistant
Secretary any information which this
section requires the employer to make
available. Where there is a trade secret
claim, such claim shall be made no
later than at the time the information
is provided to the Assistant Secretary
so that suitable determinations of
trade secret status can be made and
the necessary protections can be implemented.
(13) Nothing in this paragraph shall
be construed as requiring the disclosure under any circumstances of process or percentage of mixture information which is trade secret.
(g) Employee information. (1) Upon an
employee’s first entering into employment, and at least annually thereafter,
each employer shall inform current
employees covered by this section of
the following:
(i) The existence, location, and availability of any records covered by this
section;
(ii) The person responsible for maintaining and providing access to
records; and
(iii) Each employee’s rights of access
to these records.
(2) Each employer shall keep a copy
of this section and its appendices, and
make copies readily available, upon request, to employees. The employer
shall also distribute to current employees any informational materials concerning this section which are made
available to the employer by the Assistant Secretary of Labor for Occupational Safety and Health.
(h) Transfer of records. (1) Whenever
an employer is ceasing to do business,
the employer shall transfer all records
subject to this section to the successor
employer. The successor employer
shall receive and maintain these
records.
(2) Whenever an employer is ceasing
to do business and there is no successor
employer to receive and maintain the
records subject to this standard, the
employer shall notify affected current
employees of their rights of access to
records at least three (3) months prior
102
to the cessation of the employer’s business.
(3) Whenever an employer either is
ceasing to do business and there is no
successor employer to receive and
maintain the records, or intends to dispose of any records required to be preserved for at least thirty (30) years, the
employer shall:
(i) Transfer the records to the Director of the National Institute for Occupational Safety and Health (NIOSH) if
so required by a specific occupational
safety and health standard; or
(ii) Notify the Director of NIOSH in
writing of the impending disposal of
records at least three (3) months prior
to the disposal of the records.
(4) Where an employer regularly disposes of records required to be preserved for at least thirty (30) years, the
employer may, with at least (3) months
notice, notify the Director of NIOSH on
an annual basis of the records intended
to be disposed of in the coming year.
(i) Appendices. The information contained in appendices A and B to this
section is not intended, by itself, to
create any additional obligations not
otherwise imposed by this section nor
detract from any existing obligation.
APPENDIX A TO § 1910.20—SAMPLE AUTHORIZATION LETTER FOR THE RELEASE
OF
EMPLOYEE
MEDICAL
RECORD INFORMATION TO A DES(NONIGNATED
REPRESENTATIVE
MANDATORY)
I, ————— (full name of worker/patient),
hereby authorize —————— (individual or
organization holding the medical records) to
release to —————— (individual or organization authorized to receive the medical information), the following medical information from my personal medical records:
llllllllllllllllllllllll
(Describe generally the information desired
to be released)
I give my permission for this medical information to be used for the following purpose:
but I do not give permission for any other
use or re-disclosure of this information.
NOTE: Several extra lines are provided
below so that you can place additional restrictions on this authorization letter if you
want to. You may, however, leave these lines
blank. On the other hand, you may want to
(1) specify a particular expiration date for
§ 1910.1020
this letter (if less than one year); (2) describe
medical information to be created in the future that you intend to be covered by this
authorization letter; or (3) describe portions
of the medical information in your records
which you do not intend to be released as a
result of this letter.)
Full name of Employee or Legal Representative
Signature of Employee or Legal Representative
Date of Signature
APPENDIX B TO § 1910.20—AVAILABILITY
OF NIOSH REGISTRY OF TOXIC EFFECTS OF CHEMICAL SUBSTANCES
(RTECS) (NON-MANDATORY)
The final regulation, 29 CFR 1910.20, applies to all employee exposure and medical
records, and analyses thereof, of employees
exposed to toxic substances or harmful physical agents (paragraph (b)(2)). The term toxic
substance or harmful physical agent is defined
by paragraph (c)(13) to encompass chemical
substances, biological agents, and physical
stresses for which there is evidence of harmful health effects. The regulation uses the
latest printed edition of the National Institute for Occupational Safety and Health
(NIOSH) Registry of Toxic Effects of Chemical Substances (RTECS) as one of the chief
sources of information as to whether evidence of harmful health effects exists. If a
substance is listed in the latest printed
RTECS, the regulation applies to exposure
and medical records (and analyses of these
records) relevant to employees exposed to
the substance.
It is appropriate to note that the final regulation does not require that employers purchase a copy of RTECS, and many employers
need not consult RTECS to ascertain whether their employee exposure or medical
records are subject to the rule. Employers
who do not currently have the latest printed
edition of the NIOSH RTECS, however, may
desire to obtain a copy. The RTECS is issued
in an annual printed edition as mandated by
section 20(a)(6) of the Occupational Safety
and Health Act (29 U.S.C. 669(a)(6)).
The Introduction to the 1980 printed edition describes the RTECS as follows:
‘‘The 1980 edition of the Registry of Toxic
Effects of Chemical Substances, formerly
known as the Toxic Substances list, is the
ninth revision prepared in compliance with
the requirements of Section 20(a)(6) of the
103
§ 1910.1025
Occupational Safety and Health Act of 1970
(Public Law 91–596). The original list was
completed on June 28, 1971, and has been updated annually in book format. Beginning in
October 1977, quarterly revisions have been
provided in microfiche. This edition of the
Registry contains 168,096 listings of chemical
substances: 45,156 are names of different
chemicals with their associated toxicity
data and 122,940 are synonyms. This edition
includes approximately 5,900 new chemical
compounds that did not appear in the 1979
Registry. (p. xi)
‘‘The Registry’s purposes are many, and it
serves a variety of users. It is a single source
document for basic toxicity information and
for other data, such as chemical identifiers
ad information necessary for the preparation
of safety directives and hazard evaluations
for chemical substances. The various types
of toxic effects linked to literature citations
provide researchers and occupational health
scientists with an introduction to the toxicological literature, making their own review of the toxic hazards of a given substance easier. By presenting data on the lowest reported doses that produce effects by
several routes of entry in various species,
the Registry furnishes valuable information
to those responsible for preparing safety
data sheets for chemical substances in the
workplace. Chemical and production engineers can use the Registry to identify the
hazards which may be associated with chemical intermediates in the development of
final products, and thus can more readily select substitutes or alternative processes
which may be less hazardous. Some organizations, including health agencies and chemical companies, have included the NIOSH
Registry accession numbers with the listing
of chemicals in their files to reference toxicity information associated with those
chemicals. By including foreign language
chemical names, a start has been made toward providing rapid identification of substances produced in other countries. (p. xi)
‘‘In this edition of the Registry, the editors
intend to identify ‘‘all known toxic substances’’ which may exist in the environment and to provide pertinent data on the
toxic effects from known doses entering an
organism by any route described. (p xi)
‘‘It must be reemphasized that the entry of
a substance in the Registry does not automatically mean that it must be avoided. A
listing does mean, however, that the substance has the documented potential of being
harmful if misused, and care must be exercised to prevent tragic consequences. Thus,
the Registry lists many substances that are
common in everyday life and are in nearly
every household in the United States. One
can name a variety of such dangerous substances: prescription and non-prescription
drugs; food additives; pesticide concentrates,
sprays, and dusts; fungicides; herbicides;
paints; glazes, dyes; bleaches and other
household cleaning agents; alkalies; and various solvents and diluents. The list is extensive because chemicals have become an integral part of our existence.’’
The RTECS printed edition may be purchased from the Superintendent of Documents, U.S. Government Printing Office
(GPO), Washington, DC 20402 (202–783–3238).
Some employers may desire to subscribe to
the quarterly update to the RTECS which is
published in a microfiche edition. An annual
subscription to the quarterly microfiche may
be purchased from the GPO (Order the
‘‘Microfiche Edition, Registry of Toxic Effects of Chemical Substances’’). Both the
printed edition and the microfiche edition of
RTECS are available for review at many university and public libraries throughout the
country. The latest RTECS editions may
also be examined at the OSHA Technical
Data Center, Room N2439—Rear, United
States Department of Labor, 200 Constitution Avenue, NW., Washington, DC 20210 (202–
523–9700), or at any OSHA Regional or Area
Office (See, major city telephone directories
under United States Government-Labor Department).
[53 FR 38163, Sept. 29, 1988; 53 FR 49981, Dec.
13, 1988, as amended at 54 FR 24333, June 7,
1989; 55 FR 26431, June 28, 1990; 61 FR 9235,
Mar. 7, 1996. Redesignated at 61 FR 31430,
June 20, 1996]
§ 1910.1025
Lead.
(a) Scope and application. (1) This section applies to all occupational exposure to lead, except as provided in
paragraph (a)(2).
(2) This section does not apply to the
construction industry or to agricultural operations covered by 29 CFR
Part 1928.
(b) Definitions. Action level means employee exposure, without regard to the
use of respirators, to an airborne concentration of lead of 30 micrograms per
cubic meter of air (30 µg/m3) averaged
over an 8-hour period.
Health (NIOSH), U.S. Department of
Health, Education, and Welfare, or designee.
Lead means metallic lead, all inorganic lead compounds, and organic lead
soaps. Excluded from this definition
are all other organic lead compounds.
104
(c) Permissible exposure limit (PEL). (1)
The employer shall assure that no employee is exposed to lead at concentrations greater than fifty micrograms per
cubic meter of air (50 µg/m3) averaged
over an 8-hour period.
(2) If an employee is exposed to lead
for more than 8 hours in any work day,
the permissible exposure limit, as a
time weighted average (TWA) for that
day, shall be reduced according to the
following formula:
Maximum permissible limit (in µg/
m3)=400÷hours worked in the day.
(3) When respirators are used to supplement engineering and work practice
controls to comply with the PEL and
all the requirements of paragraph (f)
have been met, employee exposure, for
the purpose of determining whether the
employer has complied with the PEL,
may be considered to be at the level
provided by the protection factor of the
respirator for those periods the respirator is worn. Those periods may be
averaged with exposure levels during
periods when respirators are not worn
to determine the employee’s daily
TWA exposure.
(i) For the purposes of paragraph (d),
employee exposure is that exposure
which would occur if the employee
were not using a respirator.
(ii) With the exception of monitoring
under paragraph (d)(3), the employer
shall collect full shift (for at least 7
continuous hours) personal samples including at least one sample for each
shift for each job classification in each
work area.
(iii) Full shift personal samples shall
be representative of the monitored employee’s regular, daily exposure to
lead.
(2) Initial determination. Each employer who has a workplace or work
operation covered by this standard
shall determine if any exployee may be
exposed to lead at or above the action
level.
(3) Basis of initial determination. (i)
The employer shall monitor employee
exposures and shall base initial determinations on the employee exposure
monitoring results and any of the following, relevant considerations:
§ 1910.1025
(A) Any information, observations, or
calculations which would indicate employee exposure to lead;
(B) Any previous measurements of
airborne lead; and
(C) Any employee complaints of
symptoms which may be attributable
to exposure to lead.
(ii) Monitoring for the initial determination may be limited to a representative sample of the exposed employees who the employer reasonably
believes are exposed to the greatest
airborne concentrations of lead in the
workplace.
(iii) Measurements of airborne lead
made in the preceding 12 months may
be used to satisfy the requirement to
monitor under paragraph (d)(3)(i) if the
sampling and analytical methods used
meet the accuracy and confidence levels of paragraph (d)(9) of this section.
(4) Positive initial determination and
initial monitoring. (i) Where a determination conducted under paragraphs
(d) (2) and (3) of this section shows the
possibility of any employee exposure at
or above the action level, the employer
shall conduct monitoring which is representative of the exposure for each
employee in the workplace who is exposed to lead.
(ii) Measurements of airborne lead
made in the preceding 12 months may
be used to satisfy this requirement if
the sampling and analytical methods
used meet the accuracy and confidence
levels of paragraph (d)(9) of this section.
(5) Negative initial determination.
Where a determination, conducted
under paragraphs (d) (2) and (3) of this
section is made that no employee is exposed to airborne concentrations of
lead at or above the action level, the
employer shall make a written record
of such determination. The record shall
include at least the information specified in paragraph (d)(3) of this section
and shall also include the date of determination, location within the worksite, and the name and social security
number of each employee monitored.
(6) Frequency. (i) If the initial monitoring reveals employee exposure to be
below the action level the measurements need not be repeated except as
otherwise provided in paragraph (d)(7)
of this section.
105
§ 1910.1025
(ii) If the initial determination or
subsequent monitoring reveals employee exposure to be at or above the
action level but below the permissible
exposure limit the employer shall repeat monitoring in accordance with
this paragraph at least every 6 months.
The employer shall continue monitoring at the required frequency until
at least two consecutive measurements, taken at least 7 days apart, are
below the action level at which time
the employer may discontinue monitoring for that employee except as otherwise provided in paragraph (d)(7) of
this section.
(iii) If the initial monitoring reveals
that employee exposure is above the
permissible exposure limit the employer shall repeat monitoring quarterly. The employer shall continue
monitoring at the required frequency
until at least two consecutive measurements, taken at least 7 days apart, are
below the PEL but at or above the action level at which time the employer
shall repeat monitoring for that employee at the frequency specified in
paragraph (d)(6)(ii), except as otherwise
provided in paragraph (d)(7) of this section.
(7) Additional monitoring. Whenever
there has been a production, process,
control or personnel change which may
result in new or additional exposure to
lead, or whenever the employer has any
other reason to suspect a change which
may result in new or additional exposures to lead, additional monitoring in
accordance with this paragraph shall
be conducted.
(8) Employee notification. (i) Within 5
working days after the receipt of monitoring results, the employer shall notify each employee in writing of the results which represent that employee’s
exposure.
(ii) Whenever the results indicate
that the representative employee exposure, without regard to respirators, exceeds the permissible exposure limit,
the employer shall incude in the written notice a statement that the permissible exposure limit was exceeded
and a description of the corrective action taken or to be taken to reduce exposure to or below the permissible exposure limit.
(9) Accuracy of measurement. The employer shall use a method of monitoring and analysis which has an accuracy (to a confidence level of 95%) of
not less than plus or minus 20 percent
for airborne concentrations of lead
equal to or greater than 30 µg/m3.
(e) Methods of compliance—(1) Engineering and work practice controls. (i)
Where any employee is exposed to lead
above the permissible exposure limit
for more than 30 days per year, the employer shall implement engineering
and work practice controls (including
administrative controls) to reduce and
maintain employee exposure to lead in
accordance with the implementation
schedule in Table I below, except to the
extent that the employer can demonstrate that such controls are not feasible. Wherever the engineering and
work practice controls which can be instituted are not sufficient to reduce
employee exposure to or below the permissible exposure limit, the employer
shall nonetheless use them to reduce
exposures to the lowest feasible level
and shall supplement them by the use
of respiratory protection which complies with the requirements of paragraph (f) of this section.
(ii) Where any employee is exposed to
lead above the permissible exposure
limit, but for 30 days or less per year,
the employer shall implement engineering controls to reduce exposures to
200 µg/m3, but thereafter may implement any combination of engineering,
work practice (including administrative controls), and respiratory controls
to reduce and maintain employee exposure to lead to or below 50 µg/m3.
TABLE I
Industry
Lead chemicals, secondary copper
smelting.
Nonferrous foundries ...............................
Brass and bronze ingot manufacture ......
Compliance
dates: 1
(50 µg/m3)
July 19, 1996.
July 19, 1996. 2
6 years.3
1 Calculated by counting from the date the stay on implementation of paragraph (e)(1) was lifted by the U.S. Court of
Appeals for the District of Columbia, the number of years
specified in the 1978 lead standard and subsequent amendments for compliance with the PEL of 50 µ g/m3 for exposure
to airborne concentrations of lead levels for the particular industry.
2 Large nonferrous foundries (20 or more employees) are
required to achieve the PEL of 50 µ g/m3 by means of engineering and work practice controls. Small nonferrous foundries (fewer than 20 employees) are required to achieve an 8hour TWA of 75 µ g/m3 by such controls.
106
3 Expressed as the number of years from the date on which
the Court lifts the stay on the implementation of paragraph
(e)(1) for this industry for employers to achieve a lead in air
concentration of 75 µ g/m3. Compliance with paragraph (e) in
this industry is determined by a compliance directive that incorporates elements from the settlement agreement between
OSHA and representatives of the industry.
(2) Respiratory protection. Where engineering and work practice controls do
not reduce employee exposure to or
below the 50 µg/m3permissible exposure
limit, the employer shall supplement
these controls with respirators in accordance with paragraph (f).
(3) Compliance program. (i) Each employer shall establish and implement a
written compliance program to reduce
exposure limit, and interim levels if
applicable, solely by means of engineering and work practice controls in
accordance with the implementation
schedule in paragraph (e)(1).
(ii) Written plans for these compliance programs shall include at least
the following:
which lead is emitted; e.g. machinery
used, material processed, controls in
place, crew size, employee job responsibilities, operating procedures and
maintenance practices;
(B) A description of the specific
means that will be employed to achieve
compliance,
including
engineering
plans and studies used to determine
methods selected for controlling exposure to lead;
(C) A report of the technology considered in meeting the permissible exposure limit;
(D) Air monitoring data which documents the source of lead emissions;
(E) A detailed schedule for implementation of the program, including documentation such as copies of purchase
orders for equipment, construction
contracts, etc.;
(F) A work practice program which
includes items required under paragraphs (g), (h) and (i) of this regulation;
(G) An administrative control schedule required by paragraph (e)(6), if applicable;
(H) Other relevant information.
(iii) Written programs shall be submitted upon request to the Assistant
Secretary and the Director, and shall
be available at the worksite for examination and copying by the Assistant
§ 1910.1025
Secretary, Director, any affected employee or authorized employee representatives.
(iv) Written programs shall be revised and updated at least every 6
months to reflect the current status of
the program.
(4) Mechanical ventilation. (i) When
ventilation is used to control exposure,
measurements which demonstrate the
effectiveness of the system in controlling exposure, such as capture velocity,
duct velocity, or static pressure shall
be made at least every 3 months. Measurements of the system’s effectiveness
in controlling exposure shall be made
within 5 days of any change in production, process, or control which might
result in a change in employee exposure to lead.
(ii) Recirculation of air. If air from exhaust ventilation is recirculated into
the workplace, the employer shall assure that (A) the system has a high efficiency filter with reliable back-up filter; and (B) controls to monitor the
concentration of lead in the return air
and to bypass the recirculation system
automatically if it fails are installed,
operating, and maintained.
(5) Administrative controls. If administrative controls are used as a means of
reducing employees TWA exposure to
lead, the employer shall establish and
implement a job rotation schedule
which includes:
(i) Name or identification number of
each affected employee;
(ii) Duration and exposure levels at
each job or work station where each affected employee is located; and
(iii) Any other information which
may be useful in assessing the reliability of administrative controls to
reduce exposure to lead.
(f) Respiratory protection—(1) General.
(i) Periods necessary to install or implement engineering or work-practice
controls.
(ii) Work operations for which engineering and work-practice controls are
107
§ 1910.1025
not sufficient to reduce employee exposures to or below the permissible exposure limit.
(iii) Periods when an employee requests a respirator.
(ii) If an employee has breathing difficulty during fit testing or respirator
use, the employer must provide the employee with a medical examination in
accordance with paragraph (j)(3)(i)(C)
of this section to determine whether or
not the employee can use a respirator
while performing the required duty.
TABLE II—RESPIRATORY PROTECTION FOR LEAD AEROSOLS
Airborne concentration of lead or condition
of use
Required respirator
Not in excess of 0.5 mg/m3 (10X PEL) ......
Not in excess of 2.5 mg/m3 (50X PEL) ......
Not in excess of 50 mg/m3 (1000X PEL) ...
Half-mask, air-purifying respirator equipped with high efficiency filters.2 3
Full facepiece, air-purifying respirator with high efficiency filters.3
(1) Any powered, air-purifying respirator with high efficiency filters3; or (2) Halfmask supplied-air respirator operated in positive-pressure mode.2
Supplied-air respirators with full facepiece, hood, helmet, or suit, operated in positive pressure mode.
Full facepiece, self-contained breathing apparatus operated in positive-pressure
mode.
Not in excess of 100 mg/m3 (2000XPEL) ..
Greater than 100 mg/m3, unknown concentration or fire fighting.
1 Respirators
specified for high concentrations can be used at lower concentrations of lead.
facepiece is required if the lead aerosols cause eye or skin irritation at the use concentrations.
high efficiency particulate filter means 99.97 percent efficient against 0.3 micron size particles.
2 Full
3A
(3) Respirator selection. (i) The employer must select the appropriate respirator or combination of respirators
from Table II of this section.
(ii) The employer must provide a
powered air-purifying respirator instead of the respirator specified in
Table II of this section when an employee chooses to use this type of respirator and such a respirator provides
adequate protection to the employee.
(g) Protective work clothing and equipment—(1) Provision and use. If an employee is exposed to lead above the
PEL, without regard to the use of respirators or where the possibility of
skin or eye irritation exists, the employer shall provide at no cost to the
employee and assure that the employee
uses appropriate protective work clothing and equipment such as, but not
limited to:
work clothing;
(ii) Gloves, hats, and shoes or disposable shoe coverlets; and
other appropriate protective equipment which complies with § 1910.133 of
this Part.
employer shall provide the protective
clothing required in paragraph (g)(1) of
this section in a clean and dry condi-
tion at least weekly, and daily to employees whose exposure levels without
regard to a respirator are over 200 µg/
m3of lead as an 8-hour TWA.
(ii) The employer shall provide for
the cleaning, laundering, or disposal of
protective clothing and equipment required by paragraph (g)(1) of this section.
(iii) The employer shall repair or replace required protective clothing and
equipment as needed to maintain their
effectiveness.
all protective clothing is removed at
the completion of a work shift only in
change rooms provided for that purpose
as prescribed in paragraph (i)(2) of this
section.
contaminated
protective
clothing
which is to be cleaned, laundered, or
disposed of, is placed in a closed container in the change-room which prevents dispersion of lead outside the
container.
(vi) The employer shall inform in
writing any person who cleans or launders protective clothing or equipment
of the potentially harmful effects of exposure to lead.
(vii) The employer shall assure that
the containers of contaminated protective clothing and equipment required
108
by paragraph (g)(2)(v) are labelled as
follows:
CAUTION: CLOTHING CONTAMINATED
WITH LEAD. DO NOT REMOVE DUST BY
BLOWING OR SHAKING. DISPOSE OF
LEAD CONTAMINATED WASH WATER IN
ACCORDANCE WITH APPLICABLE LOCAL,
STATE, OR FEDERAL REGULATIONS.
(viii) The employer shall prohibit the
removal of lead from protective clothing or equipment by blowing, shaking,
or any other means which disperses
lead into the air.
(h) Housekeeping—(1) Surfaces. All
surfaces shall be maintained as free as
practicable of accumulations of lead.
(2) Cleaning floors. (i) Floors and
other surfaces where lead accumulates
may not be cleaned by the use of compressed air.
(ii) Shoveling, dry or wet sweeping,
and brushing may be used only where
vacuuming or other equally effective
methods have been tried and found not
to be effective.
(3) Vacuuming. Where vacuuming
methods are selected, the vacuums
shall be used and emptied in a manner
which minimizes the reentry of lead
into the workplace.
(i) Hygiene facilities and practices. (1)
The employer shall assure that in areas
where employees are exposed to lead
above the PEL, without regard to the
use of respirators, food or beverage is
not present or consumed, tobacco products are not present or used, and cosmetics are not applied, except in
change rooms, lunchrooms, and showers required under paragraphs (i)(2)
through (i)(4) of this section.
(2) Change rooms. (i) The employer
shall provide clean change rooms for
their airborne exposure to lead is above
the PEL, without regard to the use of
respirators.
change rooms are equipped with separate storage facilities for protective
work clothing and equipment and for
street clothes which prevent cross-contamination.
(3) Showers. (i) The employer shall assure that employees who work in areas
where their airborne exposure to lead
is above the PEL, without regard to
the use of respirators, shower at the
end of the work shift.
§ 1910.1025
(ii) The employer shall provide shower facilities in accordance with
§ 1910.141 (d)(3) of this part.
(iii) The employer shall assure that
employees who are required to shower
pursuant to paragraph (i)(3)(i) do not
leave the workplace wearing any clothing or equipment worn during the work
shift.
shall provide lunchroom facilities for
the PEL, without regard to the use of
respirators.
lunchroom facilities have a temperature controlled, positive pressure, filtered air supply, and are readily accessible to employees.
the PEL without regard to the use of a
respirator wash their hands and face
prior to eating, drinking, smoking or
applying cosmetics.
or equipment unless surface lead dust
has been removed by vacuuming,
downdraft booth, or other cleaning
method.
(5) Lavatories. The employer shall
provide an adequate number of lavatory facilities which comply with
§ 1910.141(d) (1) and (2) of this part.
(j) Medical surveillance—(1) General. (i)
The employer shall institute a medical
surveillance program for all employees
who are or may be exposed above the
action level for more than 30 days per
year.
all medical examinations and procedures are performed by or under the supervision of a licensed physician.
(iii) The employer shall provide the
required medical surveillance including
multiple physician review under paragraph (j)(3)(iii) without cost to employees and at a reasonable time and place.
(2) Biological monitoring—(i) Blood lead
and ZPP level sampling and analysis.
The employer shall make available biological monitoring in the form of blood
sampling and analysis for lead and zinc
protoporphyrin levels to each employee
109
§ 1910.1025
covered under paragraph (j)(1)(i) of this
section on the following schedule:
(A) At least every 6 months to each
employee covered under paragraph
(j)(1)(i) of this section;
(B) At least every two months for
each employee whose last blood sampling and analysis indicated a blood
lead level at or above 40 µ g/100 g of
whole blood. This frequency shall continue until two consecutive blood samples and analyses indicate a blood lead
level below 40 µ g/100 g of whole blood;
and
(C) At least monthly during the removal period of each employee removed from exposure to lead due to an
elevated blood lead level.
(ii) Follow-up blood sampling tests.
Whenever the results of a blood lead
level test indicate that an employee’s
blood lead level exceeds the numerical
criterion for medical removal under
paragraph (k)(1)(i)(A) of this section,
the employer shall provide a second
(follow-up) blood sampling test within
two weeks after the employer receives
the results of the first blood sampling
test.
(iii) Accuracy of blood lead level sampling and analysis. Blood lead level
sampling and analysis provided pursuant to this section shall have an accuracy (to a confidence level of 95 percent) within plus or minus 15 percent
or 6 µ g/100ml, whichever is greater, and
shall be conducted by a laboratory licensed by the Center for Disease Control, United States Department of
Health, Education and Welfare (CDC)
or which has received a satisfactory
grade in blood lead proficiency testing
from CDC in the prior twelve months.
(iv) Employee notification. Within five
working days after the receipt of biological monitoring results, the employer shall notify in writing each employee whose blood lead level exceeds
40 µ g/100 g: (A) of that employee’s
blood lead level and (B) that the standard requires temporary medical removal with Medical Removal Protection benefits when an employee’s blood
lead level exceeds the numerical criterion for medical removal under paragraph (k)(1)(i) of this section.
(3) Medical examinations and consultations—(i) Frequency. The employer shall
make available medical examinations
and consultations to each employee
covered under paragraph (j)(1)(i) of this
section on the following schedule:
(A) At least annually for each employee for whom a blood sampling test
conducted at any time during the preceding 12 months indicated a blood lead
level at or above 40 µ g/100 g;
(B) Prior to assignment for each employee being assigned for the first time
to an area in which airborne concentrations of lead are at or above the action
level;
(C) As soon as possible, upon notification by an employee either that the
employee has developed signs or symptoms commonly associated with lead
intoxication, that the employee desires
medical advice concerning the effects
of current or past exposure to lead on
the employee’s ability to procreate a
healthy child, or that the employee has
demonstrated difficulty in breathing
during a respirator fitting test or during use; and
(D) As medically appropriate for each
employee either removed from exposure to lead due to a risk of sustaining
material impairment to health, or otherwise limited pursuant to a final medical determination.
(ii) Content. Medical examinations
made available pursuant to paragraph
(j)(3)(i) (A) through (B) of this section
shall include the following elements:
(A) A detailed work history and a
medical history, with particular attention to past lead exposure (occupational and non-occupational), personal
habits (smoking, hygiene), and past
gastrointestinal, hematologic, renal,
cardiovascular, reproductive and neurological problems;
(B) A thorough physical examination,
with particular attention to teeth,
gums, hematologic, gastrointestinal,
renal, cardiovascular, and neurological
systems. Pulmonary status should be
evaluated if respiratory protection will
be used;
(C) A blood pressure measurement;
(D) A blood sample and analysis
which determines:
(1) Blood lead level;
(2) Hemoglobin and hematocrit determinations, red cell indices, and examination of peripheral smear morphology;
(3) Zinc protoporphyrin;
110
(4) Blood urea nitrogen; and,
(5) Serum creatinine;
(E) A routine urinalysis with microscopic examination; and
(F) Any laboratory or other test
which the examining physician deems
necessary by sound medical practice.
The content of medical examinations
made available pursuant to paragraph
(j)(3)(i) (C) through (D) of this section
shall be determined by an examining
physician and, if requested by an employee, shall include pregnancy testing
or laboratory evaluation of male fertility.
(iii) Multiple physician review mechanism. (A) If the employer selects the
initial physician who conducts any
medical examination or consultation
provided to an employee under this section, the employee may designate a
second physician:
(1) To review any findings, determinations or recommendations of the
initial physician; and
(2) To conduct such examinations,
consultations, and laboratory tests as
the second physician deems necessary
to facilitate this review.
(B) The employer shall promptly notify an employee of the right to seek a
second medical opinion after each occasion that an initial physician conducts a medical examination or consultation pursuant to this section. The
employer may condition its participation in, and payment for, the multiple
physician review mechanism upon the
employee doing the following within
fifteen (15) days after receipt of the
foregoing notification, or receipt of the
initial physician’s written opinion,
whichever is later:
(1) The employee informing the employer that he or she intends to seek a
second medical opinion, and
(2) The employee initiating steps to
make an appointment with a second
physician.
(C) If the findings, determinations or
recommendations of the second physician differ from those of the initial
physician, then the employer and the
employee shall assure that efforts are
made for the two physicians to resolve
any disagreement.
(D) If the two physicians have been
unable to quickly resolve their disagreement, then the employer and the
§ 1910.1025
employee through their respective physicians shall designate a third physician:
(1) To review any findings, determinations or recommendations of the
prior physicians; and
(2) To conduct such examinations,
consultations, laboratory tests and discussions with the prior physicians as
the third physician deems necessary to
resolve the disagreement of the prior
physicians.
(E) The employer shall act consistent
with the findings, determinations and
recommendations of the third physician, unless the employer and the employee reach an agreement which is
otherwise consistent with the recommendations of at least one of the
three physicians.
(iv) Information provided to examining
and consulting physicians. (A) The employer shall provide an initial physician conducting a medical examination
or consultation under this section with
(1) A copy of this regulation for lead
including all Appendices;
(2) A description of the affected employee’s duties as they relate to the
(3) The employee’s exposure level or
anticipated exposure level to lead and
to any other toxic substance (if applicable);
(4) A description of any personal protective equipment used or to be used;
(5) Prior blood lead determinations;
and
(6) All prior written medical opinions
concerning the employee in the employer’s possession or control.
(B) The employer shall provide the
foregoing information to a second or
third physician conducting a medical
examination or consultation under this
section upon request either by the second or third physician, or by the employee.
(v) Written medical opinions. (A) The
employer shall obtain and furnish the
employee with a copy of a written medical opinion from each examining or
consulting physician which contains
(1) The physician’s opinion as to
medical condition which would place
111
§ 1910.1025
the employee at increased risk of material impairment of the employee’s
health from exposure to lead;
(2) Any recommended special protective measures to be provided to the employee, or limitations to be placed
upon the employee’s exposure to lead;
(3) Any recommended limitation
upon the employee’s use of respirators,
including a determination of whether
the employee can wear a powered air
purifying respirator if a physician determines that the employee cannot
wear a negative pressure respirator;
and
(4) The results of the blood lead determinations.
(B) The employer shall instruct each
examining and consulting physician to:
(1) Not reveal either in the written
opinion, or in any other means of communication with the employer, findings, including laboratory results, or
diagnoses unrelated to an employee’s
occupational exposure to lead; and
(2) Advise the employee of any medical condition, occupational or nonoccupational, which dictates further
medical examination or treatment.
(vi) Alternate Physician Determination
Mechanisms. The employer and an employee or authorized employee representative may agree upon the use of
any expeditious alternate physician determination mechanism in lieu of the
multiple physician review mechanism
provided by this paragraph so long as
the alternate mechanism otherwise
satisfies the requirements contained in
this paragraph.
(4) Chelation. (i) The employer shall
assure that any person whom he retains, employs, supervises or controls
does not engage in prophylactic chelation of any employee at any time.
(ii) If therapeutic or diagnostic chelation is to be performed by any person
in paragraph (j)(4)(i), the employer
shall assure that it be done under the
supervision of a licensed physician in a
clinical setting with thorough and appropriate medical monitoring and that
the employee is notified in writing
prior to its occurrence.
(k) Medical Removal Protection—(1)
Temporary medical removal and return of
an employee—(i) Temporary removal due
to elevated blood lead levels. (A) The employer shall remove an employee from
work having an exposure to lead at or
above the action level on each occasion
that a periodic and a follow-up blood
sampling test conducted pursuant to
this section indicate that the employee’s blood lead level is at or above 60 µ
g/100 g of whole blood; and
(B) The employer shall remove an
employee from work having an exposure to lead at or above the action
level on each occasion that the average
of the last three blood sampling tests
conducted pursuant to this section (or
the average of all blood sampling tests
conducted over the previous six (6)
months, whichever is longer) indicates
that the employee’s blood lead level is
at or above 50 µ g/100 g of whole blood;
provided, however, that an employee
need not be removed if the last blood
sampling test indicates a blood lead
level at or below 40 µ g/100 g of whole
blood.
(ii) Temporary removal due to a final
medical determination. (A) The employer
shall remove an employee from work
having an exposure to lead at or above
the action level on each occasion that
a final medical determination results
in a medical finding, determination, or
opinion that the employee has a detected medical condition which places
the employee at increased risk of material impairment to health from exposure to lead.
(B) For the purposes of this section,
the phrase ‘‘final medical determination’’ shall mean the outcome of the
multiple physician review mechanism
or alternate medical determination
mechanism used pursuant to the medical surveillance provisions of this section.
(C) Where a final medical determination results in any recommended special protective measures for an employee, or limitations on an employee’s
exposure to lead, the employer shall
implement and act consistent with the
recommendation.
(iii) Return of the employee to former
job status. (A) The employer shall return an employee to his or her former
job status:
(1) For an employee removed due to a
blood lead level at or above 60 µg/100 g,
or due to an average blood lead level at
or above 50 µg/100 g, when two consecutive blood sampling tests indicate that
112
the employee’s blood lead level is at or
below 40 µg/100 g of whole blood;
(2) For an employee removed due to a
final medical determination, when a
subsequent final medical determination results in a medical finding, determination, or opinion that the employee
no longer has a detected medical condition which places the employee at increased risk of material impairment to
health from exposure to lead.
(B) For the purposes of this section,
the requirement that an employer return an employee to his or her former
job status is not intended to expand
upon or restrict any rights an employee has or would have had, absent
temporary medical removal, to a specific job classification or position
under the terms of a collective bargaining agreement.
(iv) Removal of other employee special
protective measure or limitations. The
employer shall remove any limitations
placed on an employee or end any special protective measures provided to an
employee pursuant to a final medical
determination when a subsequent final
medical determination indicates that
the limitations or special protective
measures are no longer necessary.
(v) Employer options pending a final
medical determination. Where the multiple physician review mechanism, or
alternate medical determination mechanism used pursuant to the medical
surveillance provisions of this section,
has not yet resulted in a final medical
determination with respect to an employee, the employer shall act as follows:
(A) Removal. The employer may remove the employee from exposure to
lead, provide special protective measures to the employee, or place limitations upon the employee, consistent
with the medical findings, determinations, or recommendations of any of
the physicians who have reviewed the
employee’s health status.
(B) Return. The employer may return
the employee to his or her former job
status, end any special protective
measures provided to the employee,
and remove any limitations placed
upon the employee, consistent with the
medical findings, determinations, or
recommendations of any of the physicians who have reviewed the employ-
§ 1910.1025
ee’s health status, with two exceptions.
If
(1) the initial removal, special protection, or limitation of the employee
resulted from a final medical determination which differed from the findings, determinations, or recommendations of the initial physician or
(2) The employee has been on removal status for the preceding eighteen months due to an elevated blood
lead level, then the employer shall
await a final medical determination.
(2) Medical removal protection benefits—(i) Provision of medical removal protection benefits. The employer shall provide to an employee up to eighteen (18)
months of medical removal protection
benefits on each occasion that an employee is removed from exposure to
lead or otherwise limited pursuant to
this section.
(ii) Definition of medical removal protection benefits. For the purposes of this
section, the requirement that an employer provide medical removal protection benefits means that the employer
shall maintain the earnings, seniority
and other employment rights and benefits of an employee as though the employee had not been removed from normal exposure to lead or otherwise limited.
(iii) Follow-up medical surveillance
during the period of employee removal or
limitation. During the period of time
that an employee is removed from normal exposure to lead or otherwise limited, the employer may condition the
provision of medical removal protection benefits upon the employee’s participation in follow-up medical surveillance made available pursuant to this
section.
(iv) Workers’ compensation claims. If a
removed employee files a claim for
workers’ compensation payments for a
lead-related disability, then the employer shall continue to provide medical removal protection benefits pending disposition of the claim. To the extent that an award is made to the employee for earnings lost during the period of removal, the employer’s medical removal protection obligation
shall be reduced by such amount. The
employer shall receive no credit for
113
§ 1910.1025
workers’ compensation payments received by the employee for treatment
related expenses.
(v) Other credits. The employer’s obligation to provide medical removal protection benefits to a removed employee
shall be reduced to the extent that the
employee receives compensation for
earnings lost during the period of removal either from a publicly or employer-funded compensation program,
or receives income from employment
with another employer made possible
by virtue of the employee’s removal.
(vi) Employees whose blood lead levels
do not adequately decline within 18
months of removal. The employer shall
take the following measures with respect to any employee removed from
exposure to lead due to an elevated
blood lead level whose blood lead level
has not declined within the past eighteen (18) months of removal so that the
employee has been returned to his or
her former job status:
(A) The employer shall make available to the employee a medical examination pursuant to this section to obtain a final medical determination
with respect to the employee;
(B) The employer shall assure that
the final medical determination obtained indicates whether or not the
employee may be returned to his or her
former job status, and if not, what
steps should be taken to protect the
employee’s health;
(C) Where the final medical determination has not yet been obtained, or
once obtained indicates that the employee may not yet be returned to his
or her former job status, the employer
shall continue to provide medical removal protection benefits to the employee until either the employee is returned to former job status, or a final
medical determination is made that
the employee is incapable of ever safely returning to his or her former job
status.
(D) Where the employer acts pursuant to a final medical determination
which permits the return of the employee to his or her former job status
despite what would otherwise be an unacceptable blood lead level, later questions concerning removing the employee again shall be decided by a final
medical determination. The employer
need not automatically remove such an
employee pursuant to the blood lead
level removal criteria provided by this
section.
(vii) Voluntary Removal or Restriction
of An Employee. Where an employer, although not required by this section to
do so, removes an employee from exposure to lead or otherwise places limitations on an employee due to the effects
of lead exposure on the employee’s
medical condition, the employer shall
provide medical removal protection
benefits to the employee equal to that
required by paragraph (k)(2)(i) of this
section.
(l) Employee information and training—
(1) Training program. (i) Each employer
who has a workplace in which there is
a potential exposure to airborne lead at
any level shall inform employees of the
content of Appendices A and B of this
regulation.
(ii) The employer shall institute a
training program for and assure the
participation of all employees who are
subject to exposure to lead at or above
the action level or for whom the possibility of skin or eye irritation exists.
(iii) The employer shall provide initial training by 180 days from the effective date for those employees covered
by paragraph (l)(1) (ii) on the standard’s effective date and prior to the
time of initial job assignment for those
employees subsequently covered by
this paragraph.
(iv) The training program shall be repeated at least annually for each employee.
each employee is informed of the following:
(A) The content of this standard and
its appendices;
(B) The specific nature of the operations which could result in exposure
to lead above the action level;
(C) The purpose, proper selection, fitting, use, and limitations of respirators;
(D) The purpose and a description of
the medical surveillance program, and
the medical removal protection program including information concerning
the adverse health effects associated
with excessive exposure to lead (with
114
particular attention to the adverse reproductive effects on both males and
females);
(E) The engineering controls and
(F) The contents of any compliance
plan in effect; and
(G) Instructions to employees that
chelating agents should not routinely
be used to remove lead from their bodies and should not be used at all except
under the direction of a licensed physician;
(2) Access to information and training
materials. (i) The employer shall make
readily available to all affected employees a copy of this standard and its
appendices.
(ii) The employer shall provide, upon
and the Director.
(iii) In addition to the information
required by paragraph (l)(1)(v), the employer shall include as part of the
training program, and shall distribute
to employees, any materials pertaining
to the Occupational Safety and Health
Act, the regulations issued pursuant to
that Act, and this lead standard, which
are made available to the employer by
the Assistant Secretary.
(m) Signs—(1) General. (i) The employer may use signs required by other
statutes, regulations or ordinances in
addition to, or in combination with,
signs required by this paragraph.
statement appears on or near any sign
required by this paragraph which contradicts or detracts from the meaning
of the required sign.
(2) Signs. (i) The employer shall post
the following warning signs in each
work area where the PEL is exceeded:
WARNING
LEAD WORK AREA
POISON
signs required by this paragraph are illuminated and cleaned as necessary so
that the legend is readily visible.
§ 1910.1025
(n) Recordkeeping—(1) Exposure monitoring. (i) The employer shall establish
and maintain an accurate record of all
monitoring required in paragraph (d) of
this section.
(A) The date(s), number, duration, location and results of each of the samples taken, including a description of
the sampling procedure used to determine representative employee exposure
where applicable;
of their accuracy;
(C) The type of respiratory protective
devices worn, if any;
(D) Name, social security number,
and job classification of the employee
monitored and of all other employees
whose exposure the measurement is intended to represent; and
(E) The environmental variables that
could affect the measurement of employee exposure.
these monitoring records for at least 40
years or for the duration of employment plus 20 years, whichever is
longer.
accurate record for each employee subject to medical surveillance as required
by paragraph (j) of this section.
(A) The name, social security number, and description of the duties of the
employee;
opinions;
(C) Results of any airborne exposure
monitoring done for that employee and
the representative exposure levels supplied to the physician; and
(D) Any employee medical complaints related to exposure to lead.
(iii) The employer shall keep, or assure that the examining physician
keeps, the following medical records:
(A) A copy of the medical examination results including medical and
work history required under paragraph
(j) of this section;
(B) A description of the laboratory
procedures and a copy of any standards
or guidelines used to interpret the test
results or references to that information;
115
§ 1910.1025
(C) A copy of the results of biological
monitoring.
(iv) The employer shall maintain or
assure that the physician maintains
those medical records for at least 40
years, or for the duration of employment plus 20 years, whichever is
longer.
(3) Medical removals. (i) The employer
shall establish and maintain an accurate record for each employee removed
from current exposure to lead pursuant
to paragraph (k) of this section.
(ii) Each record shall include:
(B) The date on each occasion that
the employee was removed from current exposure to lead as well as the
corresponding date on which the employee was returned to his or her
former job status;
(C) A brief explanation of how each
removal was or is being accomplished;
and
(D) A statement with respect to each
removal indicating whether or not the
reason for the removal was an elevated
blood lead level.
each medical removal record for at
least the duration of an employee’s employment.
make available upon request all
paragraph (n) of this section to the Assistant Secretary and the Director for
(ii) Environmental monitoring, medical removal, and medical records required by this paragraph shall be provided upon request to employees, designated representatives, and the Assistant Secretary in accordance with 29
CFR 1910.20 (a)–(e) and (2)–(i). Medical
removal records shall be provided in
the same manner as environmental
monitoring records.
(5) Transfer of records. (i) Whenever
the employer ceases to do business, the
successor employer shall receive and
retain all records required to be maintained by paragraph (n) of this section.
this section for the prescribed period,
these records shall be transmitted to
the Director.
(iii) At the expiration of the retention period for the records required to
be maintained by this section, the employer shall notify the Director at
least 3 months prior to the disposal of
such records and shall transmit those
records to the Director if requested
within the period.
(iv) The employer shall also comply
with any additional requirements involving transfer of records set forth in
29 CFR 1910.20(h).
(o) Observation of monitoring. (1) Employee observation. The employer shall
employee exposure to lead conducted
pursuant to paragraph (d) of this section.
(2) Observation procedures. (i) Whenever observation of the monitoring of
employee exposure to lead requires
entry into an area where the use of respirators, protective clothing or equipment is required, the employer shall
provide the observer with and assure
the use of such respirators, clothing
and such equipment, and shall require
the observer to comply with all other
applicable safety and health procedures.
(ii) Without interfering with the
monitoring, observers shall be entitled
to:
(A) Receive an explanation of the
measurement procedures;
(B) Observe all steps related to the
monitoring of lead performed at the
place of exposure; and
(C) Record the results obtained or receive copies of the results when returned by the laboratory.
(p) Effective date. This standard shall
become effective March 1, 1979.
(q) Appendices. The information contained in the appendices to this section
is not intended by itself, to create any
imposed by this standard nor detract
from any existing obligation.
(r) Startup dates. All obligations of
this standard commence on the effective date except as follows:
(1) The initial determination under
paragraph (d)(2) shall be made as soon
116
as possible but no later than 30 days
from the effective date.
(2) Initial monitoring under paragraph (d)(4) shall be completed as soon
as possible but no later than 90 days
(3) Initial biological monitoring and
medical examinations under paragraph
(j) shall be completed as soon as possible but no later than 180 days from
the effective date. Priority for biological monitoring and medical examinations shall be given to employees whom
the employer believes to be at greatest
risk from continued exposure.
(4) Initial training and education
shall be completed as soon as possible
but no later than 180 days from the effective date.
(5) Hygiene and lunchroom facilities
under paragraph (i) shall be in operation as soon as possible but no later
than 1 year from the effective year.
(6)(i) Respiratory protection required
by paragraph (f) shall be provided as
soon as possible but no later than the
following schedule:
(A) Employees whose 8-hour TWA exposure exceeds 200 µg/m3—on the effective date.
(B) Employees whose 8-hour TWA exposure exceeds the PEL but is less than
200 µg/m3—150 days from the effective
date.
(C) Powered, air-purifying respirators
provided under (f)(2)(ii)—210 days from
the effective date.
(D) Quantitative fit testing required
under (f)(3)(ii)—one year from effective
date. Qualitative fit testing is required
in the interim.
(7)(i) Written compliance plans required by paragraph (e)(3) shall be completed and available for inspection and
copying as soon as possible but no later
than the following schedule:
(A) Employers for whom compliance
with the PEL or interim level is required within 1 year from the effective
date—6 months from the effective date.
(B) Employers in secondary lead
smelting and refining and in lead storage battery manufacturing—1 year
(C) Employers in primary smelting
and refining industry—1 year from the
effective date for the interim level; 5
years from the effective date for PEL.
§ 1910.1025
(D) Plans for construction of hygiene
facilities, if required—6 months from
the effective date.
(E) All other industries—1 year from
the date on which the court lifts the
stay on the implementation of paragraph (e)(1) for the particular industry.
(8) The permissible exposure limit in
paragraph (c) shall become effective 150
days from the effective date.
APPENDIX A TO § 1910.1025—SUBSTANCE
DATA SHEET FOR OCCUPATIONAL EXPOSURE TO LEAD
I.
SUBSTANCE IDENTIFICATION
A. Substance: Pure lead (Pb) is a heavy
metal at room temperature and pressure and
is a basic chemical element. It can combine
with various other substances to form numerous lead compounds.
B. Compounds Covered by the Standard: The
word ‘‘lead’’ when used in this standard
means elemental lead, all inorganic lead
compounds and a class of organic lead compounds called lead soaps. This standard does
not apply to other organic lead compounds.
C. Uses: Exposure to lead occurs in at least
120 different occupations, including primary
and secondary lead smelting, lead storage
battery manufacturing, lead pigment manufacturing and use, solder manufacturing and
use, shipbuilding and ship repairing, auto
manufacturing, and printing.
D. Permissible Exposure: The Permissible
Exposure Limit (PEL) set by the standard is
50 micrograms of lead per cubic meter of air
(50 µg/m3), averaged over an 8-hour workday.
E. Action Level: The standard establishes
an action level of 30 micrograms per cubic
meter of air (30 µg/m3), time weighted average, based on an 8-hour work-day. The action
level initiates several requirements of the
standard, such as exposure monitoring, medical surveillance, and training and education.
A. Ways in which lead enters your body.
When absorbed into your body in certain
doses lead is a toxic substance. The object of
the lead standard is to prevent absorption of
harmful quantities of lead. The standard is
intended to protect you not only from the
immediate toxic effects of lead, but also
from the serious toxic effects that may not
become apparent until years of exposure
have passed.
Lead can be absorbed into your body by inhalation (breathing) and ingestion (eating).
Lead (except for certain organic lead compounds not covered by the standard, such as
tetraethyl lead) is not absorbed through
your skin. When lead is scattered in the air
as a dust, fume or mist it can be inhaled and
117
§ 1910.1025
absorbed through you lungs and upper respiratory tract. Inhalation of airborne lead is
generally the most important source of occupational lead absorption. You can also absorb lead through your digestive system if
lead gets into your mouth and is swallowed.
If you handle food, cigarettes, chewing tobacco, or make-up which have lead on them
or handle them with hands contaminated
with lead, this will contribute to ingestion.
A significant portion of the lead that you
inhale or ingest gets into your blood stream.
Once in your blood stream, lead is circulated
throughout your body and stored in various
organs and body tissues. Some of this lead is
quickly filtered out of your body and excreted, but some remains in the blood and
other tissues. As exposure to lead continues,
the amount stored in your body will increase
if you are absorbing more lead than your
body is excreting. Even though you may not
be aware of any immediate symptoms of disease, this lead stored in your tissues can be
slowly causing irreversible damage, first to
individual cells, then to your organs and
whole body systems.
B. Effects of overexposure to lead—(1) Short
term (acute) overexposure. Lead is a potent,
systemic poison that serves no known useful
function once absorbed by your body. Taken
in large enough doses, lead can kill you in a
matter of days. A condition affecting the
brain called acute encephalopathy may arise
which develops quickly to seizures, coma,
and death from cardiorespiratory arrest. A
short term dose of lead can lead to acute
encephalopathy. Short term occupational exposures of this magnitude are highly unusual, but not impossible. Similar forms of
encephalopathy may, however, arise from extended, chronic exposure to lower doses of
lead. There is no sharp dividing line between
rapidly developing acute effects of lead, and
chronic effects which take longer to acquire.
Lead adversely affects numerous body systems, and causes forms of health impairment
and disease which arise after periods of exposure as short as days or as long as several
years.
(2) Long-term (chronic) overexposure. Chronic overexposure to lead may result in severe
damage to your blood-forming, nervous, urinary and reproductive systems. Some common symptoms of chronic overexposure include loss of appetite, metallic taste in the
mouth, anxiety, constipation, nausea, pallor,
excessive tiredness, weakness, insomnia,
headache, nervous irritability, muscle and
joint pain or soreness, fine tremors, numbness, dizziness, hyperactivity and colic. In
lead colic there may be severe abdominal
pain.
Damage to the central nervous system in
general and the brain (encephalopathy) in
particular is one of the most severe forms of
lead poisoning. The most severe, often fatal,
form of encephalopathy may be preceded by
vomiting, a feeling of dullness progressing to
drowsiness and stupor, poor memory, restlessness, irritability, tremor, and convulsions. It may arise suddenly with the onset
of seizures, followed by coma, and death.
There is a tendency for muscular weakness
to develop at the same time. This weakness
may progress to paralysis often observed as
a characteristic ‘‘wrist drop’’ or ‘‘foot drop’’
and is a manifestation of a disease to the
nervous system called peripheral neuropathy.
Chronic overexposure to lead also results
in kidney disease with few, if any, symptoms
appearing until extensive and most likely
permanent kidney damage has occurred.
Routine laboratory tests reveal the presence
of this kidney disease only after about twothirds of kidney function is lost. When overt
symptoms of urinary dysfunction arise, it is
often too late to correct or prevent worsening conditions, and progression to kidney
dialysis or death is possible.
Chronic overexposure to lead impairs the
reproductive systems of both men and
women. Overexposure to lead may result in
decreased sex drive, impotence and sterility
in men. Lead can alter the structure of
sperm cells raising the risk of birth defects.
There is evidence of miscarriage and stillbirth in women whose husbands were exposed
to lead or who were exposed to lead themselves. Lead exposure also may result in decreased fertility, and abnormal menstrual
cycles in women. The course of pregnancy
may be adversely affected by exposure to
lead since lead crosses the placental barrier
and poses risks to developing fetuses. Children born of parents either one of whom were
exposed to excess lead levels are more likely
to have birth defects, mental retardation, behavioral disorders or die during the first
year of childhood.
Overexposure to lead also disrupts the
blood-forming system resulting in decreased
hemoglobin (the substance in the blood that
carries oxygen to the cells) and ultimately
anemia. Anemia is characterized by weakness, pallor and fatigability as a result of decreased oxygen carrying capacity in the
blood.
(3) Health protection goals of the standard.
Prevention of adverse health effects for most
workers from exposure to lead throughout a
working lifetime requires that worker blood
lead (PbB) levels be maintained at or below
forty micrograms per one hundred grams of
whole blood (40 µg/100g). The blood lead levels of workers (both male and female workers) who intend to have children should be
maintained below 30 µg/100g to minimize adverse reproductive health effects to the parents and to the developing fetus.
The measurement of your blood lead level
is the most useful indicator of the amount of
lead being absorbed by your body. Blood lead
levels (PbB) are most often reported in units
118
of milligrams (mg) or micrograms (µg) of
lead (1 mg=1000 µg) per 100 grams (100g), 100
milliters (100 ml) or deciliter (dl) of blood.
These three units are essentially the same.
Sometime PbB’s are expressed in the form of
mg% or µg%. This is a shorthand notation
for 100g, 100 ml, or dl.
PbB measurements show the amount of
lead circulating in your blood stream, but do
not give any information about the amount
of lead stored in your various tissues. PbB
measurements merely show current absorption of lead, not the effect that lead is having on your body or the effects that past lead
exposure may have already caused. Past research into lead-related diseases, however,
has focused heavily on associations between
PbBs and various diseases. As a result, your
PbB is an important indicator of the likelihood that you will gradually acquire a leadrelated health impairment or disease.
Once your blood lead level climbs above 40
µg/100g, your risk of disease increases. There
is a wide variability of individual response to
lead, thus it is difficult to say that a particular PbB in a given person will cause a
particular effect. Studies have associated
fatal encephalopathy with PbBs as low as 150
µg/100g. Other studies have shown other
forms of diseases in some workers with PbBs
well below 80 µg/100g. Your PbB is a crucial
indicator of the risks to your health, but one
other factor is also extremely important.
This factor is the length of time you have
had elevated PbBs. The longer you have an
elevated PbB, the greater the risk that large
quantities of lead are being gradually stored
in your organs and tissues (body burden).
The greater your overall body burden, the
greater the chances of substantial permanent damage.
The best way to prevent all forms of leadrelated impairments and diseases—both
short term and long term- is to maintain
your PbB below 40 µg/100g. The provisions of
the standard are designed with this end in
mind. Your employer has prime responsibility to assure that the provisions of the
standard are complied with both by the company and by individual workers. You as a
worker, however, also have a responsibility
to assist your employer in complying with
the standard. You can play a key role in protecting your own health by learning about
the lead hazards and their control, learning
what the standard requires, following the
standard where it governs your own actions,
and seeing that your employer complies with
provisions governing his actions.
(4) Reporting signs and symptoms of health
problems. You should immediately notify
your employer if you develop signs or symptoms associated with lead poisoning or if you
desire medical advice concerning the effects
of current or past exposure to lead on your
ability to have a healthy child. You should
also notify your employer if you have dif-
§ 1910.1025
ficulty breathing during a respirator fit test
or while wearing a respirator. In each of
these cases your employer must make available to you appropriate medical examinations or consultations. These must be provided at no cost to you and at a reasonable
time and place.
The standard contains a procedure whereby you can obtain a second opinion by a physician of your choice if the employer selected
the initial physician.
APPENDIX B TO § 1910.1025—EMPLOYEE
STANDARD SUMMARY
This appendix summarizes key provisions
of the standard that you as a worker should
become familiar with.
I.
PERMISSIBLE EXPOSURE LIMIT (PEL)—
PARAGRAPH (c)
The standards sets a permissible exposure
limit (PEL) of fifty micrograms of lead per
cubic meter of air (50 µg/m3), averaged over
an 8-hour work-day. This is the highest level
of lead in air to which you may be permissibly exposed over an 8-hour workday. Since
it is an 8-hour average it permits short exposures above the PEL so long as for each 8hour work day your average exposure does
not exceed the PEL.
This standard recognizes that your daily
exposure to lead can extend beyond a typical
8-hour workday as the result of overtime or
other alterations in your work schedule. To
deal with this, the standard contains a formula which reduces your permissible exposure when you are exposed more than 8
hours. For example, if you are exposed to
lead for 10 hours a day, the maximum permitted average exposure would be 40 µg/m3.
II. EXPOSURE MONITORING—PARAGRAPH
(d)
If lead is present in the workplace where
you work in any quantity, your employer is
required to make an initial determination of
whether the action level is exceeded for any
employee. This initial determination must
include instrument monitoring of the air for
the presence of lead and must cover the exposure of a representative number of employees who are reasonably believed to have
the highest exposure levels. If your employer
has conducted appropriate air sampling for
lead in the past year he may use these results. If there have been any employee complaints of symptoms which may be attributable to exposure to lead or if there is any
other information or observations which
would indicate employee exposure to lead,
this must also be considered as part of the
initial determination. This initial determination must have been completed by
March 31, 1979. If this initial determination
shows that a reasonable possibility exists
that any employee may be exposed, without
119
§ 1910.1025
regard to respirators, over the action level
(30 µg/m3) your employer must set up an air
monitoring program to determine the exposure level of every employee exposed to lead
at your workplace.
In carrying out this air monitoring program, your employer is not required to monitor the exposure of every employee, but he
must monitor a representative number of
employees and job types. Enough sampling
must be done to enable each employee’s exposure level to be reasonably least one full
shift (at least 7 hours) air sample. In addition, these air samples must be taken under
conditions which represent each employee’s
regular, daily exposure to lead. All initial exposure monitoring must have been completed by May 30, 1979.
If you are exposed to lead and air sampling
is performed, your employer is required to
quickly notify you in writing of air monitoring results which represent your exposure. If the results indicate your exposure
exceeds the PEL (without regard to your use
of respirators), then your employer must
also notify you of this in writing, and provide you with a description of the corrective
action that will be taken to reduce your exposure.
Your exposure must be rechecked by monitoring every six months if your exposure is
over the action level but below the PEL. Air
monitoring must be repeated every 3 months
if you are exposed over the PEL. Your employer may discontinue monitoring for you if
2 consecutive measurements, taken at least
two weeks apart, are below the action level.
However, whenever there is a production,
process, control, or personnel change at your
workplace which may result in new or additional exposure to lead, or whenever there is
any other reason to suspect a change which
may result in new or additional exposure to
lead, your employer must perform additional
monitoring.
III. METHODS OF COMPLIANCE—PARAGRAPH
(e)
Your employer is required to assure that
no employee is exposed to lead in excess of
the PEL. The standard establishes a priority
of methods to be used to meet the PEL.
IV. RESPIRATORY PROTECTION—PARAGRAPH
(f)
Your employer is required to provide and
assure your use of respirators when your exposure to lead is not controlled below the
PEL by other means. The employer must pay
the cost of the respirator. Whenever you request one, your employer is also required to
provide you a respirator even if your air exposure level does not exceed the PEL. You
might desire a respirator when, for example,
you have received medical advice that your
lead absorption should be decreased. Or, you
may intend to have children in the near future, and want to reduce the level of lead in
your body to minimize adverse reproductive
effects. While respirators are the least satisfactory means of controlling your exposure,
they are capable of providing significant protection if properly chosen, fitted, worn,
cleaned, maintained, and replaced when they
stop providing adequate protection.
Your employer is required to select respirators from the seven types listed in Table
II of the Respiratory Protection section of
the standard (§ 1910.1025(f)). Any respirator
chosen must be approved by the National Institute for Occupational Safety and Health
(NIOSH) under the provisions of 42 CFR part
84. This respirator selection table will enable
your employer to choose a type of respirator
that will give you a proper amount of protection based on your airborne lead exposure.
Your employer may select a type of respirator that provides greater protection than
that required by the standard; that is, one
recommended for a higher concentration of
lead than is present in your workplace. For
example, a powered air-purifying respirator
(PAPR) is much more protective than a typical negative pressure respirator, and may
also be more comfortable to wear. A PAPR
has a filter, cartridge, or canister to clean
the air, and a power source that continuously blows filtered air into your breathing
zone. Your employer might make a PAPR
available to you to ease the burden of having
to wear a respirator for long periods of time.
The standard provides that you can obtain a
PAPR upon request.
Your employer must also start a Respiratory Protection Program. This program
must include written procedures for the
proper selection, use, cleaning, storage, and
maintenance of respirators.
Your employer must ensure that your respirator facepiece fits properly. Proper fit of
a respirator facepiece is critical to your protection from airborne lead. Obtaining a proper fit on each employee may require your
employer to make available several different
types of respirator masks. To ensure that
your respirator fits properly and that facepiece leakage is minimal, your employer
must give you either a qualitative or quantitative fit test as specified in Appendix A of
the Respiratory Protection standard located
at 29 CFR 1910.134.
You must also receive from your employer
proper training in the use of respirators.
Your employer is required to teach you how
to wear a respirator, to know why it is needed, and to understand its limitations.
The standard provides that if your respirator uses filter elements, you must be
given an opportunity to change the filter elements whenever an increase in breathing resistance is detected. You also must be permitted to periodically leave your work area
to wash your face and respirator facepiece
whenever necessary to prevent skin irritation. If you ever have difficulty in breathing
120
during a fit test or while using a respirator,
your employer must make a medical examination available to you to determine whether you can safely wear a respirator. The result of this examination may be to give you
a positive pressure respirator (which reduces
breathing resistance) or to provide alternative means of protection.
V. PROTECTIVE WORK CLOTHING AND
EQUIPMENT—PARAGRAPH (g)
If you are exposed to lead above the PEL,
or if you are exposed to lead compounds such
as lead arsenate or lead azide which can
cause skin and eye irritation, your employer
must provide you with protective work
clothing and equipment appropriate for the
hazard. If work clothing is provided, it must
be provided in a clean and dry condition at
least weekly, and daily if your airborne exposure to lead is greater than 200 µg/m3. Appropriate protective work clothing and
equipment can include coveralls or similar
full-body work clothing, gloves, hats, shoes
or disposable shoe coverlets, and face shields
or vented goggles. Your employer is required
to provide all such equipment at no cost to
you. He is responsible for providing repairs
and replacement as necessary, and also is responsible for the cleaning, laundering or disposal of protective clothing and equipment.
Contaminated work clothing or equipment
must be removed in change rooms and not
worn home or you will extend your exposure
and expose your family since lead from your
clothing can accumulate in your house, car,
etc. Contaminated clothing which is to be
cleaned, laundered or disposed of must be
placed in closed containers in the change
room. At no time may lead be removed from
protective clothing or equipment by any
means which disperses lead into the workroom air.
VI. HOUSEKEEPING—PARAGRAPH
(h)
Your employer must establish a housekeeping program sufficient to maintain all
surfaces as free as practicable of accumulations of lead dust. Vacuuming is the preferred method of meeting this requirement,
and the use of compressed air to clean floors
and other surfaces is absolutely prohibited.
Dry or wet sweeping, shoveling, or brushing
may not be used except where vaccuming or
other equally effective methods have been
tried and do not work. Vacuums must be
used and emptied in a manner which minimizes the reentry of lead into the workplace.
VII. HYGIENE FACILITIES AND PRACTICES—
PARAGRAPH (i)
The standard requires that change rooms,
showers, and filtered air lunchrooms be constructed and made available to workers exposed to lead above the PEL. When the PEL
is exceeded the employer must assure that
§ 1910.1025
food and beverage is not present or consumed, tobacco products are not present or
used, and cosmetics are not applied, except
in these facilities. Change rooms, showers,
and lunchrooms, must be used by workers
exposed in excess of the PEL. After showering, no clothing or equipment worn during
the shift may be worn home, and this includes shoes and underwear. Your own clothing worn during the shift should be carried
home and cleaned carefully so that it does
not contaminate your home. Lunchrooms
may not be entered with protective clothing
or equipment unless surface dust has been
removed by vacuuming, downdraft booth, or
other cleaning method. Finally, workers exposed above the PEL must wash both their
hands and faces prior to eating, drinking,
smoking or applying cosmetics.
All of the facilities and hygiene practices
just discussed are essential to minimize additional sources of lead absorption from inhalation or ingestion of lead that may accumulate on you, your clothes, or your possessions. Strict compliance with these provisions can virtually eliminate several sources
of lead exposure which significantly contribute to excessive lead absorption.
VIII. MEDICAL SURVEILLANCE—PARAGRAPH
(j)
The medical surveillance program is part
of the standard’s comprehensive approach to
the prevention of lead-related disease. Its
purpose is to supplement the main thrust of
the standard which is aimed at minimizing
airborne concentrations of lead and sources
of ingestion. Only medical surveillance can
determine if the other provisions of the
standard have affectively protected you as
an individual. Compliance with the standard’s provision will protect most workers
from the adverse effects of lead exposure, but
may not be satisfactory to protect individual
workers (1) who have high body burdens of
lead acquired over past years, (2) who have
additional uncontrolled sources of non-occupational lead exposure, (3) who exhibit unusual variations in lead absorption rates, or
(4) who have specific non-work related medical conditions which could be aggravated by
lead exposure (e.g., renal disease, anemia). In
addition, control systems may fail, or hygiene and respirator programs may be inadequate. Periodic medical surveillance of individual workers will help detect those failures. Medical surveillance will also be important to protect your reproductive ability—
regardless of whether you are a man or
woman.
All medical surveillance required by the
standard must be performed by or under the
supervision of a licensed physician. The employer must provide required medical surveillance without cost to employees and at a
reasonable time and place. The standard’s
medical surveillance program has two parts-
121
§ 1910.1025
periodic biological monitoring and medical
examinations.
Your employer’s obligation to offer you
medical surveillance is triggered by the results of the air monitoring program. Medical
surveillance must be made available to all
employees who are exposed in excess of the
action level for more than 30 days a year.
The initial phase of the medical surveillance
program, which includes blood lead level
tests and medical examinations, must be
completed for all covered employees no later
than August 28, 1979. Priority within this
first round of medical surveillance must be
given to employees whom the employer believes to be at greatest risk from continued
exposure (for example, those with the longest prior exposure to lead, or those with the
highest current exposure). Thereafter, the
employer must periodically make medical
surveillance—both biological monitoring and
medical examinations—available to all covered employees.
Biological monitoring under the standard
consists of blood lead level (PbB) and zinc
protoporphyrin tests at least every 6 months
after the initial PbB test. A zinc
protoporphyrin (ZPP) test is a very useful
blood test which measures an effect of lead
on your body. Thus biological monitoring
under the standard is currently limited to
PbB testing. If a worker’s PbB exceeds 40 µg/
100g the monitoring frequency must be increased from every 6 months to at least
every 2 months and not reduced until two
consecutive PbBs indicate a blood lead level
below 40 µg/100g. Each time your PbB is determined to be over 40 µg/100g, your employer
must notify you of this in writing within five
working days of his receipt of the test results. The employer must also inform you
that the standard requires temporary medical removal with economic protection when
your PbB exceeds certain criteria. (See Discussion of Medical Removal Protection—
Paragraph (k).) During the first year of the
standard, this removal criterion is 80 µg/100g.
Anytime your PbB exceeds 80 µg/100g your
employer must make available to you a
prompt follow-up PbB test to ascertain your
PbB. If the two tests both exceed 80 µg/100g
and you are temporarily removed, then your
employer must make successive PbB tests
available to you on a monthly basis during
the period of your removal.
Medical examinations beyond the initial
one must be made available on an annual
basis if your blood lead level exceeds 40 µg/
100g at any time during the preceding year.
The initial examination will provide information to establish a baseline to which subsequent data can be compared. An initial
medical examination must also be made
available (prior to assignment) for each employee being assigned for the first time to an
area where the airborne concentration of
lead equals or exceeds the action level. In ad-
dition, a medical examination or consultation must be made available as soon as possible if you notify your employer that you
are experiencing signs or symptoms commonly associated with lead poisoning or that
you have difficulty breathing while wearing
a respirator or during a respirator fit test.
You must also be provided a medical examination or consultation if you notify your
employer that you desire medical advice
concerning the effects of current or past exposure to lead on your ability to procreate a
healthy child.
Finally, appropriate follow-up medical examinations or consultations may also be provided for employees who have been temporarily removed from exposure under the
medical removal protection provisions of the
standard. (See Part IX, below.)
The standard specifies the minimum content of pre-assignment and annual medical
examinations. The content of other types of
medical examinations and consultations is
left up to the sound discretion of the examining physician. Pre-assignment and annual
medical examinations must include (1) a detailed work history and medical history, (2)
a thorough physical examination, and (3) a
series of laboratory tests designed to check
your blood chemistry and your kidney function. In addition, at any time upon your request, a laboratory evaluation of male fertility will be made (microscopic examination
of a sperm sample), or a pregnancy test will
be given.
The standard does not require that you
participate in any of the medical procedures,
tests, etc. which your employer is required
to make available to you. Medical surveillance can, however, play a very important
role in protecting your health. You are
strongly encouraged, therefore, to participate in a meaningful fashion. The standard
contains a multiple physician review mechanism which would give you a chance to have
a physician of your choice directly participate in the medical surveillance program. If
you were dissatisfied with an examination by
a physician chosen by your employer, you
could select a second physician to conduct
an independent analysis. The two doctors
would attempt to resolve any differences of
opinion, and select a third physician to resolve any firm dispute. Generally your employer will choose the physician who conducts medical surveillance under the lead
standard—unless you and your employer can
agree on the choice of a physician or physicians. Some companies and unions have
agreed in advance, for example, to use certain independent medical laboratories or
panels of physicians. Any of these arrangements are acceptable so long as required
medical surveillance is made available to
workers.
The standard requires your employer to
provide certain information to a physician to
122
aid in his or her examination of you. This information includes (1) the standard and its
appendices, (2) a description of your duties as
they relate to lead exposure, (3) your exposure level, (4) a description of personal protective equipment you wear, (5) prior blood
lead level results, and (6) prior written medical opinions concerning you that the employer has. After a medical examination or
consultation the physician must prepare a
written report which must contain (1) the
physician’s opinion as to whether you have
any medical condition which places you at
increased risk of material impairment to
health from exposure to lead, (2) any recommended special protective measures to be
provided to you, (3) any blood lead level determinations, and (4) any recommended limitation on your use of respirators. This last
element must include a determination of
whether you can wear a powered air purifying respirator (PAPR) if you are found unable to wear a negative pressure respirator.
The medical surveillance program of the
lead standard may at some point in time
serve to notify certain workers that they
have acquired a disease or other adverse
medical condition as a result of occupational
lead exposure. If this is true, these workers
might have legal rights to compensation
from public agencies, their employers, firms
that supply hazardous products to their employers, or other persons. Some states have
laws, including worker compensation laws,
that disallow a worker who learns of a jobrelated health impairment to sue, unless the
worker sues within a short period of time
after learning of the impairment. (This period of time may be a matter of months or
years.) An attorney can be consulted about
these possibilities. It should be stressed that
OSHA is in no way trying to either encourage or discourage claims or lawsuits. However, since results of the standard’s medical
surveillance program can significantly affect
the legal remedies of a worker who has acquired a job-related disease or impairment,
it is proper for OSHA to make you aware of
this.
The medical surveillance section of the
standard also contains provisions dealing
with chelation. Chelation is the use of certain drugs (administered in pill form or injected into the body) to reduce the amount
of lead absorbed in body tissues. Experience
accumulated by the medical and scientific
communities has largely confirmed the effectiveness of this type of therapy for the treatment of very severe lead poisoning. On the
other hand, it has also been established that
there can be a long list of extremely harmful
side effects associated with the use of
chelating agents. The medical community
has balanced the advantages and disadvantages resulting from the use of chelating
agents in various circumstances and has established when the use of these agents is ac-
§ 1910.1025
ceptable. The standard includes these accepted limitations due to a history of abuse
of chelation therapy by some lead companies. The most widely used chelating agents
are calcium disodium EDTA, (Ca Na2 EDTA),
Calcium Disodium Versenate (Versenate),
and
d-penicillamine
(pencillamine
or
Cupramine).
The standard prohibits ‘‘prophylactic chelation’’ of any employee by any person the
employer retains, supervises or controls.
‘‘Prophylactic chelation’’ is the routine use
of chelating or similarly acting drugs to prevent elevated blood levels in workers who are
occupationally exposed to lead, or the use of
these drugs to routinely lower blood lead levels to predesignated concentrations believed
to be ‘safe’. It should be emphasized that
where an employer takes a worker who has
no symptoms of lead poisoning and has chelation carried out by a physician (either inside or outside of a hospital) solely to reduce
the worker’s blood lead level, that will generally be considered prophylactic chelation.
The use of a hospital and a physician does
not mean that prophylactic chelation is not
being performed. Routine chelation to prevent increased or reduce current blood lead
levels is unacceptable whatever the setting.
The standard allows the use of ‘‘therapeutic’’ or ‘‘diagnostic’’ chelation if administered under the supervision of a licensed
physician in a clinical setting with thorough
and appropriate medical monitoring. Therapeutic chelation responds to severe lead poisoning where there are marked symptoms.
Diagnostic chelation involved giving a patient a dose of the drug then collecting all
urine excreted for some period of time as an
aid to the diagnosis of lead poisoning.
In cases where the examining physician determines that chelation is appropriate, you
must be notified in writing of this fact before
such treatment. This will inform you of a potentially harmful treatment, and allow you
to obtain a second opinion.
IX. MEDICAL REMOVAL PROTECTION—
PARAGRAPH (k)
Excessive lead absorption subjects you to
increased risk of disease. Medical removal
protection (MRP) is a means of protecting
you when, for whatever reasons, other methods, such as engineering controls, work practices, and respirators, have failed to provide
the protection you need. MRP involves the
temproary removal of a worker from his or
her regular job to a place of significantly
lower exposure without any loss of earnings,
seniority, or other employment rights or
benefits. The purpose of this program is to
cease further lead absorption and allow your
body to naturally excrete lead which has previously been absorbed. Temporary medical
removal can result from an elevated blood
lead level, or a medical opinion. Up to 18
months of protection is provided as a result
123
§ 1910.1025
of either form of removal. The vast majority
of removed workers, however, will return to
their former jobs long before this eighteen
month period expires. The standard contains
special provisions to deal with the extraordinary but possible case where a longterm
worker’s blood lead level does not adequately decline during eighteen months of
removal.
After Mar. 1, 1980 ...............................................
After Mar. 1, 1981 ...............................................
After Mar. 1, 1983 ...............................................
During the first year of the standard, if
your blood lead level is 80 µg/100g or above
you must be removed from any exposure
where your air lead level without a respirator would be 100 µg/m3or above. If you are
removed from your normal job you may not
be returned until your blood lead level declines to at least 60 µg/100g. These criteria
for removal and return will change according
to the following schedule:
Removal blood lead (µg/100
g)
Air lead (µg/m3)
70 and above .........................
60 and above .........................
50 and above averaged over
six months.
50 and above ...........
30 and above ...........
30 and above ...........
You may also be removed from exposure
even if your blood lead levels are below these
criteria if a final medical determination indicates that you temporarily need reduced
lead exposure for medical reasons. If the physician who is implementing your employers
medical program makes a final written opinion recommending your removal or other
special protective measures, your employer
must implement the physician’s recommendation. If you are removed in this
manner, you may only be returned when the
doctor indicates that it is safe for you to do
so.
The standard does not give specific instructions dealing with what an employer
must do with a removed worker. Your job assignment upon removal is a matter for you,
your employer and your union (if any) to
work out consistent with existing procedures
for job assignments. Each removal must be
accomplished in a manner consistent with
existing collective bargaining relationships.
Your employer is given broad discretion to
implement temporary removals so long as no
attempt is made to override existing agreements. Similarly, a removed worker is provided no right to veto an employer’s choice
which satisfies the standard.
In most cases, employers will likely transfer removed employees to other jobs with
sufficiently low lead exposure. Alternatively,
a worker’s hours may be reduced so that the
time weighted average exposure is reduced,
or he or she may be temporarily laid off if no
other alternative is feasible.
In all of these situation, MRP benefits
must be provided during the period of removal—i.e., you continue to receive the
same earnings, seniority, and other rights
and benefits you would have had if you had
not been removed. Earnings includes more
than just your base wage; it includes overtime, shift differentials, incentives, and
other compensation you would have earned if
you had not been removed. During the period
of removal you must also be provided with
Return blood lead
(µg/100 g)
At or below 50.
At or below 40.
Do.
appropriate follow-up medical surveillance.
If you were removed because your blood lead
level was too high, you must be provided
with a monthly blood test. If a medical opinion caused your removal, you must be provided medical tests or examinations that the
doctor believes to be appropriate. If you do
not participate in this follow up medical surveillance, you may lose your eligibility for
MRP benefits.
When you are medically eligible to return
to your former job, your employer must return you to your ‘‘former job status.’’ This
means that you are entitled to the position,
wages, benefits, etc., you would have had if
you had not been removed. If you would still
be in your old job if no removal had occurred
that is where you go back. If not, you are returned consistent with whatever job assignment discretion your employer would have
had if no removal had occurred. MRP only
seeks to maintain your rights, not expand
them or diminish them.
If you are removed under MRP and you are
also eligible for worker compensation or
other compensation for lost wages, your employer’s MRP benefits obligation is reduced
by the amount that you actually receive from
these other sources. This is also true if you
obtain other employment during the time
you are laid off with MRP benefits.
The standard also covers situations where
an employer voluntarily removes a worker
from exposure to lead due to the effects of
lead on the employee’s medical condition,
even though the standard does not require
removal. In these situations MRP benefits
must still be provided as though the standard required removal. Finally, it is important to note that in all cases where removal
is required, respirators cannot be used as a
substitute. Respirators may be used before
removal becomes necessary, but not as an alternative to a transfer to a low exposure job,
or to a lay-off with MRP benefits.
124
X. EMPLOYEE INFORMATION AND TRAINING—
PARAGRAPH (l)
Your employer is required to provide an information and training program for all employees exposed to lead above the action
level or who may suffer skin or eye irritation
from lead. This program must inform these
employees of the specific hazards associated
with their work environment, protective
measures which can be taken, the danger of
lead to their bodies (including their reproductive systems), and their rights under the
standard. In addition your employer must
make readily available to all employees, including those exposed below the action level,
a copy of the standard and its appendices and
must distribute to all employees any materials provided to the employer by the Occupational Safety and Health Administration
(OSHA).
Your employer is required to complete this
training program for all employees by August 28, 1979. After this date, all new employees must be trained prior to initial assignment to areas where there is a possibility of
exposure over the action level.
This training program must also be provided at least annually thereafter.
XI. SIGNS—PARAGRAPH
(m)
The standard requires that the following
warning sign be posted in work areas where
the exposure to lead exceeds the PEL:
WARNING
LEAD WORK AREA
each medical removal record only for as long
as the duration of an employee’s employment.
The standard requires that if you request
to see or copy environmental monitoring,
blood lead level monitoring, or medical removal records, they must be made available
to you or to a representative that you authorize. Your union also has access to these
records. Medical records other than PbB’s
must also be provided upon request to you,
to your physician or to any other person
whom you may specifically designate. Your
union does not have access to your personal
medical records unless you authorize their
access.
XIII. OBSERVATIONS OF MONITORING—
PARAGRAPH (o)
When air monitoring for lead is performed
at your workplace as required by this standard, your employer must allow you or someone you designate to act as an observer of
the monitoring. Observers are entitled to an
explanation of the measurement procedure,
and to record the results obtained. Since results will not normally be available at the
time of the monitoring, observers are entitled to record or receive the results of the
monitoring when returned by the laboratory.
Your employer is required to provide the observer with any personal protective devices
required to be worn by employees working in
the area that is being monitored. The employer must require the observer to wear all
such equipment and to comply with all other
applicable safety and health procedures.
XII. RECORDKEEPING—PARAGRAPH
§ 1910.1025
XIV. EFFECTIVE DATE—PARAGRAPH
(n)
Your employer is required to keep all
records of exposure monitoring for airborne
lead. These records must include the name
and job classification of employees measured, details of the sampling and analytic
techniques, the results of this sampling, and
the type of respiratory protection being
worn by the person sampled. Your employer
is also required to keep all records of biological monitoring and medical examination results. These must include the names of the
employees, the physician’s written opinion,
and a copy of the results of the examination.
All of the above kinds of records must be
kept for 40 years, or for at least 20 years
after your termination of employment,
whichever is longer.
Recordkeeping is also required if you are
temporarily removed from your job under
the medical removal protection program.
This record must include your name and social security number, the date of your removal and return, how the removal was or is
being accomplished, and whether or not the
reason for the removal was an elevated blood
lead level. Your employer is required to keep
(p)
The standard’s effective data is March 1,
1979, and employer obligations under the
standard begin to come into effect as of that
date.
XV. FOR ADDITIONAL INFORMATION
A. Copies of the Standard and explanatory
material may be obtained by writing or calling the OSHA Docket Office, U.S. Department of Labor, room N2634, 200 Constitution
Avenue, N.W., Washington, DC 20210. Telephone: (202) 219–7894.
1. The standard and summary of the statement of reasons (preamble), FEDERAL REGISTER, Volume 43, pp. 52952–53014, November
14, 1978.
2. The full statement of reasons (preamble)
FEDERAL REGISTER, vol. 43, pp. 54354–54509,
November 21, 1978.
3. Partial Administrative Stay and Corrections to the standard, (44 FR 5446–5448) January 26, 1979.
4. Notice of the Partial Judicial Stay (44
FR 14554–14555) March 13, 1979.
5. Corrections to the preamble, FEDERAL
REGISTER, vol. 44, pp. 20680–20681, April 6,
1979.
125
§ 1910.1025
6. Additional correction to the preamble
concerning the construction industry, FEDERAL REGISTER, vol. 44, p. 50338, August 28,
1979.
7. Appendices to the standard (Appendices
A, B, C), FEDERAL REGISTER, Vol. 44, pp.
60980–60995, October 23, 1979.
8. Corrections to appendices, FEDERAL REGISTER, Vol. 44, 68828, November 30, 1979.
9. Revision to the standard and an additional appendix (Appendix D), FEDERAL REGISTER, Vol. 47, pp. 51117–51119, November 12,
1982.
10. Notice of reopening of lead rulemaking
for nine remand industry sectors, FEDERAL
REGISTER, vol. 53, pp. 11511–11513, April 7,
1988.
11. Statement of reasons, FEDERAL REGISTER, vol. 54, pp. 29142–29275, July 11, 1989.
12. Statement of reasons, FEDERAL REGISTER, vol. 55, pp. 3146–3167, January 30, 1990.
13. Correction to appendix B, FEDERAL
REGISTER, vol. 55, pp. 4998–4999, February 13,
1991.
14. Correction to appendices, FEDERAL REGISTER, vol. 56, p. 24686, May 31, 1991.
B. Additional information about the standard, its enforcement, and your employer’s
compliance can be obtained from the nearest
OSHA Area Office listed in your telephone
directory under United States Government/
Department of Labor.
SURVEILLANCE GUIDELINES
INTRODUCTION
The primary purpose of the Occupational
Safety and Health Act of 1970 is to assure, so
far as possible, safe and healthful working
conditions for every working man and
woman. The occupational health standard
for inorganic lead1 was promulgated to protect workers exposed to inorganic lead including metallic lead, all inorganic lead
compounds and organic lead soaps.
Under this final standard in effect as of
March 1, 1979, occupational exposure to inorganic lead is to be limited to 50 µg/m3
(micrograms per cubic meter) based on an 8
hour time-weighted average (TWA). This
level of exposure eventually must be
achieved through a combination of engineering, work practice and other administrative
controls. Periods of time ranging from 1 to 10
years are provided for different industries to
implement these controls. The schedule
which is based on individual industry considerations is given in Table 1. Until these controls are in place, respirators must be used
to meet the 50 µg/m3 exposure limit.
The standard also provides for a program
of biological monitoring and medical surveillance for all employees exposed to levels of
inorganic lead above the action level of 30 µg/
m3 (TWA) for more than 30 days per year.
The purpose of this document is to outline
the medical surveillance provisions of the
standard for inorganic lead, and to provide
further information to the physician regarding the examination and evaluation of workers exposed to inorganic lead.
Section 1 provides a detailed description of
the monitoring procedure including the required frequency of blood testing for exposed
workers, provisions for medical removal protection (MRP), the recommended right of the
employee to a second medical opinion, and
notification and recordkeeping requirements
of the employer. A discussion of the requirements for respirator use and respirator monitoring and OSHA’s position on prophylactic
chelation therapy are also included in this
section.
Section 2 discusses the toxic effects and
clinical manifestations of lead poisoning and
effects of lead intoxication on enzymatic
pathways in heme synthesis. The adverse effects on both male and female reproductive
capacity and on the fetus are also discussed.
Section 3 outlines the recommended medical evaluation of the worker exposed to inorganic lead including details of the medical
history, physical examination, and recommended laboratory tests, which are based
on the toxic effects of lead as discussed in
Section 2.
Section 4 provides detailed information
concerning the laboratory tests available for
the monitoring of exposed workers. Included
also is a discussion of the relative value of
each test and the limitations and precautions which are necessary in the interpretation of the laboratory results.
TABLE 1
Effective date
Permissible airborne lead levels by industry (µg/m3) 1
1.
2.
3.
4.
Mar. 1,
1979
Primary lead production ........................................................
Secondary lead production ...................................................
Lead-acid battery manufacturing ..........................................
Nonferrous foundries ............................................................
1 The term inorganic lead used throughout
the medical surveillance appendices is meant
200
200
200
200
Mar. 1,
1980
200
200
200
100
Mar. 1,
1981
200
200
100
100
Mar. 1,
1982
100
100
100
100
Mar. 1,
1984
100
50
50
50
Mar. 1,
1989
(final)
50
50
50
50
to be synonymous with the definition of lead
set forth in the standard.
126
§ 1910.1025
TABLE 1—Continued
Effective date
Permissible airborne lead levels by industry (µg/m3) 1
Mar. 1,
1979
5. Lead pigment manufacturing ................................................
6. All other industries ................................................................
200
200
Mar. 1,
1980
Mar. 1,
1981
200
50
Mar. 1,
1982
200
50
Mar. 1,
1984
100
50
Mar. 1,
1989
(final)
50
50
50
50
1 Airborne levels to be achieved without reliance or respirator protection through a combination of engineering, work practice
and other administrative controls. While these controls are being implemented respirators must be used to meet the 50 µg/m3
exposure limit.
I. MEDICAL SURVEILLANCE AND MONITORING REQUIREMENTS FOR WORKERS EXPOSED TO INORGANIC LEAD
Under the occupational health standard for
inorganic lead, a program of biological monitoring and medical surveillance is to be
made available to all employees exposed to
lead above the action level of 30 µg/m3 TWA
for more than 30 days each year. This program consists of periodic blood sampling and
medical evaluation to be performed on a
schedule which is defined by previous laboratory results, worker complaints or concerns,
and the clinical assessment of the examining
physician.
Under this program, the blood lead level of
all employees who are exposed to lead above
the action level of 30 µg/m3 is to be determined at least every six months. The frequency is increased to every two months for
employees whose last blood lead level was
between 40 µ g/100 g whole blood and the level
requiring employee medical removal to be
discussed below. For employees who are removed from exposure to lead due to an elevated blood lead, a new blood lead level must
be measured monthly. A zinc protoporphyrin
(ZPP) is required on each occasion that a
blood lead level measurement is made.
An annual medical examination and consultation performed under the guidelines discussed in Section 3 is to be made available to
each employee for whom a blood test conducted at any time during the preceding 12
months indicated a blood lead level at or
above 40 µ g/100 g. Also, an examination is to
be given to all employees prior to their assignment to an area in which airborne lead
concentrations reach or exceed the action
level. In addition, a medical examination
must be provided as soon as possible after
notification by an employee that the employee has developed signs or symptoms
commonly associated with lead intoxication,
that the employee desires medical advice regarding lead exposure and the ability to procreate a healthy child, or that the employee
has demonstrated difficulty in breathing
during a respirator fitting test or during respirator use. An examination is also to be
made available to each employee removed
from exposure to lead due to a risk of sustaining material impairment to health, or
otherwise limited or specially protected pursuant to medical recommendations.
Results of biological monitoring or the recommendations of an examining physician
may necessitate removal of an employee
from further lead exposure pursuant to the
standard’s
medical
removal
protection
(MRP) program. The object of the MRP program is to provide temporary medical removal to workers either with substantially
elevated blood lead levels or otherwise at
risk of sustaining material health impairment from continued substantial exposure to
lead. The following guidelines which are
summarized in Table 2 were created under
the standard for the temporary removal of
an exposed employee and his or her subsequent return to work in an exposure area.
TABLE 2
Effective date
A. Blood lead level requiring employee medical removal. (Level
must be confirmed with second
follow-up blood lead level within
two weeks of first report.).
Mar. 1, 1979
Mar. 1, 1980
Mar. 1, 1981
Mar. 1, 1982
Mar. 1, 1983 (final)
≥80 µg/100 g
≥70µg/100 g
≥60 µg/100 g
≥60 µg/100 g
≥60µg/100 g or average of
last three blood samples
or all blood samples
over previous 6 months
(whichever is over a
longer time period) is 50
µg/100 g or greater unless last blood sample is
40 µg/100 g or less.
127
§ 1910.1025
TABLE 2—Continued
Effective date
B. Frequency which employees exposed to action level of lead (30
µg/m3 TWA) must have blood
lead level checked (ZPP is also
required in each occasion that a
blood lead is obtained.):
1. Last blood lead level less
than 40 µg/100 g.
2. Last blood lead level between 40 µg/100 g and level
requiring medical removal
(see A above).
3. Employees removed from
exposure to lead because of
an elevated blood lead level.
C. Permissible airborne exposure
limit for workers removed from
work due to an elevated blood
lead level (without regard to respirator protection).
D. Blood lead level confirmed with
a second blood analysis, at
which employee may return to
work. Permissible exposure without regard to respirator protection is listed by industry in Table
I.
Mar. 1, 1979
Mar. 1, 1980
Mar. 1, 1981
Mar. 1, 1982
Mar. 1, 1983 (final)
Every 6
months
Every 2
months
Every 6
months
Every 2
months
Every 6
months
Every 2
months
Every 6
months
Every 2
months
Every 6 months.
Every 1
month
Every 1
month
Every 1
month
Every 1
month
Every 1 month.
100 µg/m3 8
hr TWA
50 µg/m3 8
hr TWA
30 µg/m3 8
hr TWA
30 µg/m3 8
hr TWA
30 µg/m3 8 hr TWA.
·60 µg/100 g
·50 µg/100 g
·40 µg/100 g
·40 µg/100 g
·40 µg/100 g.
Every 2 months.
NOTE: When medical opinion indicates that an employee is at risk of material impairment from exposure to lead, the physician
can remove an employee from exposures exceeding the action level (or less) or recommend special protective measures as
deemed appropriate and necessary. Medical monitoring during the medical removal period can be more stringent than noted in
the table above if the physician so specifies. Return to work or removal of limitations and special protections is permitted when
the physician indicates that the worker is no longer at risk of material impairment.
Under the standard’s ultimate worker removal criteria, a worker is to be removed
from any work having any eight hour TWA
exposure to lead of 30 µg/m3 or more whenever either of the following circumstances
apply: (1) a blood lead level of 60 µ g/100 g or
greater is obtained and confirmed by a second follow-up blood lead level performed
within two weeks after the employer receives the results of the first blood sampling
test, or (2) the average of the previous three
blood lead determinations or the average of
all blood lead determinations conducted during the previous six months, whichever encompasses the longest time period, equals or
exceeds 50 µ g/100 g, unless the last blood
sample indicates a blood lead level at or
below 40 µ g/100 g in which case the employee
need not be removed. Medical removal is to
continue until two consecutive blood lead
levels are 40 µ g/100 g or less.
During the first two years that the ultimate removal criteria are being phased in,
the return criteria have been set to assure
that a worker’s blood lead level has substantially declined during the period of removal.
From March 1, 1979 to March 1, 1980, the
blood lead level requiring employee medical
removal is 80 µ g/100 g. Workers found to
have a confirmed blood lead at this level or
greater need only be removed from work
having a daily 8 hour TWA exposure to lead
at or above 100 µg/m3. Workers so removed
are to be returned to work when their blood
lead levels are at or below 60 µ g/100 g of
whole blood. From March 1, 1980 to March 1,
1981, the blood lead level requiring medical
removal is 70 µ g/100 g. During this period
workers need only be removed from jobs having a daily 8 hour TWA exposure to lead at
or above 50 µg/m3 and are to be returned to
work when a level of 50 µ g/100 g is achieved.
Beginning March 1, 1981, return depends on a
worker’s blood lead level declining to 40 µ g/
100 g of whole blood.
As part of the standard, the employer is required to notify in writing each employee
whose blood lead level exceeds 40 µ g/100 g. In
addition each such employee is to be informed that the standard requires medical
removal with MRP benefits, discussed below,
when an employee’s blood lead level exceeds
the above defined limits.
In addition to the above blood lead level
criteria, temporary worker removal may
also take place as a result of medical determinations and recommendations. Written
medical opinions must be prepared after
each examination pursuant to the standard.
If the examining physician includes a medical finding, determination or opinion that
the employee has a medical condition which
128
places the employee at increased risk of material health impairment from exposure to
lead, then the employee must be removed
from exposure to lead at or above the action
level. Alternatively, if the examining physician recommends special protective measures for an employee (e.g., use of a powered
air purifying respirator) or recommends limitations on an employee’s exposure to lead,
then the employer must implement these
recommendations. Recommendations may be
more stringent than the specific provisions
of the standard. The examining physician,
therefore, is given broad flexibility to tailor
special protective procedures to the needs of
individual employees. This flexibility extends to the evaluation and management of
pregnant workers and male and female workers who are planning to raise children. Based
on the history, physical examination, and
laboratory studies, the physician might recommend special protective measures or medical removal for an employee who is pregnant or who is planning to conceive a child
when, in the physician’s judgment, continued exposure to lead at the current job would
pose a significant risk. The return of the employee to his or her former job status, or the
removal of special protections or limitations, depends upon the examining physician
determining that the employee is no longer
at increased risk of material impairment or
that special measures are no longer needed.
During the period of any form of special
protection or removal, the employer must
maintain the worker’s earnings, seniority,
and other employment rights and benefits
(as though the worker had not been removed)
for a period of up to 18 months. This economic protection will maximize meaningful
worker participation in the medical surveillance program, and is appropriate as part of
the employer’s overall obligation to provide
a safe and healthful workplace. The provisions of MRP benefits during the employee’s
removal period may, however, be conditioned
upon participation in medical surveillance.
On rare occasions, an employee’s blood
lead level may not acceptably decline within
18 months of removal. This situation will
arise only in unusual circumstances, thus
the standard relies on an individual medical
examination to determine how to protect
such an employee. This medical determination is to be based on both laboratory values,
including lead levels, zinc protoporphyrin
levels, blood counts, and other tests felt to
be warranted, as well as the physician’s judgment that any symptoms or findings on
physical examination are a result of lead
toxicity. The medical determination may be
that the employee is incapable of ever safely
returning to his or her former job status.
The medical determination may provide additional removal time past 18 months for
some employees or specify special protective
measures to be implemented.
§ 1910.1025
The lead standard provides for a multiple
physician review in cases where the employee wishes a second opinion concerning
potential lead poisoning or toxicity. If an
employee wishes a second opinion, he or she
can make an appointment with a physician
of his or her choice. This second physician
will review the findings, recommendations or
determinations of the first physician and
conduct any examinations, consultations or
tests deemed necessary in an attempt to
make a final medical determination. If the
first and second physicians do not agree in
their assessment they must try to resolve
their differences. If they cannot reach an
agreement then they must designate a third
physician to resolve the dispute.
The employer must provide examining and
consulting physicians with the following specific information: a copy of the lead regulations and all appendices, a description of the
employee’s duties as related to exposure, the
exposure level to lead and any other toxic
substances (if applicable), a description of
personal protective equipment used, blood
lead levels, and all prior written medical
opinions regarding the employee in the employer’s possession or control. The employer
must also obtain from the physician and provide the employee with a written medical
opinion containing blood lead levels, the
physicians’s opinion as to whether the employee is at risk of material impairment to
health, any recommended protective measures for the employee if further exposure is
permitted, as well as any recommended limitations upon an employee’s use of respirators.
Employers must instruct each physician
not to reveal to the employer in writing or
in any other way his or her findings, laboratory results, or diagnoses which are felt to
be unrelated to occupational lead exposure.
They must also instruct each physician to
advise the employee of any occupationally or
non-occupationally related medical condition requiring further treatment or evaluation.
The standard provides for the use of respirators where engineering and other primary controls have not been fully implemented. However, the use of respirator protection shall not be used in lieu of temporary
medical removal due to elevated blood lead
levels or findings that an employee is at risk
of material health impairment. This is based
on the numerous inadequacies of respirators
including skin rash where the facepiece
makes contact with the skin, unacceptable
stress to breathing in some workers with underlying cardiopulmonary impairment, difficulty in providing adequate fit, the tendency for respirators to create additional hazards by interfering with vision, hearing, and
mobility, and the difficulties of assuring the
maximum effectiveness of a complicated
work practice program involving respirators.
129
§ 1910.1025
Respirators do, however, serve a useful function where engineering and work practice
controls are inadequate by providing supplementary, interim, or short-term protection,
provided they are properly selected for the
environment in which the employee will be
working, properly fitted to the employee,
maintained and cleaned periodically, and
worn by the employee when required.
In its final standard on occupational exposure to inorganic lead, OSHA has prohibited
prophylactic chelation. Diagnostic and
therapeutic chelation are permitted only
under the supervision of a licensed physician
with appropriate medical monitoring in an
acceptable clinical setting. The decision to
initiate chelation therapy must be made on
an individual basis and take into account the
severity of symptoms felt to be a result of
lead toxicity along with blood lead levels,
ZPP levels, and other laboratory tests as appropriate. EDTA and penicillamine which
are the primary chelating agents used in the
therapy of occupational lead poisoning have
significant potential side effects and their
use must be justified on the basis of expected
benefits to the worker. Unless frank and severe symptoms are present, therapeutic chelation is not recommended given the opportunity to remove a worker from exposure
and allow the body to naturally excrete accumulated lead. As a diagnostic aid, the chelation mobilization test using CA–EDTA has
limited applicability. According to some investigators, the test can differentiate between lead-induced and other nephropathies.
The test may also provide an estimation of
the mobile fraction of the total body lead
burden.
Employers are required to assure that accurate records are maintained on exposure
monitoring, medical surveillance, and medical removal for each employee. Exposure
monitoring and medical surveillance records
must be kept for 40 years or the duration of
employment plus 20 years, whichever is
longer, while medical removal records must
be maintained for the duration of employment. All records required under the standard must be made available upon request to
the Assistant Secretary of Labor for Occupational Safety and Health and the Director of
the National Institute for Occupational Safety and Health. Employers must also make
environmental and biological monitoring
and medical removal records available to affected employees and to former employees or
their authorized employee representatives.
Employees or their specifically designated
representatives have access to their entire
medical surveillance records.
In addition, the standard requires that the
employer inform all workers exposed to lead
at or above the action level of the provisions
of the standard and all its appendices, the
purpose and description of medical surveillance and provisions for medical removal
protection if temporary removal is required.
An understanding of the potential health effects of lead exposure by all exposed employees along with full understanding of their
rights under the lead standard is essential
for an effective monitoring program.
II. ADVERSE HEALTH EFFECTS OF INORGANIC
LEAD
Although the toxicity of lead has been
known for 2,000 years, the knowledge of the
complex relationship between lead exposure
and human response is still being refined.
Significant research into the toxic properties of lead continues throughout the
world, and it should be anticipated that our
understanding of thresholds of effects and
margins of safety will be improved in future
years. The provisions of the lead standard
are founded on two prime medical judgments: first, the prevention of adverse health
effects from exposure to lead throughout a
working lifetime requires that worker blood
lead levels be maintained at or below 40 µ g/
100 g and second, the blood lead levels of
workers, male or female, who intend to parent in the near future should be maintained
below 30 µ g/100 g to minimize adverse reproductive health effects to the parents and developing fetus. The adverse effects of lead on
reproduction are being actively researched
and OSHA encourages the physician to remain abreast of recent developments in the
area to best advise pregnant workers or
workers planning to conceive children.
The spectrum of health effects caused by
lead exposure can be subdivided into five developmental stages: normal, physiological
changes
of
uncertain
significance,
pathophysiological changes, overt symptoms
(morbidity), and mortality. Within this process there are no sharp distinctions, but rather a continuum of effects. Boundaries between categories overlap due to the wide variation of individual responses and exposures
in the working population. OSHA’s development of the lead standard focused on
pathophysiological changes as well as later
stages of disease.
1. Heme Synthesis Inhibition. The earliest
demonstrated effect of lead involves its ability to inhibit at least two enzymes of the
heme synthesis pathway at very low blood
levels. Inhibition of delta aminolevulinic
acid dehydrase (ALA–D) which catalyzes the
conversion of delta-aminolevulinic acid
(ALA) to protoporphyrin is observed at a
blood lead level below 20 µ g/100 g whole
blood. At a blood lead level of 40 ug/100 g,
more than 20% of the population would have
70% inhibition of ALA–D. There is an exponential increase in ALA excretion at blood
lead levels greater than 40 µ g/100 g.
Another enzyme, ferrochelatase, is also inhibited at low blood lead levels. Inhibition of
ferrochelatase leads to increased free erythrocyte protoporphyrin (FEP) in the blood
130
which can then bind to zinc to yield zinc
protoporphyrin. At a blood lead level of 50 µ
g/100 g or greater, nearly 100% of the population will have an increase in FEP. There is
also an exponential relationship between
blood lead levels greater than 40 µ g/100 g and
the associated ZPP level, which has led to
the development of the ZPP screening test
for lead exposure.
While the significance of these effects is
subject to debate, it is OSHA’s position that
these enzyme disturbances are early stages
of a disease process which may eventually
result in the clinical symptoms of lead poisoning. Whether or not the effects do
progress to the later stages of clinical disease, disruption of these enzyme processes
over a working lifetime is considered to be a
material impairment of health.
One of the eventual results of lead-induced
inhibition of enzymes in the heme synthesis
pathway is anemia which can be asymptomatic if mild but associated with a wide
array of symptoms including dizziness, fatigue, and tachycardia when more severe.
Studies have indicated that lead levels as
low as 50 µ g/100 g can be associated with a
definite decreased hemoglobin, although
most cases of lead-induced anemia, as well as
shortened red-cell survival times, occur at
lead levels exceeding 80 µ g/100 g. Inhibited
hemoglobin synthesis is more common in
chronic cases whereas shortened erythrocyte
life span is more common in acute cases.
In lead-induced anemias, there is usually a
reticulocytosis along with the presence of
basophilic stippling, and ringed sideroblasts,
although
none
of
the
above
are
pathognomonic for lead-induced anemia.
2. Neurological Effects. Inorganic lead has
been found to have toxic effects on both the
central and peripheral nervous systems. The
earliest stages of lead-induced central nervous system effects first manifest themselves
in the form of behavioral disturbances and
central nervous system symptoms including
irritability, restlessness, insomnia and other
sleep disturbances, fatigue, vertigo, headache, poor memory, tremor, depression, and
apathy. With more severe exposure, symptoms can progress to drowsiness, stupor, hallucinations, delerium, convulsions and coma.
The most severe and acute form of lead
poisoning which usually follows ingestion or
inhalation of large amounts of lead is acute
encephalopathy which may arise precipitously with the onset of intractable seizures,
coma, cardiorespiratory arrest, and death
within 48 hours.
While there is disagreement about what exposure levels are needed to produce the earliest symptoms, most experts agree that
symptoms definitely can occur at blood lead
levels of 60 µ g/100 g whole blood and therefore recommend a 40 µ g/100 g maximum. The
central nervous system effects frequently are
not reversible following discontinued expo-
§ 1910.1025
sure or chelation therapy and when improvement does occur, it is almost always only
partial.
The peripheral neuropathy resulting from
lead exposure characteristically involves
only motor function with minimal sensory
damage and has a marked predilection for
the extensor muscles of the most active extremity. The peripheral neuropathy can
occur with varying degrees of severity. The
earliest and mildest form which can be detected in workers with blood lead levels as
low as 50 µ g/100 g is manifested by slowing
of motor nerve conduction velocity often
without clinical symptoms. With progression
of the neuropathy there is development of
painless extensor muscle weakness usually
involving the extensor muscles of the fingers
and hand in the most active upper extremity, followed in severe cases by wrist drop or,
much less commonly, foot drop.
In addition to slowing of nerve conduction,
electromyographical studies in patients with
blood lead levels greater than 50 µ g/100 g
have demonstrated a decrease in the number
of acting motor unit potentials, an increase
in the duration of motor unit potentials, and
spontaneous pathological activity including
fibrillations and fasciculations. Whether
these effects occur at levels of 40 µ g/100 g is
undetermined.
While the peripheral neuropathies can occasionally be reversed with therapy, again
such recovery is not assured particularly in
the more severe neuropathies and often improvement is only partial. The lack of reversibility is felt to be due in part to segmental demyelination.
3. Gastrointestinal. Lead may also affect the
gastrointestinal system producing abdominal colic or diffuse abdominal pain, constipation, obstipation, diarrhea, anorexia,
nausea and vomiting. Lead colic rarely develops at blood lead levels below 80 µ g/100 g.
4. Renal. Renal toxicity represents one of
the most serious health effects of lead poisoning. In the early stages of disease nuclear
inclusion bodies can frequently be identified
in proximal renal tubular cells. Renal function remains normal and the changes in this
stage are probably reversible. With more advanced disease there is progressive interstitial fibrosis and impaired renal function.
Eventually extensive interstitial fibrosis ensues with sclerotic glomeruli and dilated and
atrophied proximal tubules; all represent end
stage kidney disease. Azotemia can be progressive, eventually resulting in frank uremia necessitating dialysis. There is occasionally
associated
hypertension
and
hyperuricemia with or without gout.
Early kidney disease is difficult to detect.
The urinalysis is normal in early lead
nephropathy and the blood urea nitrogen and
serum creatinine increase only when two-
131
§ 1910.1025
thirds of kidney function is lost. Measurement of creatinine clearance can often detect earlier disease as can other methods of
measurement of glomerular filtration rate.
An abnormal Ca-EDTA mobilization test has
been used to differentiate between lead-induced and other nephropathies, but this procedure is not widely accepted. A form of
Fanconi syndrome with aminoaciduria,
glycosuria, and hyperphosphaturia indicating severe injury to the proximal renal
tubules is occasionally seen in children.
5. Reproductive effects. Exposure to lead can
have serious effects on reproductive function
in both males and females. In male workers
exposed to lead there can be a decrease in
sexual drive, impotence, decreased ability to
produce healthy sperm, and sterility. Malformed sperm (teratospermia), decreased
number of sperm (hypospermia), and sperm
with decreased motility (asthenospermia)
can all occur. Teratospermia has been noted
at mean blood lead levels of 53 µ g/100 g and
hypospermia and asthenospermia at 41 µ g/
100 g. Furthermore, there appears to be a
dose-response relationship for teratospermia
in lead exposed workers.
Women exposed to lead may experience
menstrual
disturbances
including
dysmenorrhea, menorrhagia and amenorrhea. Following exposure to lead, women
have a higher frequency of sterility, premature births, spontaneous miscarriages,
and stillbirths.
Germ cells can be affected by lead and
cause genetic damage in the egg or sperm
cells before conception and result in failure
to implant, miscarriage, stillbirth, or birth
defects.
Infants of mothers with lead poisoning
have a higher mortality during the first year
and suffer from lowered birth weights, slower
growth, and nervous system disorders.
Lead can pass through the placental barrier and lead levels in the mother’s blood are
comparable to concentrations of lead in the
umbilical cord at birth. Transplacental passage becomes detectable at 12–14 weeks of
gestation and increases until birth.
There is little direct data on damage to the
fetus from exposure to lead but it is generally assumed that the fetus and newborn
would be at least as susceptible to neurological damage as young children. Blood lead
levels of 50–60 µ g/100 g in children can cause
significant neurobehavioral impairments and
there is evidence of hyperactivity at blood
levels as low as 25 µ g/100 g. Given the overall
body of literature concerning the adverse
health effects of lead in children, OSHA feels
that the blood lead level in children should
be maintained below 30 µ g/100 g with a population mean of 15 µ g/100 g. Blood lead levels
in the fetus and newborn likewise should not
exceed 30 µ g/100 g.
Because of lead’s ability to pass through
the placental barrier and also because of the
demonstrated adverse effects of lead on reproductive function in both the male and female as well as the risk of genetic damage of
lead on both the ovum and sperm, OSHA recommends a 30 µ g/100 g maximum permissible
blood lead level in both males and females
who wish to bear children.
6. Other toxic effects. Debate and research
continue on the effects of lead on the human
body. Hypertension has frequently been
noted in occupationally exposed individuals
although it is difficult to assess whether this
is due to lead’s adverse effects on the kidney
or if some other mechanism is involved. Vascular and electrocardiogarphic changes have
been detected but have not been well characterized. Lead is thought to impair thyroid
function and interfere with the pituitary-adrenal axis, but again these effects have not
been well defined.
III. MEDICAL EVALUATION
The most important principle in evaluating a worker for any occupational disease
including lead poisoning is a high index of
suspicion on the part of the examining physician. As discussed in Section 2, lead can affect numerous organ systems and produce a
wide array of signs and symptoms, most of
which are non-specific and subtle in nature
at least in the early stages of disease. Unless
serious concern for lead toxicity is present,
many of the early clues to diagnosis may
easily be overlooked.
The crucial initial step in the medical
evaluation is recognizing that a worker’s
employment can result in exposure to lead.
The worker will frequently be able to define
exposures to lead and lead containing materials but often will not volunteer this information unless specifically asked. In other
situations the worker may not know of any
exposures to lead but the suspicion might be
raised on the part of the physician because of
the industry or occupation of the worker.
Potential occupational exposure to lead and
its compounds occur in at least 120 occupations, including lead smelting, the manufacture of lead storage batteries, the manufacture of lead pigments and products containing pigments, solder manufacture, shipbuilding and ship repair, auto manufacturing, construction, and painting.
Once the possibility for lead exposure is
raised, the focus can then be directed toward
eliciting information from the medical history, physical exam, and finally from laboratory data to evaluate the worker for potential lead toxicity.
A complete and detailed work history is
important in the initial evaluation. A listing
of all previous employment with information
on work processes, exposure to fumes or
dust, known exposures to lead or other toxic
substances, respiratory protection used, and
previous medical surveillance should all be
132
included in the worker’s record. Where exposure to lead is suspected, information concerning on-the-job personal hygiene, smoking or eating habits in work areas, laundry
procedures, and use of any protective clothing or respiratory protection equipment
should be noted. A complete work history is
essential in the medical evaluation of a
worker with suspected lead toxicity, especially when long term effects such as
neurotoxicity and nephrotoxicity are considered.
The medical history is also of fundamental
importance and should include a listing of
all past and current medical conditions, current medications including proprietary drug
intake, previous surgeries and hospitalizations, allergies, smoking history, alcohol
consumption, and also non-occupational lead
exposures such as hobbies (hunting, riflery).
Also known childhood exposures should be
elicited.
Any
previous
history
of
hematological,
neurological,
gastrointestinal, renal, psychological, gynecological, genetic, or reproductive problems
should be specifically noted.
A careful and complete review must be performed to assess both recognized complaints
and subtle or slowly acquired symptoms
which the worker might not appreciate as
being significant. The review of symptoms
should include the following:
General—weight loss, fatigue, decreased
appetite.
Head, Eyes, Ears, Nose, Throat (HEENT)—
headaches, visual disturbances or decreased
visual acuity, hearing deficits or tinnitus,
pigmentation of the oral mucosa, or metallic
taste in mouth.
Cardio-pulmonary—shortness of breath,
cough, chest pains, palpitations, or orthopnea.
Gastrointestinal—nausea, vomiting, heartburn, abdominal pain, constipation or diarrhea.
Neurologic—irritability, insomnia, weakness (fatigue), dizziness, loss of memory, confusion, hallucinations, incoordination, ataxia, decreased strength in hands or feet, disturbances in gait, difficulty in climbing
stairs, or seizures.
Hematologic—pallor, easy fatigability, abnormal blood loss, melena.
Reproductive (male and female and spouse
where relevant)—history of infertility, impotence, loss of libido, abnormal menstrual periods, history of miscarriages, stillbirths, or
children with birth defects.
Musculo-skeletal—muscle and joint pains.
The physical examination should emphasize the neurological, gastrointestinal, and
cardiovascular systems. The worker’s weight
and blood pressure should be recorded and
the oral mucosa checked for pigmentation
characteristic of a possible Burtonian or lead
line on the gingiva. It should be noted, how-
§ 1910.1025
ever, that the lead line may not be present
even in severe lead poisoning if good oral hygiene is practiced.
The presence of pallor on skin examination
may indicate an anemia, which if severe
might also be associated with a tachycardia.
If an anemia is suspected, an active search
for blood loss should be undertaken including potential blood loss through the gastrointestinal tract.
A complete neurological examination
should include an adequate mental status
evaluation including a search for behavioral
and psychological disturbances, memory
testing, evaluation for irritability, insomnia,
hallucinations, and mental clouding. Gait
and coordination should be examined along
with close observation for tremor. A detailed
evaluation of peripheral nerve function including careful sensory and motor function
testing is warranted. Strength testing particularly of extensor muscle groups of all extremities is of fundamental importance.
Cranial nerve evaluation should also be included in the routine examination.
The abdominal examination should include
auscultation for bowel sounds and abdominal
bruits and palpation for organomegaly,
masses, and diffuse abdominal tenderness.
Cardiovascular examination should evaluate possible early signs of congestive heart
failure. Pulmonary status should be addressed particularly if respirator protection
is contemplated.
As part of the medical evaluation, the lead
standard requires the following laboratory
studies:
1. Blood lead level
2. Hemoglobin and hematocrit determinations, red cell indices, and examination of
the peripheral blood smear to evaluate red
blood cell morphology
3. Blood urea nitrogen
4. Serum creatinine
5. Routine urinalysis with microscopic examination.
6. A zinc protoporphyrin level
In addition to the above, the physician is
authorized to order any further laboratory
or other tests which he or she deems necessary in accordance with sound medical
practice. The evaluation must also include
pregnancy testing or laboratory evaluation
of male fertility if requested by the employee.
Additional tests which are probably not
warranted on a routine basis but may be appropriate when blood lead and ZPP levels are
equivocal include delta aminolevulinic acid
and coproporphyrin concentrations in the
urine, and dark-field illumination for detection of basophilic stippling in red blood cells.
133
§ 1910.1025
If an anemia is detected further studies including a careful examination of the peripheral smear, reticulocyte count, stool for occult blood, serum iron, total iron binding capacity, bilirubin, and, if appropriate, vitamin B12 and folate may be of value in attempting to identify the cause of the anemia.
If a peripheral neuropathy is suspected,
nerve conduction studies are warranted both
for diagnosis and as a basis to monitor any
therapy.
If renal disease is questioned, a 24 hour
urine collection for creatinine clearance,
protein, and electrolytes may be indicated.
Elevated uric acid levels may result from
lead-induced renal disease and a serum uric
acid level might be performed.
An electrocardiogram and chest x-ray may
be obtained as deemed appropriate.
Sophisticated and highly specialized testing should not be done routinely and where
indicated should be under the direction of a
specialist.
IV. LABORATORY EVALUATION
The blood lead level at present remains the
single most important test to monitor lead
exposure and is the test used in the medical
surveillance program under the lead standard to guide employee medical removal. The
ZPP has several advantages over the blood
lead level. Because of its relatively recent
development and the lack of extensive data
concerning its interpretation, the ZPP currently remains an ancillary test.
This section will discuss the blood lead
level and ZPP in detail and will outline their
relative advantages and disadvantages.
Other blood tests currently available to
evaluate lead exposure will also be reviewed.
The blood lead level is a good index of current or recent lead absorption when there is
no anemia present and when the worker has
not taken any chelating agents. However,
blood lead levels along with urinary lead levels do not necessarily indicate the total body
burden of lead and are not adequate measures of past exposure. One reason for this is
that lead has a high affinity for bone and up
to 90% of the body’s total lead is deposited
there. A very important component of the
total lead body burden is lead in soft tissue
(liver, kidney, and brain). This fraction of
the lead body burden, the biologically active
lead, is not entirely reflected by blood lead
levels since it is a function of the dynamics
of lead absorption, distribution, deposition
in bone and excretion. Following discontinuation of exposure to lead, the excess body
burden is only slowly mobilized from bone
and other relatively stable body stores and
excreted. Consequently, a high blood lead
level may only represent recent heavy exposure to lead without a significant total body
excess and likewise a low blood lead level
does not exclude an elevated total body burden of lead.
Also due to its correlation with recent exposures, the blood lead level may vary considerably over short time intervals.
To minimize laboratory error and erroneous results due to contamination, blood
specimens must be carefully collected after
thorough cleaning of the skin with appropriate methods using lead-free blood containers and analyzed by a reliable laboratory. Under the standard, samples must be
analyzed in laboratories which are approved
by the Center for Disease Control (CDC) or
which have received satisfactory grades in
proficiency testing by the CDC in the previous year. Analysis is to be made using
atomic absorption spectrophotometry, anodic stripping voltammetry or any method
which meets the accuracy requirements set
forth by the standard.
The determination of lead in urine is generally considered a less reliable monitoring
technique than analysis of whole blood primarily due to individual variability in urinary excretion capacity as well as the technical difficulty of obtaining accurate 24 hour
urine collections. In addition, workers with
renal insufficiency, whether due to lead or
some other cause, may have decreased lead
clearance and consequently urine lead levels
may underestimate the true lead burden.
Therefore, urine lead levels should not be
used as a routine test.
The zinc protoporphyrin test, unlike the
blood lead determination, measures an adverse metabolic effect of lead and as such is
a better indicator of lead toxicity than the
level of blood lead itself. The level of ZPP reflects lead absorption over the preceding 3 to
4 months, and therefore is a better indicator
of lead body burden. The ZPP requires more
time than the blood lead to read significantly elevated levels; the return to normal
after discontinuing lead exposure is also
slower. Furthermore, the ZPP test is simpler, faster, and less expensive to perform
and no contamination is possible. Many investigators believe it is the most reliable
means of monitoring chronic lead absorption.
Zinc protoporphyrin results from the inhibition of the enzyme ferrochelatase which
catalyzes the insertion of an iron molecule
into the protoporphyrin molecule, which
then becomes heme. If iron is not inserted
into the molecule then zinc, having a greater
affinity for protoporphyrin, takes the place
of the iron, forming ZPP.
An elevation in the level of circulating
ZPP may occur at blood lead levels as low as
20–30 µ g/100 g in some workers. Once the
blood lead level has reached 40 µ g/100 g there
is more marked rise in the ZPP value from
its normal range of less than 100 µ g/100 ml.
Increases in blood lead levels beyond 40 µ g/
134
100 g are associated with exponential increases in ZPP.
Whereas blood lead levels fluctuate over
short time spans, ZPP levels remain relatively stable. ZPP is measured directly in
red blood cells and is present for the cell’s
entire 120 day life-span. Therefore, the ZPP
level in blood reflects the average ZPP production over the previous 3–4 months and
consequently the average lead exposure during that time interval.
It is recommended that a hematocrit be determined whenever a confirmed ZPP of 50 µ
g/100 ml whole blood is obtained to rule out
a significant underlying anemia. If the ZPP
is in excess of 100 µ g/100 ml and not associated with abnormal elevations in blood lead
levels, the laboratory should be checked to
be sure that blood leads were determined
using atomic absorption spectrophotometry
anodic stripping voltammetry, or any method which meets the accuracy requirements
set forth by the standard by a CDC approved
laboratory which is experienced in lead level
determinations. Repeat periodic blood lead
studies should be obtained in all individuals
with elevated ZPP levels to be certain that
an associated elevated blood lead level has
not been missed due to transient fluctuations in blood leads.
ZPP has a characteristic fluorescence spectrum with a peak at 594 nm which is detectable
with
a
hematofluorimeter.
The
hematofluorimeter is accurate and portable
and can provide on-site, instantaneous results for workers who can be frequently tested via a finger prick.
However, careful attention must be given
to calibration and quality control procedures. Limited data on blood lead—ZPP correlations and the ZPP levels which are associated with the adverse health effects discussed in Section 2 are the major limitations
of the test. Also it is difficult to correlate
ZPP levels with environmental exposure and
there is some variation of response with age
and sex. Nevertheless, the ZPP promises to
be an important diagnostic test for the early
detection of lead toxicity and its value will
increase as more data is collected regarding
its relationship to other manifestations of
lead poisoning.
Levels of delta-aminolevulinic acid (ALA)
in the urine are also used as a measure of
lead exposure. Increasing concentrations of
ALA are believed to result from the inhibition of the enzyme delta-aminolevulinic acid
dehydrase (ALA–D). Although the test is relatively easy to perform, inexpensive, and
rapid, the disadvantages include variability
in results, the necessity to collect a complete 24 hour urine sample which has a specific gravity greater than 1.010, and also the
fact that ALA decomposes in the presence of
light.
The pattern of porphyrin excretion in the
urine can also be helpful in identifying lead
§ 1910.1027
intoxication. With lead poisoning, the urine
concentrations of coproporphyrins I and II,
porphobilinogen and uroporphyrin I rise. The
most important increase, however, is that of
coproporphyrin III; levels may exceed 5,000 µ
g/1 in the urine in lead poisoned individuals,
but its correlation with blood lead levels and
ZPP are not as good as those of ALA. Increases in urinary porphyrins are not diagnostic of lead toxicity and may be seen in
porphyria, some liver diseases, and in patients with high reticulocyte counts.
Summary. The Occupational Safety and
Health Administration’s standard for inorganic lead places significant emphasis on the
medical surveillance of all workers exposed
to levels of inorganic lead above the action
level of 30 µg/m3 TWA. The physician has a
fundamental role in this surveillance program, and in the operation of the medical removal protection program.
Even with adequate worker education on
the adverse health effects of lead and appropriate training in work practices, personal
hygiene and other control measures, the
physician has a primary responsibility for
evaluating potential lead toxicity in the
worker. It is only through a careful and detailed medical and work history, a complete
physical examination and appropriate laboratory testing that an accurate assessment
can be made. Many of the adverse health effects of lead toxicity are either irreversible
or only partially reversible and therefore
early detection of disease is very important.
This document outlines the medical monitoring program as defined by the occupational safety and health standard for inorganic lead. It reviews the adverse health effects of lead poisoning and describes the important elements of the history and physical
examinations as they relate to these adverse
effects. Finally, the appropriate laboratory
testing for evaluating lead exposure and toxicity is presented.
It is hoped that this review and discussion
will give the physician a better understanding of the OSHA standard with the ultimate goal of protecting the health and wellbeing of the worker exposed to lead under his
or her care.
[43 FR 53007, Nov. 14, 1978]
EDITORIAL NOTE: For FEDERAL REGISTER citations affecting § 1910.1025 see the List of
CFR Sections Afffected in the Finding Aids
section of this volume.
§ 1910.1027
Cadmium.
(a) Scope. This standard applies to all
occupational exposures to cadmium
and cadmium compounds, in all forms,
135
§ 1910.1027
and in all industries covered by the Occupational Safety and Health Act, except the construction-related industries, which are covered under 29 CFR
1926.63.
(b) Definitions.
Action level (AL) is defined as an airborne concentration of cadmium of 2.5
micrograms per cubic meter of air (2.5
µg/m3), calculated as an 8-hour timeweighted average (TWA).
authorized by the employer and required by work duties to be present in
regulated areas or any person authorized by the OSH Act or regulations
issued under it to be in regulated areas.
Safety and Health (NIOSH), U.S. Department of Health and Human Services, or designee.
Employee exposure and similar language referring to the air cadmium
level to which an employee is exposed
means the exposure to airborne cadmium that would occur if the employee
were not using respiratory protective
equipment.
Final medical determination is the
written medical opinion of the employee’s health status by the examining
physician under paragraphs (l)(3)-(12) of
this section or, if multiple physician
review under paragraph (l)(13) of this
section or the alternative physician determination under paragraph (l)(14) of
this section is invoked, it is the final,
written medical finding, recommendation or determination that emerges
from that process.
High-efficiency particulate air (HEPA)
filter means a filter capable of trapping
and retaining at least 99.97 percent of
mono-dispersed particles of 0.3 micrometers in diameter.
Regulated area means an area demarcated by the employer where an employee’s exposure to airborne concentrations of cadmium exceeds, or can
reasonably be expected to exceed the
permissible exposure limit (PEL).
This section means this cadmium
standard.
(c) Permissible Exposure Limit (PEL).
The employer shall assure that no employee is exposed to an airborne concentration of cadmium in excess of five
µg/m3), calculated as an eight-hour
time-weighted
average
exposure
(TWA).
(i) Each employer who has a workplace
or work operation covered by this section shall determine if any employee
may be exposed to cadmium at or
above the action level.
(ii) Determinations of employee exposure shall be made from breathing
zone air samples that reflect the monitored employee’s regular, daily 8-hour
TWA exposure to cadmium.
(iii) Eight-hour TWA exposures shall
be determined for each employee on
the basis of one or more personal
breathing zone air samples reflecting
full shift exposure on each shift, for
each job classification, in each work
area. Where several employees perform
the same job tasks, in the same job
classification, on the same shift, in the
same work area, and the length, duration, and level of cadmium exposures
are similar, an employer may sample a
representative fraction of the employees instead of all employees in order to
meet this requirement. In representative sampling, the employer shall sample the employee(s) expected to have
the highest cadmium exposures.
(2) Specific. (i) Initial monitoring. Except as provided for in paragraphs
(d)(2)(ii) and (d)(2)(iii) of this section,
the employer shall monitor employee
exposures and shall base initial determinations on the monitoring results.
(ii) Where the employer has monitored after September 14, 1991, under
conditions that in all important aspects closely resemble those currently
prevailing and where that monitoring
satisfies all other requirements of this
section, including the accuracy and
confidence levels of paragraph (d)(6) of
this section, the employer may rely on
such earlier monitoring results to satisfy the requirements of paragraph
(d)(2)(i) of this section.
(iii) Where the employer has objective data, as defined in paragraph (n)(2)
of this section, demonstrating that employee exposure to cadmium will not
136
exceed the action level under the expected conditions of processing, use, or
handling, the employer may rely upon
such data instead of implementing initial monitoring.
(3) Monitoring Frequency (periodic
monitoring). (i) If the initial monitoring
or periodic monitoring reveals employee exposures to be at or above the
action level, the employer shall monitor at a frequency and pattern needed
to represent the levels of exposure of
employees and where exposures are
above the PEL to assure the adequacy
of respiratory selection and the effectiveness of engineering and work practice controls. However, such exposure
monitoring shall be performed at least
every six months. The employer, at a
minimum, shall continue these semiannual measurements unless and until
the conditions set out in paragraph
(d)(3)(ii) of this section are met.
(ii) If the initial monitoring or the
periodic monitoring indicates that employee exposures are below the action
level and that result is confirmed by
the results of another monitoring
taken at least seven days later, the employer may discontinue the monitoring
for those employees whose exposures
are represented by such monitoring.
(4) Additional Monitoring. The employer also shall institute the exposure
(d)(2)(i) and (d)(3) of this section whenever there has been a change in the raw
materials, equipment, personnel, work
practices, or finished products that
may result in additional employees
being exposed to cadmium at or above
the action level or in employees already exposed to cadmium at or above
the action level being exposed above
the PEL, or whenever the employer has
any reason to suspect that any other
change might result in such further exposure.
(5) Employee Notification of Monitoring
Results. (i) Within 15 working days
after the receipt of the results of any
monitoring performed under this section, the employer shall notify each affected employee individually in writing
of the results. In addition, within the
same time period the employer shall
post the results of the exposure monitoring in an appropriate location that
is accessible to all affected employees.
§ 1910.1027
(ii) Wherever monitoring results indicate that employee exposure exceeds
the PEL, the employer shall include in
the written notice a statement that
the PEL has been exceeded and a description of the corrective action being
taken by the employer to reduce employee exposure to or below the PEL.
(6) Accuracy of measurement. The employer shall use a method of monitoring and analysis that has an accuracy of not less than plus or minus 25
percent (±25%), with a confidence level
of 95 percent, for airborne concentrations of cadmium at or above the action level, the permissible exposure
limit (PEL), and the separate engineering control air limit (SECAL).
(e) Regulated areas—(1) Establishment.
The employer shall establish a regulated area wherever an employee’s exposure to airborne concentrations of
cadmium is, or can reasonably be expected to be in excess of the permissible exposure limit (PEL).
be demarcated from the rest of the
workplace in any manner that adequately establishes and alerts employees of the boundaries of the regulated
area.
shall be limited to authorized persons.
(4) Provision of respirators. Each person entering a regulated area shall be
supplied with and required to use a respirator, selected in accordance with
paragraph (g)(2) of this section.
shall assure that employees do not eat,
drink, smoke, chew tobacco or gum, or
apply cosmetics in regulated areas,
carry the products associated with
these activities into regulated areas, or
store such products in those areas.
(f) Methods of compliance—(1) Compliance hierarchy. (i) Except as specified in
paragraphs (f)(1) (ii), (iii) and (iv) of
this section the employer shall implement engineering and work practice
controls to reduce and maintain employee exposure to cadmium at or
below the PEL, except to the extent
that the employer can demonstrate
that such controls are not feasible.
(ii) Except as specified in paragraphs
(f)(1) (iii) and (iv) of this section, in industries where a separate engineering
control air limit (SECAL) has been
137
§ 1910.1027
specified for particular processes (See
Table 1 in this paragraph (f)(1)(ii)), the
employer shall implement engineering
and work practice controls to reduce
and maintain employee exposure at or
below the SECAL, except to the extent
that the employer can demonstrate
that such controls are not feasible.
TABLE I—SEPARATE ENGINEERING CONTROL AIRBORNE LIMITS (SECALS) FOR PROCESSES IN
SELECTED INDUSTRIES
Industry
Process
Nickel cadmium battery .......................
Plate making, plate preparation ......................................................................
All other processes ..........................................................................................
Cadmium refining, casting, melting, oxide production, sinter plant ................
Calcine, crushing, milling, blending .................................................................
All other processes ..........................................................................................
Cadmium oxide charging, crushing, drying, blending .....................................
Sinter plant, blast furnace, baghouse, yard area ............................................
Mechanical plating ...........................................................................................
Zinc/Cadmium refining* .......................
Pigment manufacture ..........................
Stabilizers* ..........................................
Lead smelting* ....................................
Plating* ................................................
SECAL
(µg/m3)
50
15
50
50
15
50
50
15
*Processes in these industries that are not specified in this table must achieve the PEL using engineering controls and work
practices as required in f(1)(i).
(iii) The requirement to implement
engineering and work practice controls
to achieve the PEL or, where applicable, the SECAL does not apply where
the employer demonstrates the following:
(A) The employee is only intermittently exposed; and
(B) The employee is not exposed
above the PEL on 30 or more days per
year (12 consecutive months).
(iv) Wherever engineering and work
practice controls are required and are
not sufficient to reduce employee exposure to or below the PEL or, where applicable, the SECAL, the employer
nonetheless shall implement such controls to reduce exposures to the lowest
levels achievable. The employer shall
supplement such controls with respiratory protection that complies with
this section and the PEL.
(v) The employer shall not use employee rotation as a method of compliance.
(2) Compliance program. (i) Where the
PEL is exceeded, the employer shall establish and implement a written compliance program to reduce employee
exposure to or below the PEL by means
of engineering and work practice controls, as required by paragraph (f)(1) of
this section. To the extent that engineering and work practice controls
cannot reduce exposures to or below
the PEL, the employer shall include in
the written compliance program the
use of appropriate respiratory protec-
tion to achieve compliance with the
PEL.
(ii) Written compliance programs
shall include at least the following:
which cadmium is emitted; e.g., machinery used, material processed, controls in place, crew size, employee job
responsibilities, operating procedures,
and maintenance practices;
(B) A description of the specific
means that will be employed to achieve
compliance,
including
engineering
plans and studies used to determine
methods selected for controlling exposure to cadmium, as well as, where necessary, the use of appropriate respiratory protection to achieve the
PEL;
(C) A report of the technology considered in meeting the PEL;
(D) Air monitoring data that document the sources of cadmium emissions;
(E) A detailed schedule for implementation of the program, including documentation such as copies of purchase
orders for equipment, construction
contracts, etc.;
(F) A work practice program that includes items required under paragraphs
(h), (i), and (j) of this section;
(G) A written plan for emergency situations, as specified in paragraph (h) of
this section; and
(H) Other relevant information.
(iii) The written compliance programs shall be reviewed and updated at
138
least annually, or more often if necessary, to reflect significant changes in
the employer’s compliance status.
(iv) Written compliance programs
shall be provided upon request for examination and copying to affected employees, designated employee representatives as well as to the Assistant
Secretary, and the Director.
(3) Mechanical ventilation. (i) When
ventilation is used to control exposure,
measurements that demonstrate the effectiveness of the system in controlling
exposure, such as capture velocity,
duct velocity, or static pressure shall
be made as necessary to maintain its
effectiveness.
(ii) Measurements of the system’s effectiveness in controlling exposure
shall be made as necessary within five
working days of any change in production, process, or control that might result in a significant increase in employee exposure to cadmium.
(iii) Recirculation of air. If air from
exhaust ventilation is recirculated into
the workplace, the system shall have a
high efficiency filter and be monitored
to assure effectiveness.
(iv) Procedures shall be developed
and implemented to minimize employee exposure to cadmium when
maintenance of ventilation systems
and changing of filters is being conducted.
(i) Periods necessary to install or implement feasible engineering and workpractice controls when employee exposure levels exceed the PEL.
(ii) Maintenance and repair activities, and brief or intermittent operations, for which employee exposures
exceed the PEL and engineering and
§ 1910.1027
work-practice controls are not feasible
or are not required.
(iii) Activities in regulated areas
specified in paragraph (e) of this section.
(iv) Work operations for which the
employer has implemented all feasible
engineering and work-practice controls
and such controls are not sufficient to
reduce employee exposures to or below
the PEL.
(v) Work operations for which an employee is exposed to cadmium at or
above the action level, and the employee requests a respirator.
(vi) Work operations for which an
employee is exposed to cadmium above
the PEL and engineering controls are
not required by paragraph (f)(1)(ii) of
this section.
(vii) Emergencies.
(ii) No employees must use a respirator if, based on their most recent
medical examination, the examining
physician determines that they will be
unable to continue to function normally while using a respirator. If the
physician determines that the employee must be limited in, or removed
from, their current job because of their
inability to use a respirator, the limitation or removal must be in accordance with paragraphs (l) (11) and (12) of
this section.
(iii) If an employee has breathing difficulty during fit testing or respirator
use, the employer must provide the employee with a medical examination in
accordance with paragraph (l)(6)(ii) of
this section to determine if the employee can use a respirator while performing the required duties.
(3) Respirator selection. (i) The employer must select the appropriate respirator from Table 2 of this section.
TABLE 2—RESPIRATORY PROTECTION FOR CADMIUM
Airborne concentration or condition of use a
Required respirator type b
10 X or less .................................................
25 X or less .................................................
A half mask, air-purifying equipped with a HEPA c filter.d
A powered air-purifying respirator (‘‘PAPR’’) with a loose-fitting hood or helmet
equipped with a HEPA filter, or a supplied-air respirator with a loose-fitting hood
or helmet facepiece operated in the continuous flow mode.
139
§ 1910.1027
TABLE 2—RESPIRATORY PROTECTION FOR CADMIUM—Continued
Airborne concentration or condition of use a
Required respirator type b
50 X or less .................................................
A full facepiece air-purifying respirator equipped with a HEPA filter, or a powered
air-purifying respirator with a tight-fitting half mask equipped with a HEPA filter,
or a supplied-air respirator with a tight-fitting half mask operated in the continuous flow mode.
A powered air-purifying respirator with a tight fitting full facepiece equipped with a
HEPA filter, or a supplied-air respirator with a tight-fitting full facepiece operated
in the continuous flow mode.
A supplied air respirator with half mask or full facepiece operated in the pressure
demand or other positive pressure mode.
A self-contained breathing apparatus with a full facepiece operated in the pressure
demand or other positive pressure mode, or a supplied-air respirator with a full
facepiece operated in the pressure demand or other positive pressure mode and
equipped with an auxiliary escape type self-contained breathing apparatus operated in the pressure demand mode.
A self-contained breathing apparatus with full facepiece operated in the pressure
demand or other positive pressure mode.
250 X or less ...............................................
1000 X or less .............................................
>1000 X or unknown concentrations ..........
Fire fighting .................................................
a Concentrations expressed as multiple of the PEL.
b Respirators assigned for higher environmental concentrations may be used at lower exposure levels. Quantitative fit testing is
required for all tight-fitting air purifying respirators where airborne concentration of cadmium exceeds 10 times the TWA PEL (10
X 5 ug/m(3) = 50 ug/m(3)). A full facepiece respirator is required when eye irritation is experienced.
c HEPA means High-efficiency Particulate Air.
d Fit testing, qualitative or quantitative, is required.
SOURCE: Respiratory Decision Logic, NIOSH, 1987.
(ii) The employer must provide an
employee with a powered air-purifying
respirator instead of a negative-pressure respirator when an employee who
is entitled to a respirator chooses to
use this type of respirator and such a
respirator provides adequate protection
to the employee.
(h) Emergency situations. The employer shall develop and implement a
written plan for dealing with emergency situations involving substantial
releases of airborne cadmium. The plan
shall include provisions for the use of
appropriate respirators and personal
protective equipment. In addition, employees not essential to correcting the
emergency situation shall be restricted
from the area and normal operations
halted in that area until the emergency is abated.
(i) Protective work clothing and equipment—(1) Provision and use. If an employee is exposed to airborne cadmium
above the PEL or where skin or eye irritation is associated with cadmium
exposure at any level, the employer
shall provide at no cost to the employee, and assure that the employee
uses, appropriate protective work
clothing and equipment that prevents
contamination of the employee and the
employee’s garments. Protective work
clothing and equipment includes, but is
not limited to:
work clothing;
(ii) Gloves, head coverings, and boots
or foot coverings; and
other appropriate protective equipment that complies with 29 CFR
1910.133.
(2) Removal and storage. (i) The employer shall assure that employees remove all protective clothing and equipment contaminated with cadmium at
the completion of the work shift and do
so only in change rooms provided in accordance with paragraph (j)(1) of this
section.
employee
takes
cadmium-contaminated protective clothing or equipment
from the workplace, except for employees authorized to do so for purposes of
laundering, cleaning, maintaining, or
disposing of cadmium contaminated
protective clothing and equipment at
an appropriate location or facility
away from the workplace.
contaminated protective clothing and
equipment, when removed for laundering, cleaning, maintenance, or disposal, is placed and stored in sealed,
impermeable bags or other closed, impermeable containers that are designed
to prevent dispersion of cadmium dust.
bags or containers of contaminated
140
protective clothing and equipment that
are to be taken out of the change
rooms or the workplace for laundering,
cleaning, maintenance or disposal shall
bear labels in accordance with paragraph (m)(3) of this section.
(3) Cleaning, replacement, and disposal.
(i) The employer shall provide the protective clothing and equipment required by paragraph (i)(1) of this section in a clean and dry condition as
often as necessary to maintain its effectiveness, but in any event at least
weekly. The employer is responsible
for cleaning and laundering the protective clothing and equipment required
by this paragraph to maintain its effectiveness and is also responsible for disposing of such clothing and equipment.
(ii) The employer also is responsible
for repairing or replacing required protective clothing and equipment as
needed to maintain its effectiveness.
When rips or tears are detected while
an employee is working they shall be
immediately mended, or the worksuit
shall be immediately replaced.
(iii) The employer shall prohibit the
removal of cadmium from protective
clothing and equipment by blowing,
shaking, or any other means that disperses cadmium into the air.
any laundering of contaminated clothing or cleaning of contaminated equipment in the workplace is done in a
manner that prevents the release of
airborne cadmium in excess of the permissible exposure limit prescribed in
paragraph (c) of this section.
(v) The employer shall inform any
person who launders or cleans protective clothing or equipment contaminated with cadmium of the potentially
harmful effects of exposure to cadmium and that the clothing and equipment should be laundered or cleaned in
a manner to effectively prevent the release of airborne cadmium in excess of
the PEL.
(j) Hygiene areas and practices—(1)
General. For employees whose airborne
exposure to cadmium is above the PEL,
the employer shall provide clean
change rooms, handwashing facilities,
showers, and lunchroom facilities that
comply with 29 CFR 1910.141.
(2) Change rooms. The employer shall
assure that change rooms are equipped
§ 1910.1027
with separate storage facilities for
street clothes and for protective clothing and equipment, which are designed
to prevent dispersion of cadmium and
contamination of the employee’s street
clothes.
(3) Showers and handwashing facilities.
(i) The employer shall assure that employees who are exposed to cadmium
above the PEL shower during the end
of the work shift.
employees whose airborne exposure to
cadmium is above the PEL wash their
hands and faces prior to eating, drinking, smoking, chewing tobacco or gum,
or applying cosmetics.
(4) Lunchroom facilities. (i) The employer shall assure that the lunchroom
facilities are readily accessible to employees, that tables for eating are
maintained free of cadmium, and that
no employee in a lunchroom facility is
exposed at any time to cadmium at or
above a concentration of 2.5 µg/m3.
or equipment unless surface cadmium
has been removed from the clothing
and equipment by HEPA vacuuming or
some other method that removes cadmium dust without dispersing it.
(k) Housekeeping. (1) All surfaces
shall be maintained as free as practicable of accumulations of cadmium.
(2) All spills and sudden releases of
material containing cadmium shall be
cleaned up as soon as possible.
(3) Surfaces contaminated with cadmium shall, wherever possible, be
cleaned by vacuuming or other methods that minimize the likelihood of
cadmium becoming airborne.
(4) HEPA-filtered vacuuming equipment or equally effective filtration
methods shall be used for vacuuming.
The equipment shall be used and
emptied in a manner that minimizes
the reentry of cadmium into the workplace.
(5) Shoveling, dry or wet sweeping,
and brushing may be used only where
vacuuming or other methods that minimize the likelihood of cadmium becoming airborne have been tried and
found not to be effective.
(6) Compressed air shall not be used
to remove cadmium from any surface
141
§ 1910.1027
unless the compressed air is used in
conjunction with a ventilation system
designed to capture the dust cloud created by the compressed air.
(7) Waste, scrap, debris, bags, containers, personal protective equipment,
and clothing contaminated with cadmium and consigned for disposal shall
be collected and disposed of in sealed
impermeable bags or other closed, impermeable containers. These bags and
containers shall be labeled in accordance with paragraph (m)(2) of this section.
(l) Medical surveillance—(1) General—
(i) Scope. (A) Currently exposed—The
employer shall institute a medical surveillance program for all employees
who are or may be exposed to cadmium
at or above the action level unless the
employer demonstrates that the employee is not, and will not be, exposed
at or above the action level on 30 or
more days per year (twelve consecutive
months); and,
(B) Previously exposed—The employer shall also institute a medical
surveillance program for all employees
who prior to the effective date of this
section might previously have been exposed to cadmium at or above the action level by the employer, unless the
employer demonstrates that the employee did not prior to the effective
date of this section work for the employer in jobs with exposure to cadmium for an aggregated total of more
than 60 months.
(ii) To determine an employee’s fitness for using a respirator, the employer shall provide the limited medical examination specified in paragraph
(l)(6) of this section.
all medical examinations and procedures required by this standard are performed by or under the supervision of a
licensed physician, who has read and is
familiar with the health effects section
of appendix A to this section, the regulatory text of this section, the protocol
for sample handling and laboratory selection in appendix F to this section,
and the questionnaire of appendix D to
this section. These examinations and
procedures shall be provided without
cost to the employee and at a time and
place that is reasonable and convenient
to employees.
the collecting and handling of biological samples of cadmium in urine (CdU),
cadmium in blood (CdB), and beta-2
microglobulin in urine (β2-M) taken
from employees under this section is
done in a manner that assures their reliability and that analysis of biological
samples of cadmium in urine (CdU),
cadmium in blood (CdB), and beta-2
microglobulin in urine (β2-M) taken
from employees under this section is
performed in laboratories with demonstrated proficiency for that particular analyte. (See appendix F to this
section.)
(2) Initial examination. (i) The employer
shall
provide
an
initial
(preplacement) examination to all employees covered by the medical surveillance program required in paragraph
(l)(1)(i) of this section. The examination shall be provided to those employees within 30 days after initial assignment to a job with exposure to cadmium or no later than 90 days after the
effective date of this section, whichever date is later.
(ii) The initial (preplacement) medical examination shall include:
(A) A detailed medical and work history, with emphasis on: Past, present,
and anticipated future exposure to cadmium; any history of renal, cardiovascular, respiratory, hematopoietic,
reproductive, and/or musculo-skeletal
system dysfunction; current usage of
medication with potential nephrotoxic
side-effects; and smoking history and
current status; and
(B) Biological monitoring that includes the following tests:
(1) Cadmium in urine (CdU), standardized to grams of creatinine (g/Cr);
(2) Beta-2 microglobulin in urine (β2M), standardized to grams of creatinine
(g/Cr), with pH specified, as described
in appendix F to this section; and
(3) Cadmium in blood (CdB), standardized to liters of whole blood (lwb).
(iii) Recent Examination: An initial
examination is not required to be provided if adequate records show that the
employee has been examined in accordance with the requirements of paragraph (l)(2)(ii) of this section within
the past 12 months. In that case, such
records shall be maintained as part of
the employee’s medical record and the
142
prior exam shall be treated as if it were
an initial examination for the purposes
of paragraphs (l)(3) and (4) of this section.
(3) Actions triggered by initial biological
monitoring: (i) If the results of the initial biological monitoring tests show
the employee’s CdU level to be at or
below 3 µg/g Cr, β2-M level to be at or
below 300 µg/g Cr and CdB level to be at
or below 5 µg/lwb, then:
(A) For currently exposed employees,
who are subject to medical surveillance
under paragraph (l)(1)(i)(A) of this section, the employer shall provide the
minimum level of periodic medical surveillance in accordance with the requirements in paragraph (l)(4)(i) of this
section; and
(B) For previously exposed employees, who are subject to medical surveillance under paragraph (l)(1)(i)(B) of
this section, the employer shall provide
biological monitoring for CdU, β2-M,
and CdB one year after the initial biological monitoring and then the employer shall comply with the requirements of paragraph (l)(4)(v) of this section.
(ii) For all employees who are subject
to medical surveillance under paragraph (l)(1)(i) of this section, if the results of the initial biological monitoring tests show the level of CdU to
exceed 3 µg/g Cr, the level of β2-M to exceed 300 µg/g Cr, or the level of CdB to
exceed 5 µg/lwb, the employer shall:
(A) Within two weeks after receipt of
biological monitoring results, reassess
the employee’s occupational exposure
to cadmium as follows:
(1) Reassess the employee’s work
practices and personal hygiene;
(2) Reevaluate the employee’s respirator use, if any, and the respirator
program;
(3) Review the hygiene facilities;
(4) Reevaluate the maintenance and
effectiveness of the relevant engineering controls;
(5) Assess the employee’s smoking
history and status;
(B) Within 30 days after the exposure
reassessment, specified in paragraph
(l)(3)(ii)(A) of this section, take reasonable steps to correct any deficiencies
found in the reassessment that may be
responsible for the employee’s excess
exposure to cadmium; and,
§ 1910.1027
(C) Within 90 days after receipt of biological monitoring results, provide a
full medical examination to the employee in accordance with the requirements of paragraph (l)(4)(ii) of this section. After completing the medical examination, the examining physician
shall determine in a written medical
opinion whether to medically remove
the employee. If the physician determines that medical removal is not necessary, then until the employee’s CdU
level falls to or below 3 µg/g Cr, β2-M
level falls to or below 300 µg/g Cr and
CdB level falls to or below 5 µg/lwb, the
employer shall:
(1) Provide biological monitoring in
accordance with paragraph (l)(2)(ii)(B)
of this section on a semiannual basis;
and
(2) Provide annual medical examinations in accordance with paragraph
(l)(4)(ii) of this section.
(iii) For all employees who are subject to medical surveillance under
paragraph (l)(1)(i) of this section, if the
results of the initial biological monitoring tests show the level of CdU to be
in excess of 15 µg/g Cr, or the level of
CdB to be in excess of 15 µg/lwb, or the
level of β2-M to be in excess of 1,500 µg/
g Cr, the employer shall comply with
the
requirements
of
paragraphs
(l)(3)(ii)(A)–(B) of this section. Within
90 days after receipt of biological monitoring results, the employer shall provide a full medical examination to the
employee in accordance with the requirements of paragraph (l)(4)(ii) of
this section. After completing the medical examination, the examining physician shall determine in a written medical opinion whether to medically remove the employee. However, if the
initial biological monitoring results
and the biological monitoring results
obtained during the medical examination both show that: CdU exceeds 15 µg/
g Cr; or CdB exceeds 15 µg/lwb; or β2-M
exceeds 1500 µg/g Cr, and in addition
CdU exceeds 3 µg/g Cr or CdB exceeds 5
µg/liter of whole blood, then the physician shall medically remove the employee from exposure to cadmium at or
above the action level. If the second set
of biological monitoring results obtained during the medical examination
does not show that a mandatory removal trigger level has been exceeded,
143
§ 1910.1027
then the employee is not required to be
removed by the mandatory provisions
of this paragraph. If the employee is
not required to be removed by the mandatory provisions of this paragraph or
by the physician’s determination, then
until the employee’s CdU level falls to
or below 3 µg/g Cr, β2-M level falls to or
below 300 µg/g Cr and CdB level falls to
or below 5 µg/lwb, the employer shall:
(A) Periodically reassess the employee’s occupational exposure to cadmium;
(B) Provide biological monitoring in
accordance with paragraph (l)(2)(ii)(B)
of this section on a quarterly basis; and
(C) Provide semiannual medical examinations in accordance with paragraph (l)(4)(ii) of this section.
(iv) For all employees to whom medical surveillance is provided, beginning
on January 1, 1999, and in lieu of paragraphs (l)(3)(i)–(iii) of this section:
(A) If the results of the initial biological monitoring tests show the employee’s CdU level to be at or below 3
µg/g Cr, β2-M level to be at or below 300
µg/g Cr and CdB level to be at or below
5 µg/lwb, then for currently exposed
employees, the employer shall comply
with the requirements of paragraph
(l)(3)(i)(A) of this section, and for previously exposed employees, the employer shall comply with the requirements of paragraph (l)(3)(i)(B) of this
section;
(B) If the results of the initial biological monitoring tests show the level
of CdU to exceed 3 µg/g Cr, the level of
β2-M to exceed 300 µg/g Cr, or the level
of CdB to exceed 5 µg/lwb, the employer
shall comply with the requirements of
paragraphs (l)(3)(ii)(A)–(C) of this section; and,
(C) If the results of the initial biological monitoring tests show the level
of CdU to be in excess of 7 µg/g Cr, or
the level of CdB to be in excess of 10 µg/
lwb, or the level of β2-M to be in excess
of 750 µg/g Cr, the employer shall: Comply with the requirements of paragraphs (l)(3)(ii)(A)–(B) of this section;
and, within 90 days after receipt of biological monitoring results, provide a
full medical examination to the employee in accordance with the requirements of paragraph (l)(4)(ii) of this section. After completing the medical examination, the examining physician
shall determine in a written medical
opinion whether to medically remove
the employee. However, if the initial
biological monitoring results and the
biological monitoring results obtained
during the medical examination both
show that: CdU exceeds 7 µg/g Cr; or
CdB exceeds 10 µg/lwb; or β2-M exceeds
750 µg/g Cr, and in addition CdU exceeds
3 µg/g Cr or CdB exceeds 5 µg/liter of
whole blood, then the physician shall
medically remove the employee from
exposure to cadmium at or above the
action level. If the second set of biological monitoring results obtained
during the medical examination does
not show that a mandatory removal
trigger level has been exceeded, then
the employee is not required to be removed by the mandatory provisions of
this paragraph. If the employee is not
required to be removed by the mandatory provisions of this paragraph or by
the physician’s determination, then
until the employee’s CdU level falls to
or below 3 µg/g Cr, β2-M level falls to or
below 300 µg/g Cr and CdB level falls to
or below 5 µg/lwb, the employer shall:
periodically reassess the employee’s
occupational exposure to cadmium;
provide biological monitoring in accordance with paragraph (l)(2)(ii)(B) of
this section on a quarterly basis; and
provide semiannual medical examinations in accordance with paragraph
(l)(4)(ii) of this section.
(4) Periodic medical surveillance. (i)
For each employee who is covered
under paragraph (l)(1)(i)(A) of this section, the employer shall provide at
least the minimum level of periodic
medical surveillance, which consists of
periodic medical examinations and
periodic biological monitoring. A periodic medical examination shall be provided within one year after the initial
examination required by paragraph
(l)(2) of this section and thereafter at
least biennially. Biological sampling
shall be provided at least annually, either as part of a periodic medical examination or separately as periodic biological monitoring.
(ii) The periodic medical examination
shall include:
(A) A detailed medical and work history, or update thereof, with emphasis
on: Past, present and anticipated future exposure to cadmium; smoking
144
history and current status; reproductive history; current use of medications with potential nephrotoxic sideeffects; any history of renal, cardiovascular, respiratory, hematopoietic,
and/or musculo-skeletal system dysfunction; and as part of the medical
and work history, for employees who
wear respirators, questions 3–11 and 25–
32 in Appendix D to this section;
(B) A complete physical examination
with emphasis on: Blood pressure, the
respiratory system, and the urinary
system;
(C) A 14 inch by 17 inch, or a reasonably standard sized posterior-anterior
chest X-ray (after the initial X-ray, the
frequency of chest X-rays is to be determined by the examining physician);
(D) Pulmonary function tests, including forced vital capacity (FVC) and
forced expiratory volume at 1 second
(FEV1);
(E) Biological monitoring, as required in paragraph (l)(2)(ii)(B) of this
section;
(F) Blood analysis, in addition to the
analysis required under paragraph
(l)(2)(ii)(B) of this section, including
blood urea nitrogen, complete blood
count, and serum creatinine;
(G) Urinalysis, in addition to the
analysis required under paragraph
(l)(2)(ii)(B) of this section, including
the determination of albumin, glucose,
and total and low molecular weight
proteins;
(H) For males over 40 years old, prostate palpation, or other at least as effective diagnostic test(s); and
(I) Any additional tests deemed appropriate by the examining physician.
(iii) Periodic biological monitoring
shall be provided in accordance with
paragraph (l)(2)(ii)(B) of this section.
(iv) If the results of periodic biological monitoring or the results of biological monitoring performed as part of
the periodic medical examination show
the level of the employee’s CdU, β2-M,
or CdB to be in excess of the levels
specified in paragraphs (l)(3)(ii) or (iii);
or, beginning on January 1, 1999, in excess of the levels specified in paragraphs (l)(3)(ii) or (iv) of this section,
the employer shall take the appropriate actions specified in paragraphs
(l)(3)(ii)–(iv) of this section.
§ 1910.1027
(v) For previously exposed employees
under paragraph (l)(1)(i)(B) of this section:
(A) If the employee’s levels of CdU
did not exceed 3 µg/g Cr, CdB did not
exceed 5 µg/lwb, and β2-M did not exceed 300 µg/g Cr in the initial biological
monitoring tests, and if the results of
the followup biological monitoring required by paragraph (l)(3)(i)(B) of this
section one year after the initial examination confirm the previous results,
the employer may discontinue all periodic medical surveillance for that employee.
(B) If the initial biological monitoring results for CdU, CdB, or β2-M
were in excess of the levels specified in
paragraph (l)(3)(i) of this section, but
subsequent biological monitoring results required by paragraph (l)(3)(ii)–
(iv) of this section show that the employee’s CdU levels no longer exceed 3
µg/g Cr, CdB levels no longer exceed 5
µg/lwb, and β2-M levels no longer exceed 300 µg/g Cr, the employer shall
provide biological monitoring for CdU,
CdB, and β2-M one year after these
most recent biological monitoring results. If the results of the followup biological monitoring, specified in this
paragraph, confirm the previous results, the employer may discontinue
all periodic medical surveillance for
that employee.
(C) However, if the results of the follow-up tests specified in paragraph
(l)(4)(v)(A) or (B) of this section indicate that the level of the employee’s
CdU, β2–M, or CdB exceeds these same
levels, the employer is required to provide annual medical examinations in
accordance with the provisions of paragraph (l)(4)(ii) of this section until the
results of biological monitoring are
consistently below these levels or the
examining physician determines in a
written medical opinion that further
medical surveillance is not required to
protect the employee’s health.
(vi) A routine, biennial medical examination is not required to be provided in accordance with paragraphs
(l)(3)(i) and (l)(4) of this section if adequate medical records show that the
employee has been examined in accordance with the requirements of paragraph (l)(4)(ii) of this section within
the past 12 months. In that case, such
145
§ 1910.1027
records shall be maintained by the employer as part of the employee’s medical record, and the next routine, periodic medical examination shall be
made available to the employee within
two years of the previous examination.
(5) Actions triggered by medical examinations. (i) If the results of a medical
examination carried out in accordance
with this section indicate any laboratory or clinical finding consistent with
cadmium toxicity that does not require
employer action under paragraph (l)(2),
(3) or (4) of this section, the employer,
within 30 days, shall reassess the employee’s occupational exposure to cadmium and take the following corrective action until the physician determines they are no longer necessary:
(A) Periodically reassess: The employee’s work practices and personal
hygiene; the employee’s respirator use,
if any; the employee’s smoking history
and status; the respiratory protection
program; the hygiene facilities; and the
maintenance and effectiveness of the
relevant engineering controls;
(B) Within 30 days after the reassessment, take all reasonable steps to correct the deficiencies found in the reassessment that may be responsible for
the employee’s excess exposure to cadmium;
(C) Provide semiannual medical reexaminations to evaluate the abnormal
clinical sign(s) of cadmium toxicity
until the results are normal or the employee is medically removed; and
(D) Where the results of tests for
total proteins in urine are abnormal,
provide a more detailed medical evaluation of the toxic effects of cadmium
on the employee’s renal system.
(6) Examination for respirator use. (i)
To determine an employee’s fitness for
respirator use, the employer shall provide a medical examination that includes the elements specified in paragraph (l)(6)(i)(A)–(D) of this section.
This examination shall be provided
prior to the employee’s being assigned
to a job that requires the use of a respirator or no later than 90 days after
this section goes into effect, whichever
date is later, to any employee without
a medical examination within the preceding 12 months that satisfies the requirements of this paragraph.
(A) A detailed medical and work history, or update thereof, with emphasis
on: Past exposure to cadmium; smoking history and current status; any history of renal, cardiovascular, respiratory, hematopoietic, and/or musculoskeletal system dysfunction; a description of the job for which the respirator is required; and questions 3–11
and 25–32 in appendix D to this section;
(B) A blood pressure test;
(C) Biological monitoring of the employee’s levels of CdU, CdB and β2-M in
accordance with the requirements of
paragraph (l)(2)(ii)(B) of this section,
unless such results already have been
obtained within the previous 12
months; and
(D) Any other test or procedure that
the examining physician deems appropriate.
(ii) After reviewing all the information obtained from the medical examination required in paragraph (l)(6)(i)
of this section, the physician shall determine whether the employee is fit to
wear a respirator.
(iii) Whenever an employee has exhibited difficulty in breathing during a
respirator fit test or during use of a
respirator, the employer, as soon as
possible, shall provide the employee
with a periodic medical examination in
accordance with paragraph (l)(4)(ii) of
this section to determine the employee’s fitness to wear a respirator.
(iv) Where the results of the examination required under paragraph
(l)(6)(i), (ii), or (iii) of this section are
abnormal, medical limitation or prohibition of respirator use shall be considered. If the employee is allowed to wear
a respirator, the employee’s ability to
continue to do so shall be periodically
evaluated by a physician.
(7) Emergency examinations. (i) In addition to the medical surveillance required in paragraphs (l)(2)–(6) of this
section, the employer shall provide a
medical examination as soon as possible to any employee who may have
been acutely exposed to cadmium because of an emergency.
(ii) The examination shall include
the requirements of paragraph (l)(4)(ii)
of this section, with emphasis on the
respiratory system, other organ systems considered appropriate by the examining physician, and symptoms of
146
acute overexposure, as identified in
paragraphs II (B)(1)–(2) and IV of appendix A to this section.
(8) Termination of employment examination. (i) At termination of employment, the employer shall provide a
medical examination in accordance
with paragraph (l)(4)(ii) of this section,
including a chest X-ray, to any employee to whom at any prior time the
employer was required to provide medical surveillance under paragraphs
(l)(1)(i) or (l)(7) of this section. However, if the last examination satisfied
the requirements of paragraph (l)(4)(ii)
of this section and was less than six
months prior to the date of termination, no further examination is required unless otherwise specified in
paragraphs (l)(3) or (l)(5) of this section;
(ii) However, for employees covered
by paragraph (l)(1)(i)(B) of this section,
if the employer has discontinued all
periodic medical surveillance under
paragraph (l)(4)(v) of this section, no
termination of employment medical
examination is required.
(i) A copy of this standard and appendices;
(ii) A description of the affected employee’s former, current, and anticipated duties as they relate to the employee’s occupational exposure to cadmium;
(iii) The employee’s former, current,
and anticipated future levels of occupational exposure to cadmium;
protective equipment, including respirators, used or to be used by the employee, including when and for how
long the employee has used that equipment; and
(v) relevant results of previous biological monitoring and medical examinations.
(10) Physician’s written medical opinion. (i) The employer shall promptly
obtain a written, signed medical opinion from the examining physician for
each medical examination performed
on each employee. This written opinion
shall contain:
§ 1910.1027
(A) The physician’s diagnosis for the
employee;
(B) The physician’s opinion as to
medical condition(s) that would place
the employee at increased risk of material impairment to health from further exposure to cadmium, including
any indications of potential cadmium
toxicity;
(C) The results of any biological or
other testing or related evaluations
that directly assess the employee’s absorption of cadmium;
(D) Any recommended removal from,
or limitation on the activities or duties
of the employee or on the employee’s
use of personal protective equipment,
such as respirators;
(E) A statement that the physician
has clearly and carefully explained to
the employee the results of the medical
examination, including all biological
monitoring results and any medical
conditions related to cadmium exposure that require further evaluation or
treatment, and any limitation on the
employee’s diet or use of medications.
(ii) The employer promptly shall obtain a copy of the results of any biological monitoring provided by an employer to an employee independently of
a medical examination under paragraphs (l)(2) and (l)(4) of this section,
and, in lieu of a written medical opinion, an explanation sheet explaining
those results.
(iii) The employer shall instruct the
physician not to reveal orally or in the
written medical opinion given to the
employer specific findings or diagnoses
unrelated to occupational exposure to
cadmium.
(11)
Medical
Removal
Protection
(MRP)—(i) General. (A) The employer
shall temporarily remove an employee
from work where there is excess exposure to cadmium on each occasion that
medical removal is required under
paragraph (l)(3), (l)(4), or (l)(6) of this
section and on each occasion that a
physician determines in a written medical opinion that the employee should
be removed from such exposure. The
physician’s determination may be
based on biological monitoring results,
inability to wear a respirator, evidence
of illness, other signs or symptoms of
147
§ 1910.1027
cadmium-related dysfunction or disease, or any other reason deemed medically sufficient by the physician.
(B) The employer shall medically remove an employee in accordance with
paragraph (l)(11) of this section regardless of whether at the time of removal
a job is available into which the removed employee may be transferred.
(C) Whenever an employee is medically removed under paragraph (l)(11)
of this section, the employer shall
transfer the removed employee to a job
where the exposure to cadmium is
within the permissible levels specified
in that paragraph as soon as one becomes available.
(D) For any employee who is medically removed under the provisions of
paragraph (l)(11)(i) of this section, the
employer shall provide follow-up biological monitoring in accordance with
(l)(2)(ii)(B) of this section at least
every three months and follow-up medical examinations semi-annually at
least every six months until in a written medical opinion the examining
physician determines that either the
employee may be returned to his/her
former job status as specified under
paragraph (l)(11)(iv)–(v) of this section
or the employee must be permanently
removed from excess cadmium exposure.
(E) The employer may not return an
employee who has been medically removed for any reason to his/her former
job status until a physician determines
in a written medical opinion that continued medical removal is no longer
necessary to protect the employee’s
health.
(ii) Where an employee is found unfit
to wear a respirator under paragraph
(l)(6)(ii) of this section, the employer
shall remove the employee from work
where exposure to cadmium is above
the PEL.
(iii) Where removal is based on any
reason other than the employee’s inability to wear a respirator, the employer shall remove the employee from
work where exposure to cadmium is at
or above the action level.
(iv) Except as specified in paragraph
(l)(11)(v) of this section, no employee
who was removed because his/her level
of CdU, CdB and/or β2-M exceeded the
medical removal trigger levels in para-
graph (l)(3) or (l)(4) of this section may
be returned to work with exposure to
cadmium at or above the action level
until the employee’s levels of CdU fall
to or below 3 µg/g Cr, CdB falls to or
below 5 µg/lwb, and β2-M falls to or
below 300 µg/g Cr.
(v) However, when in the examining
physician’s opinion continued exposure
to cadmium will not pose an increased
risk to the employee’s health and there
are special circumstances that make
continued medical removal an inappropriate remedy, the physician shall fully
discuss these matters with the employee, and then in a written determination may return a worker to his/
her former job status despite what
would otherwise be unacceptably high
biological monitoring results. Thereafter, the returned employee shall continue to be provided with medical surveillance as if he/she were still on medical removal until the employee’s levels of CdU fall to or below 3 µg/g Cr,
CdB falls to or below 5 µg/lwb, and β2M falls to or below 300 µg/g Cr.
(vi) Where an employer, although not
required by paragraph (l)(11)(i)–(iii) of
this section to do so, removes an employee from exposure to cadmium or
otherwise places limitations on an employee due to the effects of cadmium
exposure on the employee’s medical
condition, the employer shall provide
the same medical removal protection
benefits to that employee under paragraph (l)(12) of this section as would
have been provided had the removal
been
required
under
paragraph
(l)(11)(i)–(iii) of this section.
(12) Medical Removal Protection Benefits (MRPB). (i) The employer shall provide MRPB for up to a maximum of 18
months to an employee each time and
while the employee is temporarily
medically removed under paragraph
(l)(11) of this section.
(ii) For purposes of this section, the
requirement that the employer provide
MRPB means that the employer shall
maintain the total normal earnings, seniority, and all other employee rights
and benefits of the removed employee,
including the employee’s right to his/
her former job status, as if the employee had not been removed from the
employee’s job or otherwise medically
limited.
148
(iii) Where, after 18 months on medical removal because of elevated biological monitoring results, the employee’s monitoring results have not declined to a low enough level to permit
the employee to be returned to his/her
former job status:
(A) The employer shall make available to the employee a medical examination pursuant to this section in
order to obtain a final medical determination as to whether the employee
may be returned to his/her former job
status or must be permanently removed from excess cadmium exposure;
and
(B) The employer shall assure that
the final medical determination indicates whether the employee may be returned to his/her former job status and
what steps, if any, should be taken to
protect the employee’s health.
(iv) The employer may condition the
provision of MRPB upon the employee’s participation in medical surveillance provided in accordance with this
section.
(13) Multiple physician review. (i) If
the employer selects the initial physician to conduct any medical examination or consultation provided to an employee under this section, the employee
may designate a second physician to:
(A) Review any findings, determinations, or recommendations of the initial physician; and
(B) Conduct such examinations, consultations, and laboratory tests as the
second physician deems necessary to
facilitate this review.
(ii) The employer shall promptly notify an employee of the right to seek a
second medical opinion after each occasion that an initial physician provided by the employer conducts a medical examination or consultation pursuant to this section. The employer
may condition its participation in, and
payment for, multiple physician review
upon the employee doing the following
within fifteen (15) days after receipt of
this notice, or receipt of the initial
physician’s written opinion, whichever
is later:
(A) Informing the employer that he
or she intends to seek a medical opinion; and
(B) Initiating steps to make an appointment with a second physician.
§ 1910.1027
(iii) If the findings, determinations,
or recommendations of the second physician differ from those of the initial
physician, then the employer and the
employee shall assure that efforts are
made for the two physicians to resolve
any disagreement.
(iv) If the two physicians have been
unable to quickly resolve their disagreement, then the employer and the
employee, through their respective
physicians, shall designate a third physician to:
(A) Review any findings, determinations, or recommendations of the other
two physicians; and
(B) Conduct such examinations, consultations, laboratory tests, and discussions with the other two physicians
as the third physician deems necessary
to resolve the disagreement among
them.
(v) The employer shall act consistently with the findings, determinations, and recommendations of the
third physician, unless the employer
and the employee reach an agreement
that is consistent with the recommendations of at least one of the
other two physicians.
(14) Alternate physician determination.
The employer and an employee or designated employee representative may
agree upon the use of any alternate
form of physician determination in lieu
of the multiple physician review provided by paragraph (l)(13) of this section, so long as the alternative is expeditious and at least as protective of the
employee.
(15) Information the employer must provide the employee. (i) The employer
shall provide a copy of the physician’s
written medical opinion to the examined employee within two weeks after
receipt thereof.
(ii) The employer shall provide the
employee with a copy of the employee’s biological monitoring results and
an explanation sheet explaining the results within two weeks after receipt
thereof.
(iii) Within 30 days after a request by
an employee, the employer shall provide the employee with the information the employer is required to provide the examining physician under
paragraph (l)(9) of this section.
149
§ 1910.1027
(16) Reporting. In addition to other
medical events that are required to be
reported on the OSHA Form No. 200,
the employer shall report any abnormal condition or disorder caused by occupational exposure to cadmium associated with employment as specified in
Chapter (V)(E) of the Reporting Guidelines for Occupational Injuries and Illnesses.
(m) Communication of cadmium hazards to employees—(1) General. In communications concerning cadmium hazards, employers shall comply with the
requirements of OSHA’s Hazard Communication Standard, 29 CFR 1910.1200,
including but not limited to the requirements concerning warning signs
and labels, material safety data sheets
(MSDS), and employee information and
training. In addition, employers shall
comply with the following requirements:
(2) Warning signs. (i) Warning signs
shall be provided and displayed in regulated areas. In addition, warning signs
shall be posted at all approaches to
regulated areas so that an employee
may read the signs and take necessary
protective steps before entering the
area.
(ii) Warning signs required by paragraph (m)(2)(i) of this section shall
bear the following information:
DANGER
CADMIUM
CANCER HAZARD
CAN CAUSE LUNG AND KIDNEY DISEASE
RESPIRATORS REQUIRED IN THIS AREA
signs required by this paragraph are illuminated, cleaned, and maintained as
necessary so that the legend is readily
visible.
(3) Warning labels. (i) Shipping and
storage containers containing cadmium, cadmium compounds, or cadmium contaminated clothing, equipment, waste, scrap, or debris shall bear
appropriate warning labels, as specified
in paragraph (m)(3)(ii) of this section.
(ii) The warning labels shall include
at least the following information:
DANGER
CONTAINS CADMIUM
CANCER HAZARD
AVOID CREATING DUST
CAN CAUSE LUNG AND KIDNEY DISEASE
(iii) Where feasible, installed cadmium products shall have a visible
label or other indication that cadmium
is present.
(4) Employee information and training.
(i) The employer shall institute a
training program for all employees who
are potentially exposed to cadmium,
assure employee participation in the
program, and maintain a record of the
contents of such program.
(ii) Training shall be provided prior
to or at the time of initial assignment
to a job involving potential exposure to
cadmium and at least annually thereafter.
(iii) The employer shall make the
training program understandable to
the employee and shall assure that
each employee is informed of the following:
(A) The health hazards associated
with cadmium exposure, with special
attention to the information incorporated in appendix A to this section;
(B) The quantity, location, manner of
use, release, and storage of cadmium in
the workplace and the specific nature
of operations that could result in exposure to cadmium, especially exposures
above the PEL;
(C) The engineering controls and
(D) The measures employees can take
to protect themselves from exposure to
cadmium, including modification of
such habits as smoking and personal
hygiene, and specific procedures the
employer has implemented to protect
employees from exposure to cadmium
such as appropriate work practices,
emergency procedures, and the provision of personal protective equipment;
(E) The purpose, proper selection, fitting, proper use, and limitations of respirators and protective clothing;
(F) The purpose and a description of
the medical surveillance program required by paragraph (l) of this section;
(G) The contents of this section and
its appendices; and
(H) The employee’s rights of access
to records under § 1910.20(e) and (g).
(iv) Additional access to information
and training program and materials.
150
(A) The employer shall make a copy
of this section and its appendices readily available without cost to all affected employees and shall provide a
copy if requested.
(B) The employer shall provide to the
Assistant Secretary or the Director,
upon request, all materials relating to
the employee information and the
training program.
(n) Recordkeeping—(1) Exposure monitoring. (i) The employer shall establish
and keep an accurate record of all air
monitoring for cadmium in the workplace.
(ii) This record shall include at least
(A) The monitoring date, duration,
and results in terms of an 8-hour TWA
of each sample taken;
(B) The name, social security number, and job classification of the employees monitored and of all other employees whose exposures the monitoring is intended to represent;
(C) A description of the sampling and
of their accuracy;
(D) The type of respiratory protective device, if any, worn by the monitored employee;
(E) A notation of any other conditions that might have affected the
monitoring results.
this record for at least thirty (30)
1910.20.
(2) Objective data for exemption from requirement for initial monitoring. (i) For
purposes of this section, objective data
are information demonstrating that a
particular product or material containing cadmium or a specific process,
operation, or activity involving cadmium cannot release dust or fumes in
concentrations at or above the action
level even under the worst-case release
conditions. Objective data can be obtained from an industry-wide study or
from laboratory product test results
from manufacturers of cadmium-containing products or materials. The data
the employer uses from an industrywide survey must be obtained under
workplace conditions closely resembling the processes, types of material,
control methods, work practices and
§ 1910.1027
environmental conditions in the employer’s current operations.
(ii) The employer shall establish and
maintain a record of the objective data
for at least 30 years.
accurate record for each employee covered by medical surveillance under
paragraph (l)(1)(i) of this section.
the following information about the
employee:
(A) Name, social security number,
and description of the duties;
opinions and an explanation sheet for
biological monitoring results;
(C) A copy of the medical history,
and the results of any physical examination and all test results that are required to be provided by this section,
including biological tests, X-rays, pulmonary function tests, etc., or that
have been obtained to further evaluate
any condition that might be related to
cadmium exposure;
(D) The employee’s medical symptoms that might be related to exposure
to cadmium; and
(E) A copy of the information provided to the physician as required by
paragraph (l)(9)(ii)–(v) of this section.
this record is maintained for the duration of employment plus thirty (30)
1910.20.
(4) Training. The employer shall certify that employees have been trained
by preparing a certification record
which includes the identity of the person trained, the signature of the employer or the person who conducted the
training, and the date the training was
completed. The certification records
shall be prepared at the completion of
training and shall be maintained on
file for one (1) year beyond the date of
training of that employee.
(5) Availability. (i) Except as otherwise provided for in this section, access
to all records required to be maintained by paragraphs (n)(1)–(4) of this
section shall be in accordance with the
provisions of 29 CFR 1910.20.
(ii) Within 15 days after a request,
the employer shall make an employee’s
medical records required to be kept by
151
§ 1910.1027
paragraph (n)(3) of this section available for examination and copying to
the subject employee, to designated
representatives, to anyone having the
specific written consent of the subject
employee, and after the employee’s
death or incapacitation, to the employee’s family members.
(6) Transfer of records. Whenever an
employer ceases to do business and
there is no successor employer to receive and retain records for the prescribed period or the employer intends
to dispose of any records required to be
preserved for at least 30 years, the employer shall comply with the requirements concerning transfer of records
set forth in 29 CFR 1910.20 (h).
(o) Observation of monitoring—(1) Employee observation. The employer shall
employee exposure to cadmium.
(2) Observation procedures. When observation of monitoring requires entry
into an area where the use of protective clothing or equipment is required,
the employer shall provide the observer
with that clothing and equipment and
shall assure that the observer uses
such clothing and equipment and complies with all other applicable safety
and health procedures.
(p) Dates—(1) Effective date. This section shall become effective December
14, 1992.
(2) Start-up dates. All obligations of
this section commence on the effective
date except as follows:
(i) Exposure monitoring. Except for
small businesses (nineteen (19) or fewer
employees), initial monitoring required
by paragraph (d)(2) of this section shall
be completed as soon as possible and in
any event no later than 60 days after
the effective date of this standard. For
small businesses, initial monitoring required by paragraph (d)(2) of this section shall be completed as soon as possible and in any event no later than 120
days after the effective date of this
standard.
(ii) Regulated areas. Except for small
business, defined under paragraph
(p)(2)(i) of this section, regulated areas
required to be established by paragraph
(e) of this section shall be set up as
soon as possible after the results of ex-
posure monitoring are known and in
the effective date of this section. For
small businesses, regulated areas required to be established by paragraph
(e) of this section shall be set up as
soon as possible after the results of exposure monitoring are known and in
the effective date of this section.
(iii) Respiratory protection. Except for
small businesses, defined under paragraph (p)(2)(i) of this section, respiratory protection required by paragraph (g) of this section shall be provided as soon as possible and in any
event no later than 90 days after the effective date of this section. For small
businesses, respiratory protection required by paragraph (g) of this section
shall be provided as soon as possible
and in any event no later than 150 days
after the effective date of this section.
(iv) Compliance program. Written compliance programs required by paragraph (f)(2) of this section shall be
completed and available for inspection
and copying as soon as possible and in
any event no later than 1 year after the
effective date of this section.
(v) Methods of compliance. The engineering controls required by paragraph
(f)(1) of this section shall be implemented as soon as possible and in any
event no later than two (2) years after
the effective date of this section. Work
practice controls shall be implemented
as soon as possible. Work practice controls that are directly related to engineering controls to be implemented in
accordance with the compliance plan
shall be implemented as soon as possible after such engineering controls
are implemented.
(vi) Hygiene and lunchroom facilities.
(A) Handwashing facilities, permanent
or temporary, shall be provided in accordance with 29 CFR 1910.141 (d)(1) and
(2) as soon as possible and in any event
no later than 60 days after the effective
date of this section.
(B) Change rooms, showers, and
lunchroom facilities shall be completed
as soon as possible and in any event no
later than 1 year after the effective
date of this section.
(vii) Employee information and training. Except for small businesses, defined under paragraph (p)(2)(i) of this
152
section, employee information and
training required by paragraph (m)(4)
of this section shall be provided as soon
as possible and in any event no later
than 90 days after the effective date of
this standard. For small businesses,
employee information and training required by paragraph (m)(4) of this
standard shall be provided as soon as
possible and in any event no later than
180 days after the effective date of this
standard.
(viii) Medical surveillance. Except for
small businesses, defined under paragraph (p)(2)(i) of this section, initial
medical examinations required by
paragraph (l) of this section shall be
provided as soon as possible and in any
event no later than 90 days after the effective date of this standard. For small
businesses, initial medical examinations required by paragraph (l) of this
section shall be provided as soon as
possible and in any event no later than
180 days after the effective date of this
standard.
(q) Appendices. (1) Appendix C to this
section is incorporated as part of this
section, and compliance with its contents is mandatory.
(2) Except where portions of appendices A, B, D, E, and F to this section
are expressly incorporated in requirements of this section, these appendices
are purely informational and are not
intended to create any additional obligations not otherwise imposed or to detract from any existing obligations.
SAFETY DATA SHEET
CADMIUM
I. Substance Identification
A. Substance: Cadmium.
B. 8-Hour, Time-weighted-average, Permissible Exposure Limit (TWA PEL):
1. TWA PEL: Five micrograms of cadmium
per cubic meter of air 5 µg/m3, time-weighted
average (TWA) for an 8-hour workday.
C. Appearance: Cadmium metal—soft, bluewhite, malleable, lustrous metal or grayishwhite powder. Some cadmium compounds
may also appear as a brown, yellow, or red
powdery substance.
II. Health Hazard Data
A. Routes of Exposure. Cadmium can cause
local skin or eye irritation. Cadmium can affect your health if you inhale it or if you
swallow it.
§ 1910.1027
B. Effects of Overexposure.
1. Short-term (acute) exposure: Cadmium
is much more dangerous by inhalation than
by ingestion. High exposures to cadmium
that may be immediately dangerous to life
or health occur in jobs where workers handle
large quantities of cadmium dust or fume;
heat cadmium-containing compounds or cadmium-coated surfaces; weld with cadmium
solders or cut cadmium-containing materials
such as bolts.
2. Severe exposure may occur before symptoms appear. Early symptoms may include
mild irritation of the upper respiratory
tract, a sensation of constriction of the
throat, a metallic taste and/or a cough. A period of 1–10 hours may precede the onset of
rapidly progressing shortness of breath,
chest pain, and flu-like symptoms with
weakness, fever, headache, chills, sweating
and muscular pain. Acute pulmonary edema
usually develops within 24 hours and reaches
a maximum by three days. If death from asphyxia does not occur, symptoms may resolve within a week.
3. Long-term (chronic) exposure. Repeated
or long-term exposure to cadmium, even at
relatively low concentrations, may result in
kidney damage and an increased risk of cancer of the lung and of the prostate.
C. Emergency First Aid Procedures.
1. Eye exposure: Direct contact may cause
redness or pain. Wash eyes immediately with
large amounts of water, lifting the upper and
lower eyelids. Get medical attention immediately.
2. Skin exposure: Direct contact may result in irritation. Remove contaminated
clothing and shoes immediately. Wash affected area with soap or mild detergent and
large amounts of water. Get medical attention immediately.
3. Ingestion: Ingestion may result in vomiting, abdominal pain, nausea, diarrhea,
headache and sore throat. Treatment for
symptoms must be administered by medical
personnel. Under no circumstances should
the employer allow any person whom he retains, employs, supervises or controls to engage in therapeutic chelation. Such treatment is likely to translocate cadmium from
pulmonary or other tissue to renal tissue.
Get medical attention immediately.
4. Inhalation: If large amounts of cadmium
are inhaled, the exposed person must be
moved to fresh air at once. If breathing has
stopped, perform cardiopulmonary resuscitation. Administer oxygen if available. Keep
the affected person warm and at rest. Get
medical attention immediately.
5. Rescue: Move the affected person from
the hazardous exposure. If the exposed person has been overcome, attempt rescue only
after notifying at least one other person of
the emergency and putting into effect established emergency procedures. Do not become
153
§ 1910.1027
a casualty yourself. Understand your emergency rescue procedures and know the location of the emergency equipment before the
need arises.
III. Employee Information
A. Protective Clothing and Equipment.
1. Respirators: You may be required to
wear a respirator for non-routine activities;
in emergencies; while your employer is in
the process of reducing cadmium exposures
through engineering controls; and where engineering controls are not feasible. If respirators are worn in the future, they must
have a joint Mine Safety and Health Administration (MSHA) and National Institute for
Occupational Safety and Health (NIOSH)
label of approval. Cadmium does not have a
detectable odor except at levels well above
the permissible exposure limits. If you can
smell cadmium while wearing a respirator,
proceed immediately to fresh air. If you experience difficulty breathing while wearing a
respirator, tell your employer.
2. Protective Clothing: You may be required to wear impermeable clothing, gloves,
foot gear, a face shield, or other appropriate
protective clothing to prevent skin contact
with cadmium. Where protective clothing is
required, your employer must provide clean
garments to you as necessary to assure that
the clothing protects you adequately. The
employer must replace or repair protective
clothing that has become torn or otherwise
damaged.
3. Eye Protection: You may be required to
wear splash-proof or dust resistant goggles
to prevent eye contact with cadmium.
B. Employer Requirements.
1. Medical: If you are exposed to cadmium
at or above the action level, your employer
is required to provide a medical examination, laboratory tests and a medical history
according to the medical surveillance provisions under paragraph (1) of this standard.
(See summary chart and tables in this appendix A.) These tests shall be provided
without cost to you. In addition, if you are
accidentally exposed to cadmium under conditions known or suspected to constitute
toxic exposure to cadmium, your employer is
required to make special tests available to
you.
2. Access to Records: All medical records
are kept strictly confidential. You or your
representative are entitled to see the records
of measurements of your exposure to cadmium. Your medical examination records
can be furnished to your personal physician
or designated representative upon request by
you to your employer.
3. Observation of Monitoring: Your employer is required to perform measurements
that are representative of your exposure to
cadmium and you or your designated representative are entitled to observe the monitoring procedure. You are entitled to observe
the steps taken in the measurement procedure, and to record the results obtained.
When the monitoring procedure is taking
place in an area where respirators or personal protective clothing and equipment are
required to be worn, you or your representative must also be provided with, and must
wear the protective clothing and equipment.
C. Employee Requirements—You will not
be able to smoke, eat, drink, chew gum or tobacco, or apply cosmetics while working
with cadmium in regulated areas. You will
also not be able to carry or store tobacco
products, gum, food, drinks or cosmetics in
regulated areas because these products easily become contaminated with cadmium
from the workplace and can therefore create
another source of unnecessary cadmium exposure.
Some workers will have to change out of
work clothes and shower at the end of the
day, as part of their workday, in order to
wash cadmium from skin and hair.
Handwashing and cadmium-free eating facilities shall be provided by the employer
and proper hygiene should always be performed before eating. It is also recommended
that you do not smoke or use tobacco products, because among other things, they naturally contain cadmium. For further information, read the labeling on such products.
IV. Physician Information
A. Introduction.—The medical surveillance
provisions of paragraph (1) generally are
aimed at accomplishing three main interrelated purposes: First, identifying employees at higher risk of adverse health effects
from excess, chronic exposure to cadmium;
second, preventing cadmium-induced disease;
and third, detecting and minimizing existing
cadmium-induced disease. The core of medical surveillance in this standard is the early
and periodic monitoring of the employee’s
biological indicators of: (a) Recent exposure
to cadmium; (b) cadmium body burden; and
(c) potential and actual kidney damage associated with exposure to cadmium.
The main adverse health effects associated
with cadmium overexposure are lung cancer
and kidney dysfunction. It is not yet known
how to adequately biologically monitor
human beings to specifically prevent cadmium-induced lung cancer. By contrast, the
kidney can be monitored to provide prevention and early detection of cadmium-induced
kidney damage. Since, for non-carcinogenic
effects, the kidney is considered the primary
target organ of chronic exposure to cadmium, the medical surveillance provisions of
this standard effectively focus on cadmiuminduced kidney disease. Within that focus,
the aim, where possible, is to prevent the
onset of such disease and, where necessary,
to minimize such disease as may already
exist. The by-products of successful prevention of kidney disease are anticipated to be
154
the reduction and prevention of other cadmium-induced diseases.
B. Health Effects.—The major health effects associated with cadmium overexposure
are described below.
1. Kidney: The most prevalent non-malignant disease observed among workers chronically exposed to cadmium is kidney dysfunction. Initially, such dysfunction is manifested as proteinuria. The proteinuria associated with cadmium exposure is most commonly characterized by excretion of low-molecular weight proteins (15,000 to 40,000 MW)
accompanied by loss of electrolytes, uric
acid, calcium, amino acids, and phosphate.
The compounds commonly excreted include:
beta-2-microglobulin (β2-M), retinol binding
protein (RBP), immunoglobulin light chains,
and lysozyme. Excretion of low molecular
weight proteins are characteristic of damage
to the proximal tubules of the kidney (Iwao
et al., 1980).
It has also been observed that exposure to
cadmium may lead to urinary excretion of
high-molecular weight proteins such as albumin, immunoglobulin G, and glycoproteins
(Ex. 29). Excretion of high-molecular weight
proteins is typically indicative of damage to
the glomeruli of the kidney. Bernard et al.,
(1979) suggest that damage to the glomeruli
and damage to the proximal tubules of the
kidney may both be linked to cadmium exposure but they may occur independently of
each other.
Several studies indicate that the onset of
low-molecular weight proteinuria is a sign of
irreversible kidney damage (Friberg et al.,
1974; Roels et al., 1982; Piscator 1984; Elinder
et al., 1985; Smith et al., 1986). Above specific
levels of β2-M associated with cadmium exposure it is unlikely that β2-M levels return to
normal even when cadmium exposure is
eliminated by removal of the individual from
the cadmium work environment (Friberg,
Ex. 29, 1990).
Some studies indicate that such proteinuria may be progressive; levels of β2-M observed in the urine increase with time even
after cadmium exposure has ceased. See, for
example, Elinder et al., 1985. Such observations, however, are not universal, and it has
been suggested that studies in which proteinuria has not been observed to progress may
not have tracked patients for a sufficiently
long time interval (Jarup, Ex. 8–661).
When cadmium exposure continues after
the
onset
of
proteinuria,
chronic
nephrotoxicity may occur (Friberg, Ex. 29).
Uremia results from the inability of the
glomerulus to adequately filter blood. This
leads to severe disturbance of electrolyte
concentrations and may lead to various clinical complications including kidney stones
(L–140–50).
After prolonged exposure to cadmium, glomerular
proteinuria,
glucosuria,
aminoaciduria,
phosphaturia,
and
§ 1910.1027
hypercalciuria may develop (Exs. 8–86, 4–28,
14–18). Phosphate, calcium, glucose, and
amino acids are essential to life, and under
normal conditions, their excretion should be
regulated by the kidney. Once low molecular
weight proteinuria has developed, these elements dissipate from the human body. Loss
of glomerular function may also occur,
manifested by decreased glomerular filtration rate and increased serum creatinine. Severe cadmium-induced renal damage may
eventually develop into chronic renal failure
and uremia (Ex. 55).
Studies in which animals are chronically
exposed to cadmium confirm the renal effects observed in humans (Friberg et al.,
1986). Animal studies also confirm problems
with calcium metabolism and related skeletal effects which have been observed among
humans exposed to cadmium in addition to
the renal effects. Other effects commonly reported in chronic animal studies include anemia,
changes
in
liver
morphology,
immunosuppression and hypertension. Some
of these effects may be associated with cofactors. Hypertension, for example, appears
to be associated with diet as well as cadmium exposure. Animals injected with cadmium have also shown testicular necrosis
(Ex. 8–86B).
2. Biological Markers
It is universally recognized that the best
measures of cadmium exposures and its effects are measurements of cadmium in biological fluids, especially urine and blood. Of
the two, CdU is conventionally used to determine body burden of cadmium in workers
without kidney disease. CdB is conventionally used to monitor for recent exposure to
cadmium. In addition, levels of CdU and CdB
historically have been used to predict the
percent of the population likely to develop
kidney disease (Thun et al., Ex. L–140–50;
WHO, Ex. 8–674; ACGIH, Exs. 8–667, 140–50).
The third biological parameter upon which
OSHA relies for medical surveillance is Beta2-microglobulin in urine (β2-M), a low molecular weight protein. Excess β2-M has been
widely accepted by physicians and scientists
as a reliable indicator of functional damage
to the proximal tubule of the kidney (Exs. 8–
447, 144–3–C, 4–47, L–140–45, 19–43–A).
Excess β2-M is found when the proximal tubules can no longer reabsorb this protein in
a normal manner. This failure of the proximal tubules is an early stage of a kind of
kidney disease that commonly occurs among
workers with excessive cadmium exposure.
Used in conjunction with biological test results indicating abnormal levels of CdU and
CdB, the finding of excess β2-M can establish
for an examining physician that any existing
kidney disease is probably cadmium-related
(Trs. 6/6/90, pp. 82–86, 122, 134). The upper limits of normal levels for cadmium in urine and
155
§ 1910.1027
cadmium in blood are 3 µg Cd/gram creatinine in urine and 5 µgCd/liter whole blood,
respectively. These levels were derived from
broad-based population studies.
Three issues confront the physicians in the
use of β2-M as a marker of kidney dysfunction and material impairment. First, there
are a few other causes of elevated levels of
β2-M not related to cadmium exposures, some
of which may be rather common diseases and
some of which are serious diseases (e.g.,
myeloma or transient flu, Exs. 29 and 8–086).
These can be medically evaluated as alternative causes (Friberg, Ex. 29). Also, there
are other factors that can cause β2-M to degrade so that low levels would result in
workers with tubular dysfunction. For example, regarding the degradation of β2-M, workers with acidic urine (pH<6) might have β2-M
levels that are within the ‘‘normal’’ range
when in fact kidney dysfunction has occurred (Ex. L–140–1) and the low molecular
weight proteins are degraded in acid urine.
Thus, it is very important that the pH of
urine be measured, that urine samples be
buffered as necessary (See appendix F.), and
that urine samples be handled correctly, i.e.,
measure the pH of freshly voided urine samples, then if necessary, buffer to pH>6 (or
above for shipping purposes), measure pH
again and then, perhaps, freeze the sample
for storage and shipping. (See also appendix
F.) Second, there is debate over the pathological significance of proteinuria, however,
most world experts believe that β2-M levels
greater than 300 µg/g Cr are abnormal
(Elinder, Ex. 55, Friberg, Ex. 29). Such levels
signify kidney dysfunction that constitutes
material impairment of health. Finally, detection of β2-M at low levels has often been
considered difficult, however, many laboratories have the capability of detecting excess
β2-M using simple kits, such as the Phadebas
Delphia test, that are accurate to levels of
100 µg β2-M/g Cr U (Ex. L–140–1).
Specific recommendations for ways to
measure β2-M and proper handling of urine
samples to prevent degradation of β2-M have
been addressed by OSHA in appendix F, in
the section on laboratory standardization.
All biological samples must be analyzed in a
laboratory that is proficient in the analysis
of that particular analyte, under paragraph
(l)(1)(iv). (See appendix F). Specifically,
under paragraph (l)(1)(iv), the employer is to
assure that the collecting and handling of biological samples of cadmium in urine (CdU),
cadmium in blood (CdB), and beta-2 microglobulin in urine (β2-M) taken from employees is collected in a manner that assures reliability. The employer must also assure that
analysis of biological samples of cadmium in
urine (CdU), cadmium in blood (CdB), and
beta-2 microglobulin in urine (β2-M) taken
from employees is performed in laboratories
with demonstrated proficiency for that particular analyte. (See appendix F.)
3. Lung and Prostate Cancer
The primary sites for cadmium-associated
cancer appear to be the lung and the prostate (L–140–50). Evidence for an association
between cancer and cadmium exposure derives from both epidemiological studies and
animal experiments. Mortality from prostate
cancer associated with cadmium is slightly
elevated in several industrial cohorts, but
the number of cases is small and there is not
clear dose-response relationship. More substantive evidence exists for lung cancer.
The major epidemiological study of lung
cancer was conducted by Thun et al., (Ex. 4–
68). Adequate data on cadmium exposures
were available to allow evaluation of doseresponse relationships between cadmium exposure and lung cancer. A statistically significant excess of lung cancer attributed to
cadmium exposure was observed in this
study even when confounding variables such
as co-exposure to arsenic and smoking habits
were taken into consideration (Ex. L–140–50).
The primary evidence for quantifying a
link between lung cancer and cadmium exposure from animal studies derives from two
rat bioassay studies; one by Takenaka et al.,
(1983), which is a study of cadmium chloride
and a second study by Oldiges and Glaser
(1990) of four cadmium compounds.
Based on the above cited studies, the U.S.
Environmental Protection Agency (EPA)
classified cadmium as ‘‘B1’’, a probable
human carcinogen, in 1985 (Ex. 4–4). The
International Agency for Research on Cancer
(IARC) in 1987 also recommended that cadmium be listed as ‘‘2A’’, a probable human
carcinogen (Ex. 4–15). The American Conference of Governmental Industrial Hygienists (ACGIH) has recently recommended that
cadmium be labeled as a carcinogen. Since
1984, NIOSH has concluded that cadmium is
possibly a human carcinogen and has recommended that exposures be controlled to
the lowest level feasible.
4. Non-carcinogenic Effects
Acute pneumonitis occurs 10 to 24 hours
after initial acute inhalation of high levels
of cadmium fumes with symptoms such as
fever and chest pain (Exs. 30, 8–86B). In extreme exposure cases pulmonary edema may
develop and cause death several days after
exposure. Little actual exposure measurement data is available on the level of airborne cadmium exposure that causes such
immediate adverse lung effects, nonetheless,
it is reasonable to believe a cadmium concentration of approximately 1 mg/m3 over an
eight hour period is ‘‘immediately dangerous’’ (55 FR 4052, ANSI; Ex. 8–86B).
In addition to acute lung effects and chronic renal effects, long term exposure to cadmium may cause other severe effects on the
respiratory system. Reduced pulmonary
function and chronic lung disease indicative
156
of emphysema have been observed in workers
who have had prolonged exposure to cadmium dust or fumes (Exs. 4–29, 4–22, 4–42, 4–
50, 4–63). In a study of workers conducted by
Kazantzis et al., a statistically significant
excess of worker deaths due to chronic bronchitis was found, which in his opinion was directly related to high cadmium exposures of
1 mg/m3 or more (Tr. 6/8/90, pp. 156–157).
Cadmium need not be respirable to constitute a hazard. Inspirable cadmium particles that are too large to be respirable but
small enough to enter the tracheobronchial
region
of
the
lung
can
lead
to
bronchoconstriction, chronic pulmonary disease, and cancer of that portion of the lung.
All of these diseases have been associated
with occupational exposure to cadmium (Ex.
8–86B). Particles that are constrained by
their size to the extra-thoracic regions of the
respiratory system such as the nose and
maxillary sinuses can be swallowed through
mucocillary clearance and be absorbed into
the body (ACGIH, Ex. 8–692). The impaction
of these particles in the upper airways can
lead to anosmia, or loss of sense of smell,
which is an early indication of overexposure
among workers exposed to heavy metals.
This condition is commonly reported among
cadmium-exposed workers (Ex. 8–86–B).
C. Medical Surveillance
In general, the main provisions of the medical surveillance section of the standard,
under paragraphs (l)(1)–(17) of the regulatory
text, are as follows:
1. Workers exposed above the action level
are covered;
2. Workers with intermittent exposures are
not covered;
3. Past workers who are covered receive biological monitoring for at least one year;
4. Initial examinations include a medical
questionnaire and biological monitoring of
cadmium in blood (CdB), cadmium in urine
(CdU), and Beta-2-microglobulin in urine (β2M);
5. Biological monitoring of these three
analytes is performed at least annually; full
medical examinations are performed biennially;
6. Until five years from the effective date
of the standard, medical removal is required
when CdU is greater than 15 µg/gram creatinine (g Cr), or CdB is greater than 15 µg/liter
whole blood (lwb), or β2-M is greater than
1500 µg/g Cr, and CdB is greater than 5 µg/lwb
or CdU is greater than 3 µg/g Cr;
7. Beginning five years after the standard
is in effect, medical removal triggers will be
reduced;
8. Medical removal protection benefits are
to be provided for up to 18 months;
9. Limited initial medical examinations
are required for respirator usage;
§ 1910.1027
10. Major provisions are fully described
under section (l) of the regulatory text; they
are outlined here as follows:
A. Eligibility
B. Biological monitoring
C. Actions triggered by levels of CdU, CdB,
and β2-M (See Summary Charts and Tables in Attachment-1.)
D. Periodic medical surveillance
E. Actions triggered by periodic medical
surveillance (See appendix A Summary
Chart and Tables in Attachment-1.)
F. Respirator usage
G. Emergency medical examinations
H. Termination examination
I. Information to physician
J. Physician’s medical opinion
K. Medical removal protection
L. Medical removal protection benefits
M. Multiple physician review
N. Alternate physician review
O. Information employer gives to employee
P. Recordkeeping
Q. Reporting on OSHA form 200
11. The above mentioned summary of the
medical surveillance provisions, the summary chart, and tables for the actions triggered at different levels of CdU, CdB and β2M (in appendix A Attachment-1) are included
only for the purpose of facilitating understanding of the provisions of paragraphs
(l)(3) of the final cadmium standard. The
summary of the provisions, the summary
chart, and the tables do not add to or reduce
the requirements in paragraph (l)(3).
D. Recommendations to Physicians
1. It is strongly recommended that patients with tubular proteinuria are counseled
on: The hazards of smoking; avoidance of
nephrotoxins and certain prescriptions and
over-the-counter medications that may exacerbate kidney symptoms; how to control diabetes and/or blood pressure; proper hydration, diet, and exercise (Ex. 19–2). A list of
prominent or common nephrotoxins is attached. (See appendix A Attachment-2.)
2. DO NOT CHELATE; KNOW WHICH
DRUGS ARE NEPHROTOXINS OR ARE ASSOCIATED WITH NEPHRITIS.
3. The gravity of cadmium-induced renal
damage is compounded by the fact there is
no medical treatment to prevent or reduce
the accumulation of cadmium in the kidney
(Ex. 8–619). Dr. Friberg, a leading world expert on cadmium toxicity, indicated in 1992,
that there is no form of chelating agent that
could be used without substantial risk. He
stated that tubular proteinuria has to be
treated in the same way as other kidney disorders (Ex. 29).
4. After the results of a workers’ biological
monitoring or medical examination are received the employer is required to provide an
information sheet to the patient, briefly explaining the significance of the results. (See
Attachment 3 of this appendix A.)
157
§ 1910.1027
5. For additional information the physician
is referred to the following additional resources:
a. The physician can always obtain a copy
of the preamble, with its full discussion of
the health effects, from OSHA’s Computerized Information System (OCIS).
b. The Docket Officer maintains a record of
the rulemaking. The Cadmium Docket (H–
057A), is located at 200 Constitution Ave.
NW., room N–2625, Washington, DC 20210;
telephone: 202–219–7894.
c. The following articles and exhibits in
particular from that docket (H–057A):
Exhibit number
Author and paper title
8–447 ..........
Lauwerys et. al., Guide for physicians, ‘‘Health Maintenance of Workers Exposed to Cadmium,’’ published by the
Cadmium Council.
Takenaka, S., H. Oldiges, H. Konig, D. Hochrainer, G. Oberdorster. ‘‘Carcinogenicity of Cadmium Chloride
Aerosols in Wistar Rats’’. JNCI 70:367–373, 1983. (32)
Thun, M.J., T.M. Schnoor, A.B. Smith, W.E. Halperin, R.A. Lemen. ‘‘Mortality Among a Cohort of U.S. Cadmium
Production Workers—An Update.’’ JNCI 74(2):325–33, 1985. (8)
Elinder, C.G., Kjellstrom, T., Hogstedt, C., et al., ‘‘Cancer Mortality of Cadmium Workers.’’ Brit. J. Ind. Med.
42:651–655, 1985. (14)
Ellis, K.J. et al., ‘‘Critical Concentrations of Cadmium in Human Renal Cortex: Dose Effect Studies to Cadmium
Smelter Workers.’’ J. Toxicol. Environ. Health 7:691–703, 1981. (76)
Ellis, K.J., S.H. Cohn and T.J. Smith. ‘‘Cadmium Inhalation Exposure Estimates: Their Significance with Respect
to Kidney and Liver Cadmium Burden.’’ J. Toxicol. Environ. Health 15:173–187, 1985.
Falck, F.Y., Jr., Fine, L.J., Smith, R.G., McClatchey, K.D., Annesley, T., England, B., and Schork, A.M. ‘‘Occupational Cadmium Exposure and Renal Status.’’ Am. J. Ind. Med. 4:541, 1983. (64)
Friberg, L., C.G. Elinder, et al., ‘‘Cadmium and Health a Toxicological and Epidemiological Appraisal, Volume I,
Exposure, Dose, and Metabolism.’’ CRC Press, Inc., Boca Raton, FL, 1986. (Available from the OSHA Technical Data Center)
Friberg, L., C.G. Elinder, et al., ‘‘Cadmium and Health: A Toxicological and Epidemiological Appraisal, Volume II,
Effects and Response.’’ CRC Press, Inc., Boca Raton, FL, 1986. (Available from the OSHA Technical Data
Center)
Elinder, C.G., ‘‘Cancer Mortality of Cadmium Workers’’, Brit. J. Ind. Med., 42, 651–655, 1985.
Thun, M., Elinder, C.G., Friberg, L, ‘‘Scientific Basis for an Occupational Standard for Cadmium, Am. J. Ind.
Med., 20; 629–642, 1991.
4–67 ............
4–68 ............
4–25 ............
4–26 ............
4–27 ............
4–28 ............
8–86A ..........
8–86B ..........
L–140–45 ....
L–140–50 ....
V. Information Sheet
The information sheet (appendix A Attachment-3.) or an equally explanatory one
should be provided to you after any biological monitoring results are reviewed by the
physician, or where applicable, after any
medical examination.
ATTACHMENT 1—APPENDIX A SUMMARY CHART
AND TABLES A AND B OF ACTIONS TRIGGERED BY BIOLOGICAL MONITORING
APPENDIX A SUMMARY CHART: SECTION (1)(3)
MEDICAL SURVEILLANCE
Categorizing Biological Monitoring Results
(A) Biological monitoring results categories are set forth in Appendix A Table A
for the periods ending December 31, 1998 and
for the period beginning January 1, 1999.
(B) The results of the biological monitoring for the initial medical exam and the
subsequent exams shall determine an employee’s biological monitoring result category.
Actions Triggered by Biological Monitoring
(A)
(i) The actions triggered by biological
monitoring for an employee are set forth in
Appendix A Table B.
(ii) The biological monitoring results for
each employee under section (1)(3) shall de-
termine the actions required for that employee. That is, for any employee in biological monitoring category C, the employer will
perform all of the actions for which there is
an X in column C of Appendix A Table B.
(iii) An employee is assigned the alphabetical category (‘‘A’’ being the lowest) depending upon the test results of the three biological markers.
(iv) An employee is assigned category A if
monitoring results for all three biological
markers fall at or below the levels indicated
in the table listed for category A.
(v) An employee is assigned category B if
any monitoring result for any of the three
biological markers fall within the range of
levels indicated in the table listed for category B, providing no result exceeds the levels listed for category B.
(vi) An employee is assigned category C if
any monitoring result for any of the three
biological markers are above the levels listed for category C.
(B) The user of Appendix A Tables A and B
should know that these tables are provided
only to facilitate understanding of the relevant provisions of paragraph (l)(3) of this
section. Appendix A Tables A and B are not
meant to add to or subtract from the requirements of those provisions.
158
APPENDIX A TABLE A—CATEGORIZATION
OF BIOLOGICAL MONITORING RESULTS
§ 1910.1027
APPLICABLE THROUGH 1998 ONLY
Monitoring result categories
Biological marker
A
Cadmium in urine (CdU) (µg/g creatinine) ........................................................
β2-microglobulin (β2–M) (µg/g creatinine) .........................................................
Cadmium in blood (CdB) (µg/liter whole blood) ...............................................
B
≤3
≤300
≤5
C
>3 and ≤15
>300 and ≤1500
>5 and ≤15
>15
>1500*
>15
* If an employee’s β2–M levels are above 1,500 µg/g creatinine, in order for mandatory medical removal to be required (See
Appendix A Table B.), either the employee’s CdU level must also be >3 µg/g creatinine or CdB level must also be >5 µg/liter
whole blood.
APPLICABLE BEGINNING JANUARY 1, 1999
Monitoring result categories
Biological marker
A
Cadmium in urine (CdU) (µg/g creatinine) ........................................................
β2-microglobulin (β2–M) (µg/g creatinine) .........................................................
Cadmium in blood (CdB) (µg/liter whole blood) ...............................................
B
≤3
≤300
≤5
C
>3 and ≤7
>300 and ≤750
>5 and ≤10
>7
>750*
>10
* If an employee’s β2–M levels are above 750 µg/g creatinine, in order for mandatory medical removal to be required (See Appendix A Table B.), either the employee’s CdU level must also be >3 µg/g creatinine or CdB level must also be >5 µg/liter whole
blood.
APPENDIX A TABLE B—ACTIONS
DETERMINED BY BIOLOGICAL MONITORING
This table presents the actions required
based on the monitoring result in Appendix
A Table A. Each item is a separate require-
ment in citing non-compliance. For example,
a medical examination within 90 days for an
employee in category B is separate from the
requirement to administer a periodic medical examination for category B employees
on an annual basis.
Monitoring result category
Required actions
A1
(1) Biological monitoring:
(a) Annual. ....................................................................................................................
(b) Semiannual .............................................................................................................
(c) Quarterly .................................................................................................................
(2) Medical examination:
(a) Biennial ...................................................................................................................
(b) Annual. ....................................................................................................................
(c) Semiannual. ............................................................................................................
(d) Within 90 days ........................................................................................................
(3) Assess within two weeks:
(a) Excess cadmium exposure ....................................................................................
(b) Work practices ........................................................................................................
(c) Personal hygiene ....................................................................................................
(d) Respirator usage ....................................................................................................
(e) Smoking history ......................................................................................................
(f) Hygiene facilities ......................................................................................................
(g) Engineering controls ...............................................................................................
(h) Correct within 30 days ............................................................................................
(i) Periodically assess exposures ................................................................................
(4) Discretionary medical removal ......................................................................................
(5) Mandatory medical removal ..........................................................................................
B1
C1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X2
1 For all employees covered by medical surveillance exclusively because of exposures prior to the effective date of this standard, if they are in Category A, the employer shall follow the requirements of paragraphs (l)(3)(i)(B) and (l)(4)(v)(A). If they are in
Category B or C, the employer shall follow the requirements of paragraphs (l)(4)(v)(B)–(C).
2 See footnote Appendix A Table A.
APPENDIX A—ATTACHMENT 2—LIST OF
MEDICATIONS
A list of the more common medications
that a physician, and the employee, may
wish to review is likely to include some of
the
following:
(1)
Anticonvulsants:
Paramethadione, phenytoin, trimethadone;
(2)
antihypertensive
drugs:
Captopril,
methyldopa;
(3)
antimicrobials:
Aminoglycosides,
amphotericin
B,
cephalosporins,
ethambutol;
(4)
antineoplastic
agents:
Cisplatin,
methotrexate, mitomycin-C, nitrosoureas,
159
§ 1910.1027
radiation; (4) sulfonamide diuretics: Acetazolamide,
chlorthalidone,
furosemide,
thiazides; (5) halogenated alkanes, hydrocarbons, and solvents that may occur in
some settings: Carbon tetrachloride, ethylene glycol, toluene; iodinated radiographic
contrast media; nonsteroidal anti-inflammatory drugs; and, (7) other miscellaneous
compounds: Acetominophen, allopurinol,
amphetamines, azathioprine, cimetidine,
cyclosporine,
lithium,
methoxyflurane,
methysergide, D-penicillamine, phenacetin,
phenendione. A list of drugs associated with
acute interstitial nephritis includes: (1)
Antimicrobial drugs: Cephalosporins, chloramphenicol,
colistin,
erythromycin,
ethambutol, isoniazid, para-aminosalicylic
acid, penicillins, polymyxin B, rifampin,
sulfonamides,
tetracyclines,
and
vancomycin; (2) other miscellaneous drugs:
Allopurinol,
antipyrene,
azathioprine,
captopril,
cimetidine,
clofibrate,
methyldopa, phenindione, phenylpropanolamine, phenytoin, probenecid, sulfinpyrazone,
sulfonamid diuretics, triamterene; and, (3)
metals: Bismuth, gold.
This list have been derived from commonly
available medical textbooks (e.g., Ex. 14–18).
The list has been included merely to facilitate the physician’s, employer’s, and employee’s understanding. The list does not
represent an official OSHA opinion or policy
regarding the use of these medications for
particular employees. The use of such medications should be under physician discretion.
ATTACHMENT 3—BIOLOGICAL MONITORING AND
MEDICAL EXAMINATION RESULTS
Employee llllllllllllllllll
Testing Date llllllllllllllll
Cadmium in Urine lll µg/g Cr—Normal
Levels: ≤3 µg/g Cr.
Cadmium in Blood lll µg/lwb—Normal
Levels: ≤5 µg/lwb.
Beta-2-microglobulin in Urine lll µg/g
Cr—Normal Levels: ≤300 µg/g Cr.
Physical Examination Results: N/A lll
Satisfactory lll Unsatisfactory lll (see
physician again).
Physician’s Review of Pulmonary Function
Test: N/A lll Normal lll Abnormal
lll.
Next biological monitoring or medical examination scheduled for lllllllllll
The biological monitoring program has
been designed for three main purposes: 1) to
identify employees at risk of adverse health
effects from excess, chronic exposure to cadmium; 2) to prevent cadmium-induced disease(s); and 3) to detect and minimize existing cadmium-induced disease(s).
The levels of cadmium in the urine and
blood provide an estimate of the total
amount of cadmium in the body. The amount
of a specific protein in the urine (beta-2microglobulin) indicates changes in kidney
function. All three tests must be evaluated
together. A single mildly elevated result
may not be important if testing at a later
time indicates that the results are normal
and the workplace has been evaluated to decrease possible sources of cadmium exposure.
The levels of cadmium or beta-2-microglobulin may change over a period of days to
months and the time needed for those
changes to occur is different for each worker.
If the results for biological monitoring are
above specific ‘‘high levels’’ [cadmium urine
greater than 10 micrograms per gram of creatinine (µg/g Cr), cadmium blood greater
than 10 micrograms per liter of whole blood
(µg/lwb), or beta-2-microglobulin greater
than 1000 micrograms per gram of creatinine
(µg/g Cr)], the worker has a much greater
chance of developing other kidney diseases.
One way to measure for kidney function is
by measuring beta-2-microglobulin in the
urine. Beta-2-microglobulin is a protein
which is normally found in the blood as it is
being filtered in the kidney, and the kidney
reabsorbs or returns almost all of the beta-2microglobulin to the blood. A very small
amount (less than 300 µg/g Cr in the urine) of
beta-2-microglobulin is not reabsorbed into
the blood, but is released in the urine. If cadmium damages the kidney, the amount of
beta-2-microglobulin in the urine increases
because the kidney cells are unable to reabsorb the beta-2-microglobulin normally. An
increase in the amount of beta-2-microglobulin in the urine is a very early sign of kidney dysfunction. A small increase in beta-2microglobulin in the urine will serve as an
early warning sign that the worker may be
absorbing cadmium from the air, cigarettes
contaminated in the workplace, or eating in
areas that are cadmium contaminated.
Even if cadmium causes permanent
changes in the kidney’s ability to reabsorb
beta-2-microglobulin, and the beta-2-microglobulin is above the ‘‘high levels’’, the loss
of kidney function may not lead to any serious health problems. Also, renal function
naturally declines as people age. The risk for
changes in kidney function for workers who
have biological monitoring results between
the ‘‘normal values’’ and the ‘‘high levels’’ is
not well known. Some people are more cadmium-tolerant, while others are more cadmium-susceptible.
For anyone with even a slight increase of
beta-2-microglobulin, cadmium in the urine,
or cadmium in the blood, it is very important to protect the kidney from further damage. Kidney damage can come from other
sources than excess cadmium-exposure so it
is also recommended that if a worker’s levels
are ‘‘high’’ he/she should receive counseling
about drinking more water; avoiding cadmium-tainted tobacco and certain medications (nephrotoxins, acetaminophen); controlling diet, vitamin intake, blood pressure
and diabetes; etc.
160
TECHNICAL GUIDELINES FOR CADMIUM
I. Cadmium Metal
A. Physical and Chemical Data.
1. Substance Identification.
Chemical name: Cadmium.
Formula: Cd.
Molecular Weight: 112.4.
Chemical Abstracts Service (CAS) Registry
No.: 7740–43–9.
Other Identifiers: RETCS EU9800000; EPA
D006; DOT 2570 53.
Synonyms: Colloidal Cadmium: Kadmium
(German): CI 77180.
2. Physical data.
Boiling point: (760 mm Hg): 765 degrees C.
Melting point: 321 degrees C.
Specific Gravity: (H2 O=@ 20 °C): 8.64.
Solubility: Insoluble in water; soluble in dilute nitric acid and in sulfuric acid.
Appearance: Soft, blue-white, malleable,
lustrous metal or grayish-white powder.
B. Fire, Explosion and Reactivity Data.
1. Fire.
Fire and Explosion Hazards: The finely divided metal is pyrophoric, that is the dust is
a severe fire hazard and moderate explosion
hazard when exposed to heat or flame. Burning material reacts violently with extinguishing agents such as water, foam, carbon
dioxide, and halons.
Flash point: Flammable (dust).
Extinguishing media: Dry sand, dry dolomite, dry graphite, or sodimum chloride.
2. Reactivity.
Conditions contributing to instability: Stable
when kept in sealed containers under normal
temperatures and pressure, but dust may ignite upon contact with air. Metal tarnishes
in moist air.
Incompatibilities: Ammonium nitrate, fused:
Reacts violently or explosively with cadmium dust below 20 °C. Hydrozoic acid: Violent explosion occurs after 30 minutes. Acids:
Reacts violently, forms hydrogen gas. Oxidizing agents or metals: Strong reaction
with cadmium dust. Nitryl fluoride at slightly elevated temperature: Glowing or white
incandescence occurs. Selenium: Reacts
exothermically. Ammonia: Corrosive reaction. Sulfur dioxide: Corrosive reaction. Fire
extinguishing agents (water, foam, carbon
dioxide, and halons): Reacts violently. Tellurium: Incandescent reaction in hydrogen atmosphere.
Hazardous decomposition products: The heated metal rapidly forms highly toxic, brownish fumes of oxides of cadmium.
C. Spill, Leak and Disposal Procedures.
1. Steps to be taken if the materials is released
or spilled. Do not touch spilled material. Stop
leak if you can do it without risk. Do not get
water inside container. For large spills, dike
spill for later disposal. Keep unnecessary
people away. Isolate hazard area and deny
entry. The Superfund Amendments and Re-
§ 1910.1027
authorization Act of 1986 Section 304 requires
that a release equal to or greater than the
reportable quantity for this substance (1
pound) must be immediately reported to the
local emergency planning committee, the
state emergency response commission, and
the National Response Center (800) 424–8802;
in Washington, DC metropolitan area (202)
426–2675.
II. Cadmium Oxide
A. Physical and Chemical Date.
1. Substance identification.
Chemical name: Cadmium Oxide.
Formula: CdO.
Molecular Weight: 128.4.
CAS No.: 1306–19–0.
Other Identifiers: RTECS EV1929500.
Synonyms: Kadmu tlenek (Polish).
2. Physical data.
Boiling point (760 mm Hg): 950 degrees C decomposes.
Melting point: 1500 °C.
Specific Gravity: (H2 O=1@20 °C): 7.0.
Solubility: Insoluble in water; soluble in
acids and alkalines.
Appearance: Red or brown crystals.
1. Fire.
Fire and Explosion Hazards: Negligible fire
hazard when exposed to heat or flame.
Flash point: Nonflammable.
Extinguishing media: Dry chemical, carbon
dioxide, water spray or foam.
2. Reactivity.
Conditions contributing to instability: Stable
under normal temperatures and pressures.
Incompatibilities: Magnesium may reduce
CdO2 explosively on heating.
Hazardous decomposition products: Toxic
fumes of cadmium.
C. Spill Leak and Disposal Procedures.
1. Steps to be taken if the material is released
leak if you can do it without risk. For small
spills, take up with sand or other absorbent
material and place into containers for later
disposal. For small dry spills, use a clean
shovel to place material into clean, dry container and then cover. Move containers from
spill area. For larger spills, dike far ahead of
spill for later disposal. Keep unnecessary
people away. Isolate hazard area and deny
entry. The Superfund Amendments and Reauthorization Act of 1986 Section 304 requires
that a release equal to or greater than the
reportable quantity for this substance (1
pound) must be immediately reported to the
local emergency planning committee, the
state emergency response commission, and
the National Response Center (800) 424–8802;
in Washington, DC metropolitan area (202)
426–2675.
III. Cadmium Sulfide.
Chemical name: Cadmium sulfide.
Formula: CdS.
161
§ 1910.1027
Molecular weight: 144.5.
CAS No. 1306–23–6.
Other Identifiers: RTECS EV3150000.
Synonyms: Aurora yellow; Cadmium Golden
366; Cadmium Lemon Yellow 527; Cadmium
Orange; Cadmium Primrose 819; Cadmium
Sulphide; Cadmium Yellow; Cadmium Yellow
000; Cadmium Yellow Conc. Deep; Cadmium
Yellow Conc. Golden; Cadmium Yellow Conc.
Lemon; Cadmium Yellow Conc. Primrose;
Cadmium Yellow Oz. Dark; Cadmium Yellow
Primrose 47–1400; Cadmium Yellow 10G
Conc.; Cadmium Yellow 892; Cadmopur Golden Yellow N; Cadmopur Yellow: Capsebon;
C.I. 77199; C.I. Pigment Orange 20; CI Pigment Yellow 37; Ferro Lemon Yellow; Ferro
Orange Yellow; Ferro Yellow; Greenockite;
NCI–C02711.
2. Physical data.
Boiling point (760 mm. Hg): sublines in N2 at
980 °C.
Melting point: 1750 degrees C (100 atm).
Specific Gravity: (H2 O=1@ 20 °C): 4.82.
Solubility: Slightly soluble in water; soluble
in acid.
Appearance: Light yellow or yellow-orange
crystals.
1. Fire.
Fire and Explosion Hazards: Neglible fire
hazard when exposed to heat or flame.
Flash point: Nonflammable.
2. Reactivity.
Conditions contributing to instability: Generally non-reactive under normal conditions.
Reacts with acids to form toxic hydrogen
sulfide gas.
Incompatibilities: Reacts vigorously with
iodinemonochloride.
Hazardous decomposition products: Toxic
fumes of cadmium and sulfur oxides.
1. Steps to be taken if the material is released
leak if you can do it without risk. For small,
dry spills, with a clean shovel place material
into clean, dry container and cover. Move
containers from spill area. For larger spills,
dike far ahead of spill for later disposal.
Keep unnecessary people away. Isolate hazard and deny entry.
IV. Cadmium Chloride.
Chemcail name: Cadmium chloride.
Formula: CdC12.
Molecular weight: 183.3.
CAS No. 10108–64–2.
Other Identifiers: RTECS EY0175000.
Synonyms: Caddy; Cadmium dichloride; NA
2570 (DOT); UI-CAD; dichlorocadmium.
2. Physical data.
Boiling point (760 mm Hg): 960 degrees C.
Melting point: 568 degrees C.
Specific Gravity: (H2 O=1 @ 20 °C): 4.05.
Solubility: Soluble in water (140 g/100 cc);
soluble in acetone.
Appearance: Small, white crystals.
1. Fire.
Fire and Explosion Hazards: Negligible fire
and negligible explosion hazard in dust form
when exposed to heat or flame.
Flash point: Nonflamable.
2. Reactivity.
Conditions contributing to instability: Generally stable under normal temperatures and
pressures.
Incompatibilities: Bromine triflouride rapidly attacks cadmium chloride. A mixture of
potassium and cadmium chloride may
produce a strong explosion on impact.
Hazardous decomposition products: Thermal
ecompostion may release toxic fumes of hydrogen chloride, chloride, chlorine or oxides
of cadmium.
1. Steps to be taken if the materials is released
leak if you can do it without risk. For small,
dry spills, with a clean shovel place material
into clean, dry container and cover. Move
containers from spill area. For larger spills,
dike far ahead of spill for later disposal.
Keep unnecessary people away. Isolate hazard and deny entry. The Superfund Amendments and Reauthorization Act of 1986 Section 304 requires that a release equal to or
greater than the reportable quantity for this
substance (100 pounds) must be immediately
reported to the local emergency planning
committee, the state emergency response
commission, and the National Response Center (800) 424–8802; in Washington, DC Metropolitan area (202) 426–2675.
APPENDIX C TO § 1910.1027 [RESERVED]
APPENDIX
D TO § 1910.1027—OCCUPATIONAL HEALTH HISTORY INTERVIEW
WITH REFERENCE TO CADMIUM EXPOSURE
Directions
(To be read by employee and signed prior to
the interview)
Please answer the questions you will be
asked as completely and carefully as you
can. These questions are asked of everyone
who works with cadmium. You will also be
asked to give blood and urine samples. The
doctor will give your employer a written
opinion on whether you are physically capable of working with cadmium. Legally, the
doctor cannot share personal information
you may tell him/her with your employer.
The following information is considered
strictly confidential. The results of the tests
162
will go to you, your doctor and your employer. You will also receive an information
sheet explaining the results of any biological
monitoring or physical examinations performed.
If you are just being hired, the results of
this interview and examination will be used
to:
(1) Establish your health status and see if
working with cadmium might be expected to
cause unusual problems,
(2) Determine your health status today and
see if there are changes over time,
(3) See if you can wear a respirator safely.
If you are not a new hire:
OSHA says that everyone who works with
cadmium can have periodic medical examinations performed by a doctor. The reasons
for this are:
(a) If there are changes in your health, either because of cadmium or some other reason, to find them early,
(b) to prevent kidney damage.
Please sign below.
I have read these directions and understand them:
Employee signature
Date
Thank you for answering these questions.
(Suggested Format)
Name llllllllllllllllllll
Age lllllllllllllllllllll
Social Security # llllllllllllll
Company llllllllllllllllll
Job lllllllllllllllllllll
Type of Preplacement Exam:
[ ] Periodic
[ ] Termination
[ ] Initial
[ ] Other
Blood Pressure lllllllllllllll
Pulse Rate lllllllllllllllll
1. How long have you worked at the job listed above?
[ ] Not yet hired
[ ] Number of months
[ ] Number of years
2. Job Duties etc.
3. Have you ever been told by a doctor that
you had bronchitis?
[ ] Yes
[ ] No
If yes, how long ago?
[ ] Number of years
you had emphysema?
[ ] Yes
[ ] No
§ 1910.1027
[ ] Number of years
you had other lung problems?
[ ] Yes
[ ] No
If yes, please describe type of lung problems and when you had these problems
6. In the past year, have you had a cough?
[ ] Yes
[ ] No
If yes, did you cough up sputum?
[ ] Yes
[ ] No
If yes, how long did the cough with sputum
production last?
[ ] Less than 3 months
[ ] 3 months or longer
If yes, for how many years have you had
episodes of cough with sputum production lasting this long?
[ ] Less than one
[ ]1
[ ]2
[ ] Longer than 2
7. Have you ever smoked cigarettes?
[ ] Yes
[ ] No
8. Do you now smoke cigarettes?
[ ] Yes
[ ] No
9. If you smoke or have smoked cigarettes,
for how many years have you smoked, or
did you smoke?
[ ] Less than 1 year
[ ] Number of years
What is or was the greatest number of
packs per day that you have smoked?
[ ] Number of packs
If you quit smoking cigarettes, how many
years ago did you quit?
[ ] Number of years
How many packs a day do you now smoke?
[ ] Number of packs per day
you had a kidney or urinary tract disease
or disorder?
[ ] Yes
[ ] No
11. Have you ever had any of these disorders?
Kidney stones ................ [ ] Yes [ ] No
Protein in urine ............. [ ] Yes [ ] No
Blood in urine ................ [ ] Yes [ ] No
Difficulty urinating ....... [ ] Yes [ ] No
Other kidney/Urinary
[ ] Yes [ ] No
disorders.
Please describe problems, age, treatment,
and follow up for any kidney or urinary
problems you have had:
163
§ 1910.1027
12. Have you ever been told by a doctor or
other health care provider who took your
blood pressure that your blood pressure
was high?
[ ] Yes
[ ] No
13. Have you ever been advised to take any
blood pressure medication?
[ ] Yes
[ ] No
14. Are you presently taking any blood pressure medication?
[ ] Yes
[ ] No
15. Are you presently taking any other medication?
[ ] Yes
[ ] No
16. Please list any blood pressure or other
medications and describe how long you
have been taking each one:
Medicine:
How Long Taken
you have diabetes? (sugar in your blood
or urine)
[ ] Yes
[ ] No
If yes, do you presently see a doctor about
your diabetes?
[ ] Yes
[ ] No
If yes, how do you control your blood
sugar?
[ ] Diet alone
[ ] Diet plus oral medicine
[ ] Diet plus insulin (injection)
you had:
Anemia .......................... [ ] Yes [ ] No
A low blood count? ........ [ ] Yes [ ] No
19. Do you presently feel that you tire or run
out of energy sooner than normal or
sooner than other people your age?
[ ] Yes
[ ] No
If yes, for how long have you felt that you
tire easily?
[ ] Number of years
20. Have you given blood within the last
year?
[ ] Yes
[ ] No
If yes, how many times?
[ ] Number of times
How long ago was the last time you gave
blood?
[ ] Less than 1 month
21. Within the last year have you had any injuries with heavy bleeding?
[ ] Yes
[ ] No
[ ] Less than 1 month
[ ] Nnumber of months
Describe: llllllllllllllllll
22. Have you recently had any surgery?
[ ] Yes
[ ] No
If yes, please describe: lllllllllll
23. Have you seen any blood lately in your
stool or after a bowel movement?
[ ] Yes
[ ] No
24. Have you ever had a test for blood in your
stool?
[ ] Yes
[ ] No
If yes, did the test show any blood in the
stool?
[ ] Yes
[ ] No
What further evaluation and treatment were
done? lllllllllllllllllll
The following questions pertain to the
ability to wear a respirator. Additional information for the physician can be found in
The Respiratory Protective Devices Manual.
you have asthma?
[ ] Yes
[ ] No
If yes, are you presently taking any medication for asthma? Mark all that apply.
[ ] Shots
[ ] Pills
[ ] Inhaler
26. Have you ever had a heart attack?
[ ] Yes
[ ] No
[ ] Number of years
27. Have you ever had pains in your chest?
[ ] Yes
[ ] No
If yes, when did it usually happen?
[ ] While resting
[ ] While working
[ ] While exercising
[ ] Activity didn’t matter
28. Have you ever had a thyroid problem?
[ ] Yes
[ ] No
29. Have you ever had a seizure or fits?
[ ] Yes
[ ] No
164
30. Have you ever had a stroke (cerebrovascular accident)?
[ ] Yes
[ ] No
31. Have you ever had a ruptured eardrum or
a serious hearing problem?
[ ] Yes
[ ] No
32. Do you now have a claustrophobia, meaning fear of crowded or closed in spaces or
any psychological problems that would
make it hard for you to wear a respirator?
[ ] Yes
[ ] No
The following questions pertain to reproductive history.
33. Have you or your partner had a problem
conceiving a child?
[ ] Yes
[ ] No
If yes, specify:
[ ] Self
[ ] Present mate
[ ] Previous mate
34. Have you or your partner consulted a
physician for a fertility or other reproductive problem?
[ ] Yes
[ ] No
If yes, specify who consulted the physician:
[ ] Self
[ ] Spouse/partner
[ ] Self and partner
If yes, specify diagnosis made: lllllll
35. Have you or your partner ever conceived
a child resulting in a miscarriage, still
birth or deformed offspring?
[ ] Yes
[ ] No
If yes, specify:
[ ] Miscarriage
[ ] Still birth
[ ] Deformed offspring
If outcome was a deformed offspring, please
specify type: lllllllllllllll
36. Was this outcome a result of a pregnancy
of:
[ ] Yours with present partner
[ ] Yours with a previous partner
37. Did the timing of any abnormal pregnancy outcome coincide with present employment?
[ ] Yes
[ ] No
List dates of occurrences: llllllllll
38. What is the occupation of your spouse or
partner?
§ 1910.1027
For Women Only
39. Do you have menstrual periods?
[ ] Yes
[ ] No
Have you had menstrual irregularities?
[ ] Yes
[ ] No
If yes, specify type: lllllllllllll
If yes, what was the approximated date this
problem began? llllllllllllll
Approximate date problem stopped?
llll
For Men Only
40. Have you ever been diagnosed by a physician as having prostate gland problem(s)?
[ ] Yes
[ ] No
If yes, please describe type of problem(s) and
what was done to evaluate and treat the
problem(s): llllllllllllllll
APPENDIX E TO § 1910.1027—CADMIUM IN
WORKPLACE ATMOSPHERES
Method Number: ID–189
Matrix: Air
OSHA Permissible Exposure Limits: 5 µg/m3
(TWA), 2.5 µg/m3 (Action Level TWA)
Collection Procedure: A known volume of air
is drawn through a 37-mm diameter filter
cassette containing a 0.8-µm mixed cellulose ester membrane filter (MCEF).
Recommended Air Volume: 960 L
Recommended Sampling Rate: 2.0 L/min
Analytical Procedure: Air filter samples are
digested with nitric acid. After digestion,
a small amount of hydrochloric acid is
added. The samples are then diluted to
volume with deionized water and analyzed by either flame atomic absorption
spectroscopy (AAS) or flameless atomic
absorption spectroscopy using a heated
graphite furnace atomizer (AAS-HGA).
Detection Limits:
Qualitative: 0.2 µg/m3 for a 200 L sample by
Flame AAS, 0.007 µg/m3 for a 60 L sample
by AAS–HGA
Quantitative: 0.70 µg/m3 for a 200 L sample by
Flame AAS, 0.025 µg/m3 for a 60 L sample
by AAS–HGA
Precision and Accuracy: (Flame AAS Analysis and AAS–HGA Analysis):
Validation Level: 2.5 to 10 µg/m3 for a 400 L
air vol, 1.25 to 5.0 µg/m3 for a 60 L air vol
CV1 (pooled): 0.010, 0.043
Analytical Bias: +4.0%, ¥5.8%
Overall Analytical Error:±6.0%, ±14.2%
Method Classification: Validated
165
§ 1910.1027
Date: June, 1992
Inorganic Service Branch II, OSHA Salt
Lake Technical Center, Salt Lake City, Utah
by USDOL-OSHA. Similar products from
other sources can be substituted.
1. INTRODUCTION
1.1. Scope
This method describes the collection of
airborne elemental cadmium and cadmium
compounds on 0.8-µm mixed cellulose ester
membrane filters and their subsequent analysis by either flame atomic absorption spectroscopy (AAS) or flameless atomic absorption spectroscopy using a heated graphite
furnace atomizer (AAS-HGA). It is applicable
for both TWA and Action Level TWA Permissible Exposure Level (PEL) measurements.
The two atomic absorption analytical techniques included in the method do not differentiate between cadmium fume and cadmium dust samples. They also do not differentiate between elemental cadmium and
its compounds.
1.2. Principle
Airborne elemental cadmium and cadmium
compounds are collected on a 0.8-µm mixed
cellulose ester membrane filter (MCEF). The
air filter samples are digested with concentrated nitric acid to destroy the organic
matrix and dissolve the cadmium analytes.
After digestion, a small amount of concentrated hydrochloric acid is added to help
dissolve other metals which may be present.
The samples are diluted to volume with deionized water and then aspirated into the
oxidizing air/acetylene flame of an atomic
absorption spectrophotometer for analysis of
elemental cadmium.
If the concentration of cadmium in a sample solution is too low for quantitation by
this flame AAS analytical technique, and the
sample is to be averaged with other samples
for TWA calculations, aliquots of the sample
and a matrix modifier are later injected onto
a L’vov platform in a pyrolytically-coated
graphite tube of a Zeeman atomic absorption
spectrophotometer/graphite furnace assembly for analysis of elemental cadmium. The
matrix modifier is added to stabilize the cadmium metal and minimize sodium chloride
as an interference during the high temperature charring step of the analysis (5.1., 5.2.).
1.3. History
Previously, two OSHA sampling and analytical methods for cadmium were used concurrently (5.3., 5.4.). Both of these methods
also required 0.8-µm mixed cellulose ester
membrane filters for the collection of air
samples. These cadmium air filter samples
were analyzed by either flame atomic absorption spectroscopy (5.3.) or inductively
coupled plasma/atomic emission spectroscopy (ICP-AES) (5.4.). Neither of these two
analytical methods have adequate sensitivity for measuring workplace exposure to
airborne cadmium at the new lower TWA and
Action Level TWA PEL levels when consecutive samples are taken on one employee and
the sample results need to be averaged with
other samples to determine a single TWA.
The inclusion of two atomic absorption analytical techniques in the new sampling and
analysis method for airborne cadmium permits quantitation of sample results over a
broad range of exposure levels and sampling
periods. The flame AAS analytical technique
included in this method is similar to the previous procedure given in the General Metals
Method ID–121 (5.3.) with some modifications. The sensitivity of the AAS-HGA analytical technique included in this method is
adequate to measure exposure levels at 1/10
the Action Level TWA, or lower, when less
than full-shift samples need to be averaged
together.
1.4. Properties (5.5.)
Elemental cadmium is a silver-white, bluetinged, lustrous metal which is easily cut
with a knife. It is slowly oxidized by moist
air to form cadmium oxide. It is insoluble in
water, but reacts readily with dilute nitric
acid. Some of the physical properties and
other descriptive information of elemental
cadmium are given below:
CAS No. .............................................7440–43–9
Atomic Number ...........................................48
Atomic Symbol...........................................Cd
Atomic Weight .......................................112.41
Melting Point ........................................321 °C
Boiling Point .........................................765 °C
Density ..................................8.65 g/mL (25 °C)
The properties of specific cadmium compounds are described in reference 5.5.
1.5. Method Performance
A synopsis of method performance is presented below. Further information can be
found in Section 4.
1.5.1. The qualitative and quantitative detection limits for the flame AAS analytical
technique are 0.04 µg (0.004 µg/mL) and 0.14 µg
(0.014 µg/mL) cadmium, respectively, for a 10
mL solution volume. These correspond, respectively, to 0.2 µg/m3 and 0.70 µg/m3 for a
200 L air volume.
1.5.2. The qualitative and quantitative detection limits for the AAS-HGA analytical
technique are 0.44 ng (0.044 ng/mL) and 1.5 ng
(0.15 ng/mL) cadmium, respectively, for a 10
mL solution volume. These correspond, respectively, to 0.007 µg/m3 and 0.025 µg/m3 for
a 60 L air volume.
1.5.3. The average recovery by the flame
AAS analytical technique of 17 spiked MCEF
166
samples containing cadmium in the range of
0.5 to 2.0 times the TWA target concentration of 5 µg/m3 (assuming a 400 L air volume)
was 104.0% with a pooled coefficient of variation (CV1) of 0.010. The flame analytical
technique exhibited a positive bias of +4.0%
for the validated concentration range. The
overall analytical error (OAE) for the flame
AAS analytical technique was ±6.0%.
1.5.4. The average recovery by the AASHGA analytical technique of 18 spiked MCEF
samples containing cadmium in the range of
0.5 to 2.0 times the Action Level TWA target
concentration of 2.5 µg/m3 (assuming a 60 L
air volume) was 94.2% with a pooled coefficient of variation (CV1) of 0.043. The AASHGA analytical technique exhibited a negative bias of ¥5.8% for the validated concentration range. The overall analytical
error (OAE) for the AAS-HGA analytical
technique was ±14.2%.
1.5.5. Sensitivity in flame atomic absorption is defined as the characteristic concentration of an element required to produce
a signal of 1% absorbance (0.0044 absorbance
units). Sensitivity values are listed for each
element by the atomic absorption spectrophotometer manufacturer and have proved
to be a very valuable diagnostic tool to determine if instrumental parameters are optimized and if the instrument is performing up
to specification. The sensitivity of the spectrophotometer used in the validation of the
flame AAS analytical technique agreed with
the manufacturer specifications (5.6.); the 2
µg/mL cadmium standard gave an absorbance
reading of 0.350 abs. units.
1.5.6. Sensitivity in graphite furnace atomic absorption is defined in terms of the characteristic mass, the number of picograms required to give an integrated absorbance
value of 0.0044 absorbance-second (5.7.). Data
suggests that under Stabilized Temperature
Platform Furnace (STPF) conditions (see
Section 1.6.2.), characteristic mass values are
transferable between properly functioning
instruments to an accuracy of about 20%
(5.2.). The characteristic mass for STPF
analysis of cadmium with Zeeman background correction listed by the manufacturer of the instrument used in the validation of the AAS-HGA analytical technique
was 0.35 pg. The experimental characteristic
mass value observed during the determination of the working range and detection limits of the AAS-HGA analytical technique was
0.41 pg.
1.6. Interferences
1.6.1. High concentrations of silicate interfere in determining cadmium by flame AAS
(5.6.). However, silicates are not significantly
soluble in the acid matrix used to prepare
the samples.
1.6.2. Interferences, such as background absorption, are reduced to a minimum in the
AAS-HGA analytical technique by taking
§ 1910.1027
full advantage of the Stabilized Temperature
Platform Furnace (STPF) concept. STPF includes all of the following parameters (5.2.):
a. Integrated Absorbance,
b. Fast Instrument Electronics and Sampling
Frequency,
c. Background Correction,
d. Maximum Power Heating,
e. Atomization off the L’vov platform in a
pyrolytically coated graphite tube,
f. Gas Stop during Atomization,
g. Use of Matrix Modifiers.
1.7. Toxicology (5.14.)
Information listed within this section is
synopsis of current knowledge of the physiological effects of cadmium and is not intended to be used as the basis for OSHA policy. IARC classifies cadmium and certain of
its compounds as Group 2A carcinogens
(probably carcinogenic to humans). Cadmium fume is intensely irritating to the respiratory tract. Workplace exposure to cadmium can cause both chronic and acute effects.
Acute
effects
include
tracheobronchitis, pneumonitis, and pulmonary edema. Chronic effects include anemia, rhinitis/anosmia, pulmonary emphysema, proteinuria and lung cancer. The primary target organs for chronic disease are
the kidneys (non-carcinogenic) and the lungs
(carcinogenic).
2. SAMPLING
2.1. Apparatus
2.1.1. Filter cassette unit for air sampling:
A 37-mm diameter mixed cellulose ester
membrane filter with a pore size of 0.8-µm
contained in a 37-mm polystyrene two- or
three-piece cassette filter holder (part no.
MAWP 037 A0, Millipore Corp., Bedford, MA).
The filter is supported with a cellulose
backup pad. The cassette is sealed prior to
use with a shrinkable gel band.
2.1.2. A calibrated personal sampling pump
whose flow is determined to an accuracy of
±5% at the recommended flow rate with the
filter cassette unit in line.
2.2. Procedure
2.2.1. Attach the prepared cassette to the
calibrated sampling pump (the backup pad
should face the pump) using flexible tubing.
Place the sampling device on the employee
such that air is sampled from the breathing
zone.
2.2.2. Collect air samples at a flow rate of
2.0 L/min. If the filter does not become overloaded, a full-shift (at least seven hours)
sample is strongly recommended for TWA
and Action Level TWA measurements with a
maximum air volume of 960 L. If overloading
occurs, collect consecutive air samples for
shorter sampling periods to cover the full
workshift.
167
§ 1910.1027
2.2.3. Replace the end plugs into the filter
cassettes
immediately
after
sampling.
Record the sampling conditions.
2.2.4. Securely wrap each sample filter cassette end-to-end with an OSHA Form 21 sample seal.
2.2.5. Submit at least one blank sample
with each set of air samples. The blank sample should be handled the same as the other
samples except that no air is drawn through
it.
2.2.6. Ship the samples to the laboratory
for analysis as soon as possible in a suitable
container designed to prevent damage in
transit.
3. ANALYSIS
3.1.1. Wear safety glasses, protective clothing and gloves at all times.
3.1.2. Handle acid solutions with care. Handle all cadmium samples and solutions with
extra care (see Sect. 1.7.). Avoid their direct
contact with work area surfaces, eyes, skin
and clothes. Flush acid solutions which contact the skin or eyes with copious amounts
of water.
3.1.3. Perform all acid digestions and acid
dilutions in an exhaust hood while wearing a
face shield. To avoid exposure to acid vapors,
do not remove beakers containing concentrated acid solutions from the exhaust
hood until they have returned to room temperature and have been diluted or emptied.
3.1.4. Exercise care when using laboratory
glassware. Do not use chipped pipets, volumetric flasks, beakers or any glassware with
sharp edges exposed in order to avoid the
possibility of cuts or abrasions.
3.1.5. Never pipet by mouth.
3.1.6. Refer to the instrument instruction
manuals and SOPs (5.8., 5.9.) for proper and
safe operation of the atomic absorption spectrophotometer, graphite furnace atomizer
and associated equipment.
3.1.7. Because metallic elements and other
toxic substances are vaporized during AAS
flame or graphite furnace atomizer operation, it is imperative that an exhaust vent
be used. Always ensure that the exhaust system is operating properly during instrument
use.
3.2. Apparatus for Sample and Standard
Preparation
3.2.1. Hot plate, capable of reaching 150 °C,
installed in an exhaust hood.
3.2.2. Phillips beakers, 125 mL.
3.2.3. Bottles, narrow-mouth, polyethylene
or glass with leakproof caps: used for storage
of standards and matrix modifier.
3.2.4. Volumetric flasks, volumetric pipets,
beakers and other associated general laboratory glassware.
3.2.5. Forceps and other associated general
laboratory equipment.
3.3. Apparatus for Flame AAS Analysis
3.3.1. Atomic absorption spectrophotometer consisting of a(an):
Nebulizer and burner head
Pressure regulating devices capable of maintaining constant oxidant and fuel pressures
Optical system capable of isolating the desired wavelength of radiation (228.8 nm)
Adjustable slit
Light measuring and amplifying device
Display, strip chart, or computer interface
for indicating the amount of absorbed radiation
Cadmium
hollow
cathode
lamp
or
electrodeless discharge lamp (EDL) and
power supply
3.3.2. Oxidant: compressed air, filtered to
remove water, oil and other foreign substances.
3.3.3. Fuel: standard commercially available tanks of acetylene dissolved in acetone;
tanks should be equipped with flash arresters.
CAUTION: Do not use grades of acetylene
containing solvents other than acetone because they may damage the PVC tubing used
in some instruments.
3.3.4. Pressure-reducing valves: two gauge,
two-stage pressure regulators to maintain
fuel and oxidant pressures somewhat higher
than the controlled operating pressures of
the instrument.
3.3.5. Exhaust vent installed directly above
the spectrophotometer burner head.
3.4. Apparatus for AAS–HGA Analysis
3.4.1. Atomic absorption spectrophotometer consisting of a(an):
Heated graphite furnace atomizer (HGA)
with argon purge system
Pressure-regulating devices capable of maintaining constant argon purge pressure
Optical system capable of isolating the desired wavelength of radiation (228.8 nm)
Adjustable slit
Light measuring and amplifying device
Display, strip chart, or computer interface
for indicating the amount of absorbed radiation (as integrated absorbance, peak area)
Background corrector: Zeeman or deuterium
arc. The Zeeman background corrector is
recommended
Cadmium
hollow
cathode
lamp
or
electrodeless discharge lamp (EDL) and
power supply
Autosampler capable of accurately injecting
5 to 20 µL sample aliquots onto the L’vov
Platform in a graphite tube
3.4.2. Pyrolytically coated graphite tubes
containing solid, pyrolytic L’vov platforms.
3.4.3. Polyethylene sample cups, 2.0 to 2.5
mL, for use with the autosampler.
3.4.4. Inert purge gas for graphite furnace
atomizer: compressed gas cylinder of purified
argon.
168
3.4.5. Two gauge, two-stage pressure regulator for the argon gas cylinder.
3.4.6. Cooling water supply for graphite furnace atomizer.
3.4.7. Exhaust vent installed directly above
the graphite furnace atomizer.
same diluting solution. A suggested method
of preparation of the working standards is
given below.
3.5. Reagents
All reagents should be ACS analytical reagent grade or better.
3.5.1. Deionized water with a specific conductance of less than 10 µS.
3.5.2. Concentrated nitric acid, HNO3.
3.5.3. Concentrated hydrochloric acid, HCl.
3.5.4. Ammonium phosphate, monobasic,
NH4 H2 PO4.
3.5.5. Magnesium nitrate, Mg(NO3)2 • 6H2 O.
3.5.6. Diluting solution (4% HNO3, 0.4%
HCl): Add 40 mL HNO3 and 4 mL HCl carefully to approximately 500 mL deionized
water and dilute to 1 L with deionized water.
3.5.7. Cadmium standard stock solution,
1,000 µg/mL: Use a commercially available
certified 1,000 µg/mL cadmium standard or,
alternatively, dissolve 1.0000 g of cadmium
metal in a minimum volume of 1:1 HCl and
dilute to 1 L with 4% HNO3. Observe expiration dates of commercial standards. Properly
dispose of commercial standards with no expiration dates or prepared standards one
year after their receipt or preparation date.
3.5.8. Matrix modifier for AAS–HGA analysis: Dissolve 1.0 g NH4 H2 PO4 and 0.15 g
Mg(NO3)2 · 6H2 O in approximately 200 mL deionized water. Add 1 mL HNO3 and dilute to
500 mL with deionized water.
3.5.9 Nitric Acid, 1:1 HNO3/DI H2 O mixture: Carefully add a measured volume of
concentrated HNO3 to an equal volume of DI
H2 O.
3.5.10. Nitric acid, 10% v/v: Carefully add
100 mL of concentrated HNO3 to 500 mL of DI
H2 O and dilute to 1 L.
3.6. Glassware Preparation
3.6.1. Clean Phillips beakers by refluxing
with 1:1 nitric acid on a hot plate in a fume
hood. Thoroughly rinse with deionized water
and invert the beakers to allow them to
drain dry.
3.6.2. Rinse volumetric flasks and all other
glassware with 10% nitric acid and deionized
water prior to use.
3.7. Standard Preparation for Flame AAS
Analysis
3.7.1. Dilute stock solutions: Prepare 1, 5,
10 and 100 µg/mL cadmium standard stock solutions by making appropriate serial dilutions of 1,000 µg/mL cadmium standard stock
solution with the diluting solution described
in Section 3.5.6.
3.7.2. Working standards: Prepare cadmium
working standards in the range of 0.02 to 2.0
µg/mL by making appropriate serial dilutions of the dilute stock solutions with the
§ 1910.1027
Working standard
Std solution
Aliquot
Final vol.
(µg/mL)
(µg/mL)
(mL)
(mL)
0.02 ................................
0.05 ................................
0.1 ..................................
0.2 ..................................
0.5 ..................................
1 .....................................
2 .....................................
1
5
10
10
10
100
100
10
5
5
10
25
5
10
500
500
500
500
500
500
500
Store the working standards in 500-mL,
narrow-mouth polyethylene or glass bottles
with leak proof caps. Prepare every twelve
months.
3.8. Standard Preparation for AAS–HGA
Analysis
3.8.1. Dilute stock solutions: Prepare 10, 100
and 1,000 ng/mL cadmium standard stock solutions by making appropriate ten-fold serial
dilutions of the 1,000 µg/mL cadmium standard stock solution with the diluting solution
described in Section 3.5.6.
3.8.2. Working standards: Prepare cadmium
working standards in the range of 0.2 to 20
ng/mL by making appropriate serial dilutions of the dilute stock solutions with the
same diluting solution. A suggested method
of preparation of the working standards is
given below.
Working standard
(ng/mL)
0.2 ..................................
0.5 ..................................
1 .....................................
2 .....................................
5 .....................................
10 ...................................
20 ...................................
Std solution
Aliquot
Final vol.
(ng/mL)
(mL)
(mL)
10
10
10
100
100
100
1,000
2
5
10
2
5
10
2
100
100
100
100
100
100
100
Store the working standards in narrowmouth polyethylene or glass bottles with
leakproof caps. Prepare monthly.
3.9. Sample Preparation
3.9.1. Carefully transfer each sample filter
with forceps from its filter cassette unit to a
clean, separate 125-mL Phillips beaker along
with any loose dust found in the cassette.
Label each Phillips beaker with the appropriate sample number.
3.9.2. Digest the sample by adding 5 mL of
concentrated nitric acid (HNO3) to each Phillips beaker containing an air filter sample.
Place the Phillips beakers on a hot plate in
an exhaust hood and heat the samples until
approximately 0.5 mL remains. The sample
169
§ 1910.1027
solution in each Phillips beaker should become clear. If it is not clear, digest the sample with another portion of concentrated nitric acid.
3.9.3. After completing the HNO3 digestion
and cooling the samples, add 40 µ L (2 drops)
of concentrated HCl to each air sample solution and then swirl the contents. Carefully
add about 5 mL of deionized water by pouring it down the inside of each beaker.
3.9.4. Quantitatively transfer each cooled
air sample solution from each Phillips beaker to a clean 10-mL volumetric flask. Dilute
each flask to volume with deionized water
and mix well.
3.10. Flame AAS Analysis
Analyze all of the air samples for their
cadmium content by flame atomic absorption spectroscopy (AAS) according to the instructions given below.
3.10.1. Set up the atomic absorption spectrophotometer for the air/acetylene flame
analysis of cadmium according to the SOP
(5.8.) or the manufacturer’s operational instructions. For the source lamp, use the cadmium hollow cathode or electrodeless discharge lamp operated at the manufacturer’s
recommended rating for continuous operation. Allow the lamp to warm up 10 to 20
min or until the energy output stabilizes.
Optimize conditions such as lamp position,
burner head alignment, fuel and oxidant flow
rates, etc. See the SOP or specific instrument manuals for details. Instrumental parameters for the Perkin-Elmer Model 603
used in the validation of this method are
given in Attachment 1.
3.10.2. Aspirate and measure the absorbance of a standard solution of cadmium. The
standard concentration should be within the
linear range. For the instrumentation used
in the validation of this method a 2 µg/mL
cadmium standard gives a net absorbance
reading of about 0.350 abs. units (see Section
1.5.5.) when the instrument and the source
lamp are performing to manufacturer specifications.
3.10.3. To increase instrument response,
scale expand the absorbance reading of the
aspirated 2 µg/mL working standard approximately four times. Increase the integration
time to at least 3 seconds to reduce signal
noise.
3.10.4. Autozero the instrument while aspirating a deionized water blank. Monitor the
variation in the baseline absorbance reading
(baseline noise) for a few minutes to insure
that the instrument, source lamp and associated equipment are in good operating condition.
3.10.5. Aspirate the working standards and
samples directly into the flame and record
their absorbance readings. Aspirate the deionized water blank immediately after every
standard or sample to correct for and monitor any baseline drift and noise. Record the
baseline absorbance reading of each deionized water blank. Label each standard and
sample reading and its accompanying baseline reading.
3.10.6. It is recommended that the entire
series of working standards be analyzed at
the beginning and end of the analysis of a set
of samples to establish a concentration-response curve, ensure that the standard readings agree with each other and are reproducible. Also, analyze a working standard after
every five or six samples to monitor the performance of the spectrophotometer. Standard readings should agree within ±10 to 15%
of the readings obtained at the beginning of
the analysis.
3.10.7. Bracket the sample readings with
standards during the analysis. If the absorbance reading of a sample is above the absorbance reading of the highest working standard, dilute the sample with diluting solution
and reanalyze. Use the appropriate dilution
factor in the calculations.
3.10.8. Repeat the analysis of approximately 10% of the samples for a check of precision.
3.10.9. If possible, analyze quality control
samples from an independent source as a
check on analytical recovery and precision.
3.10.10. Record the final instrument settings at the end of the analysis. Date and
label the output.
3.11. AAS–HGA Analysis
Initially analyze all of the air samples for
their cadmium content by flame atomic absorption spectroscopy (AAS) according to
the instructions given in Section 3.10. If the
concentration of cadmium in a sample solution is less than three times the quantitative
detection limit [0.04 µg/mL (40 ng/mL) for the
instrumentation used in the validation] and
the sample results are to be averaged with
other samples for TWA calculations, proceed
with the AAS–HGA analysis of the sample as
described below.
3.11.1. Set up the atomic absorption spectrophotometer and HGA for flameless atomic
absorption analysis of cadmium according to
the SOP (5.9.) or the manufacturer’s operational instructions and allow the instrument to stabilize. The graphite furnace atomizer is equipped with a pyrolytically coated graphite tube containing a pyrolytic platform. For the source lamp, use a cadmium
hollow cathode or electrodeless discharge
lamp operated at the manufacturer’s recommended setting for graphite furnace operation. The Zeeman background corrector and
EDL are recommended for use with the L’vov
platform. Instrumental parameters for the
Perkin-Elmer Model 5100 spectrophotometer
and Zeeman HGA–600 graphite furnace used
in the validation of this method are given in
Attachment 2.
3.11.2. Optimize the energy reading of the
spectrophotometer at 228.8 nm by adjusting
170
the lamp position and the wavelength according to the manufacturer’s instructions.
3.11.3. Set up the autosampler to inject a 5µ L aliquot of the working standard, sample
or reagent blank solution onto the L’vov
platform along with a 10-µ L overlay of the
matrix modifier.
3.11.4. Analyze the reagent blank (diluting
solution, Section 3.5.6.) and then autozero
the instrument before starting the analysis
of a set of samples. It is recommended that
the reagent blank be analyzed several times
during the analysis to assure the integrated
absorbance (peak area) reading remains at or
near zero.
3.11.5. Analyze a working standard approximately midway in the linear portion of the
working standard range two or three times
to check for reproducibility and sensitivity
(see sections 1.5.5. and 1.5.6.) before starting
the analysis of samples. Calculate the experimental characteristic mass value from the
average integrated absorbance reading and
injection volume of the analyzed working
standard. Compare this value to the manufacturer’s suggested value as a check of proper instrument operation.
3.11.6. Analyze the reagent blank, working
standard, and sample solutions. Record and
label the peak area (abs-sec) readings and
the peak and background peak profiles on
the printer/plotter.
3.11.7. It is recommended the entire series
of working standards be analyzed at the beginning and end of the analysis of a set of
samples. Establish a concentration-response
curve and ensure standard readings agree
with each other and are reproducible. Also,
analyze a working standard after every five
or six samples to monitor the performance of
the system. Standard readings should agree
within ±15% of the readings obtained at the
beginning of the analysis.
3.11.8. Bracket the sample readings with
standards during the analysis. If the peak
area reading of a sample is above the peak
area reading of the highest working standard, dilute the sample with the diluting solution and reanalyze. Use the appropriate dilution factor in the calculations.
3.11.9. Repeat the analysis of approximately 10% of the samples for a check of precision.
3.11.10. If possible, analyze quality control
samples from an independent source as a
check of analytical recovery and precision.
3.11.11. Record the final instrument settings at the end of the analysis. Date and
label the output.
3.12. Calculations
NOTE: Standards used for HGA analysis are
in ng/mL. Total amounts of cadmium from
calculations will be in ng (not µg) unless a
prior conversion is made.
3.12.1. Correct for baseline drift and noise
in flame AAS analysis by subtracting each
§ 1910.1027
baseline absorbance reading from its corresponding working standard or sample absorbance reading to obtain the net absorbance reading for each standard and sample.
3.12.2. Use a least squares regression program to plot a concentration-response curve
of net absorbance reading (or peak area for
HGA analysis) versus concentration (µg/mL
or ng/mL) of cadmium in each working
standard.
3.12.3. Determine the concentration (µg/mL
or ng/mL) of cadmium in each sample from
the resulting concentration-response curve.
If the concentration of cadmium in a sample
solution is less than three times the quantitative detection limit [0.04 µg/mL (40 ng/
mL) for the instrumentation used in the validation of the method] and if consecutive
samples were taken on one employee and the
sample results are to be averaged with other
samples to determine a single TWA, reanalyze the sample by AAS–HGA as described in
Section 3.11. and report the AAS–HGA analytical results.
3.12.4. Calculate the total amount (µg or
ng) of cadmium in each sample from the
sample solution volume (mL):
W = (C)(sample vol, mL)(DF)
Where:
W = Total cadmium in sample
C = Calculated concentration of cadmium
DF = Dilution Factor (if applicable)
3.12.5. Make a blank correction for each air
sample by subtracting the total amount of
cadmium in the corresponding blank sample
from the total amount of cadmium in the
sample.
3.12.6. Calculate the concentration of cadmium in an air sample (mg/m3 or µg/m3) by
using one of the following equations:
mg/m3 = Wbc/(Air vol sampled, L)
or
µg/m3 = (Wbc)(1,000 ng/µg)/(Air vol sampled, L)
Where:
Wbc = blank corrected total µg cadmium in
the sample. (1µg=1,000 ng)
4. BACKUP DATA
4.1. Introduction
4.1.1. The purpose of this evaluation is to
determine the analytical method recovery,
working standard range, and qualitative and
quantitative detection limits of the two
atomic absorption analytical techniques included in this method. The evaluation consisted of the following experiments:
1. An analysis of 24 samples (six samples
each at 0.1, 0.5, 1 and 2 times the TWA–PEL)
for the analytical method recovery study of
the flame AAS analytical technique.
2. An analysis of 18 samples (six samples
each at 0.5, 1 and 2 times the Action Level
TWA–PEL) for the analytical method recovery study of the AAS–HGA analytical technique.
171
§ 1910.1027
3. Multiple analyses of the reagent blank
and a series of standard solutions to determine the working standard range and the
qualitative and quantitative detection limits
for both atomic absorption analytical techniques.
4.1.2. The analytical method recovery results at all test levels were calculated from
concentration-response curves and statistically examined for outliers at the 99% confidence level. Possible outliers were determined using the Treatment of Outliers test
(5.10.). In addition, the sample results of the
two analytical techniques, at 0.5, 1.0 and 2.0
times their target concentrations, were tested for homogeneity of variances also at the
99% confidence level. Homogeneity of the coefficients of variation was determined using
the Bartlett’s test (5.11.). The overall analytical error (OAE) at the 95% confidence level
was calculated using the equation (5.12.):
OAE = ±[| Bias|+(1.96)(CV1(pooled))(100%)]
4.1.3. A derivation of the International
Union of Pure and Applied Chemistry
(IUPAC) detection limit equation (5.13.) was
used to determine the qualitative and quantitative detection limits for both atomic absorption analytical techniques:
(Equation 1)
Cld = k(sd)/m
Where:
Cld = the smallest reliable detectable concentration an analytical instrument can
determine at a given confidence level.
k = 3 for the Qualitative Detection Limit at
the 99.86% Confidence Level
= 10 for the Quantitative Detection Limit at
the 99.99% Confidence Level.
sd = standard deviation of the reagent blank
(Rbl) readings.
m = analytical sensitivity or slope as calculated by linear regression.
4.1.4. Collection efficiencies of metallic
fume and dust atmospheres on 0.8-µ m mixed
cellulose ester membrane filters are well
documented and have been shown to be excellent (5.11.). Since elemental cadmium and
the cadmium component of cadmium compounds are nonvolatile, stability studies of
cadmium spiked MCEF samples were not
performed.
4.2. Equipment
4.2.1. A Perkin-Elmer (PE) Model 603 spectrophotometer equipped with a manual gas
control system, a stainless steel nebulizer, a
burner mixing chamber, a flow spoiler and a
10 cm. (one-slot) burner head was used in the
experimental validation of the flame AAS
analytical technique. A PE cadmium hollow
cathode lamp, operated at the manufacturer’s recommended current setting for continuous operation (4 mA), was used as the
source lamp. Instrument parameters are listed in Attachment 1.
4.2.2. A PE Model 5100 spectrophotometer,
Zeeman HGA–600 graphite furnace atomizer
and AS–60 HGA autosampler were used in the
experimental validation of the AAS–HGA analytical technique. The spectrophotometer
was equipped with a PE Series 7700 professional computer and Model PR–310 printer. A
PE System 2 cadmium electrodeless discharge lamp, operated at the manufacturer’s
recommended current setting for modulated
operation (170 mA), was used as the source
lamp. Instrument parameters are listed in
Attachment 2.
4.3. Reagents
4.3.1. J.T. Baker Chem. Co. (Analyzed
grade) concentrated nitric acid, 69.0–71.0%,
and concentrated hydrochloric acid, 36.5–
38.0%, were used to prepare the samples and
standards.
4.3.2. Ammonium phosphate, monobasic,
NH4 H2 PO4 and magnesium nitrate,
Mg(NO3)26H2 O, both manufactured by the
Mallinckrodt Chem. Co., were used to prepare the matrix modifier for AAS–HGA analysis.
4.4. Standard Preparation for Flame AAS
Analysis
4.4.1. Dilute stock solutions: Prepared 0.01,
0.1, 1, 10 and 100 µg/mL cadmium standard
stock solutions by making appropriate serial
dilutions of a commercially available 1,000
µg/mL cadmium standard stock solution
(RICCA Chemical Co., Lot# A102) with the
diluting solution (4% HNO3, 0.4% HCl).
4.4.2. Analyzed Standards: Prepared cadmium standards in the range of 0.001 to 2.0
µg/mL by pipetting 2 to 10 mL of the appropriate dilute cadmium stock solution into a
100-mL volumetric flask and diluting to volume with the diluting solution. (See Section
3.7.2.)
4.5. Standard Preparation for AAS–HGA
Analysis
4.5.1. Dilute stock solutions: Prepared 1, 10,
100 and 1,000 ng/mL cadmium standard stock
solutions by making appropriate serial dilutions of a commercially available 1,000 µg/mL
cadmium standard stock solution (J.T.
Baker Chemical Co., Instra-analyzed, Lot#
D22642) with the diluting solution (4% HNO3,
0.4% HCl).
4.5.2. Analyzed Standards: Prepared cadmium standards in the range of 0.1 to 40 ng/
mL by pipetting 2 to 10 mL of the appropriate dilute cadmium stock solution into a
100-mL volumetric flask and diluting to volume with the diluting solution. (See Section
3.8.2.)
4.6. Detection Limits and Standard Working
Range for Flame AAS Analysis
4.6.1. Analyzed the reagent blank solution
and the entire series of cadmium standards
in the range of 0.001 to 2.0 µg/mL three to six
times according to the instructions given in
172
Section 3.10. The diluting solution (4% HNO3,
0.4% HCl) was used as the reagent blank. The
integration time on the PE 603 spectrophotometer was set to 3.0 seconds and a fourfold expansion of the absorbance reading of
the 2.0 µg/mL cadmium standard was made
prior to analysis. The 2.0 µg/mL standard
gave a net absorbance reading of 0.350 abs.
units prior to expansion in agreement with
the manufacturer’s specifications (5.6.).
4.6.2. The net absorbance readings of the
reagent blank and the low concentration Cd
standards from 0.001 to 0.1 µg/mL and the statistical analysis of the results are shown in
Table I. The standard deviation, sd, of the
six net absorbance readings of the reagent
blank is 1.05 abs. units. The slope, m, as calculated by a linear regression plot of the net
absorbance readings (shown in Table II) of
the 0.02 to 1.0 µg/mL cadmium standards
versus their concentration is 772.7 abs. units/
(µg/mL).
4.6.3. If these values for sd and the slope,
m, are used in Eqn. 1 (Sect. 4.1.3.), the qualitative and quantitative detection limits as
determined by the IUPAC Method are:
Cld=(3)(1.05 abs. units)/(772.7 abs. units/(µg/
mL))
= 0.0041 µg/mL for the qualitative detection
limit.
Cld=(10)(1.05 abs. units)/(772.7 abs. units/µg/
mL))
=0.014 µg/mL for the quantitative detection
limit.
The qualitative and quantitative detection
limits for the flame AAS analytical technique are 0.041 µg and 0.14 µg cadmium, respectively, for a 10 mL solution volume.
These correspond, respectively, to 0.2 µg/m3
and 0.70 µg/m3 for a 200 L air volume.
4.6.4. The recommended Cd standard working range for flame AAS analysis is 0.02 to
2.0 µg/mL. The net absorbance readings of
the reagent blank and the recommended
working range standards and the statistical
analysis of the results are shown in Table II.
The standard of lowest concentration in the
working range, 0.02 µg/mL, is slightly greater
than the calculated quantitative detection
limit, 0.014 µg/mL. The standard of highest
concentration in the working range, 2.0 µg/
mL, is at the upper end of the linear working
range suggested by the manufacturer (5.6.).
Although the standard net absorbance readings are not strictly linear at concentrations
above 0.5 µg/mL, the deviation from linearity
is only about 10% at the upper end of the recommended standard working range. The deviation from linearity is probably caused by
the four-fold expansion of the signal suggested in the method. As shown in Table II,
the precision of the standard net absorbance
readings are excellent throughout the recommended working range; the relative
standard deviations of the readings range
from 0.009 to 0.064.
§ 1910.1027
4.7. Detection Limits and Standard
Working Range for AAS–HGA Analysis
4.7.1. Analyzed the reagent blank solution
and the entire series of cadmium standards
in the range of 0.1 to 40 ng/mL according to
the instructions given in Section 3.11. The
diluting solution (4% HNO3, 0.4% HCl) was
used as the reagent blank. A fresh aliquot of
the reagent blank and of each standard was
used for every analysis. The experimental
characteristic mass value was 0.41 pg, calculated from the average peak area (abs-sec)
reading of the 5 ng/mL standard which is approximately midway in the linear portion of
the working standard range. This agreed
within 20% with the characteristic mass
value, 0.35 pg, listed by the manufacturer of
the instrument (5.2.).
4.7.2. The peak area (abs-sec) readings of
the reagent blank and the low concentration
Cd standards from 0.1 to 2.0 ng/mL and statistical analysis of the results are shown in
Table III. Five of the reagent blank peak
area readings were zero and the sixth reading
was 1 and was an outlier. The near lack of a
blank signal does not satisfy a strict interpretation of the IUPAC method for determining the detection limits. Therefore, the
standard deviation of the six peak area readings of the 0.2 ng/mL cadmium standard, 0.75
abs-sec, was used to calculate the detection
limits by the IUPAC method. The slope, m,
as calculated by a linear regression plot of
the peak area (abs-sec) readings (shown in
Table IV) of the 0.2 to 10 ng/mL cadmium
standards versus their concentration is 51.5
abs-sec/(ng/mL).
4.7.3. If 0.75 abs-sec (sd) and 51.5 abs-sec/(ng/
mL) (m) are used in Eqn. 1 (Sect. 4.1.3.), the
qualitative and quantitative detection limits
as determined by the IUPAC method are:
Cld = (3)(0.75 abs-sec)/(51.5 abs-sec/(ng/mL)
= 0.044 ng/mL for the qualitative detection
limit.
Cld= (10)(0.75 abs-sec)/(51.5 abs-sec/(ng/mL) =
0.15 ng/mL for the quantitative detection
limit.
The qualitative and quantitative detection
limits for the AAS-HGA analytical technique
are 0.44 ng and 1.5 ng cadmium, respectively,
for a 10 mL solution volume. These correspond, respectively, to 0.007 µg/m3 and 0.025
µg/m3 for a 60 L air volume.
4.7.4. The peak area (abs-sec) readings of
the Cd standards from 0.2 to 40 ng/mL and
the statistical analysis of the results are
given in Table IV. The recommended standard working range for AAS-HGA analysis is
0.2 to 20 ng/mL. The standard of lowest concentration in the recommended working
range is slightly greater than the calculated
quantitative detection limit, 0.15 ng/mL. The
deviation from linearity of the peak area
readings of the 20 ng/mL standard, the highest concentration standard in the recommended working range, is approximately
173
§ 1910.1027
10%. The deviations from linearity of the
peak area readings of the 30 and 40 ng/mL
standards are significantly greater than 10%.
As shown in Table IV, the precision of the
peak area readings are satisfactory throughout the recommended working range; the relative standard deviations of the readings
range from 0.025 to 0.083.
4.8. Analytical Method Recovery for Flame
AAS Analysis
4.8.1. Four sets of spiked MCEF samples
were prepared by injecting 20 µL of 10, 50, 100
and 200 µg/mL dilute cadmium stock solutions on 37 mm diameter filters (part no.
AAWP 037 00, Millipore Corp., Bedford, MA)
with a calibrated micropipet. The dilute
stock solutions were prepared by making appropriate serial dilutions of a commercially
available 1,000 µg/mL cadmium standard
stock solution (RICCA Chemical Co., Lot#
A102) with the diluting solution (4% HNO3,
0.4% HCl). Each set contained six samples
and a sample blank. The amount of cadmium
in the prepared sets were equivalent to 0.1,
0.5, 1.0 and 2.0 times the TWA PEL target
concentration of 5 µg/m3 for a 400 L air volume.
4.8.2. The air-dried spiked filters were digested and analyzed for their cadmium content by flame atomic absorption spectroscopy (AAS) following the procedure described in Section 3. The 0.02 to 2.0µg/mL
cadmium standards (the suggested working
range) were used in the analysis of the
spiked filters.
4.8.3. The results of the analysis are given
in Table V. One result at 0.5 times the TWA
PEL target concentration was an outlier and
was excluded from statistical analysis. Experimental justification for rejecting it is
that the outlier value was probably due to a
spiking error. The coefficients of variation
for the three test levels at 0.5 to 2.0 times the
TWA PEL target concentration passed the
Bartlett’s test and were pooled.
4.8.4. The average recovery of the six
spiked filter samples at 0.1 times the TWA
PEL target concentration was 118.2% with a
coefficient of variation (CV1) of 0.128. The average recovery of the spiked filter samples in
the range of 0.5 to 2.0 times the TWA target
concentration was 104.0% with a pooled coefficient of variation (CV1) of 0.010. Consequently, the analytical bias found in these
spiked sample results over the tested concentration range was +4.0% and the OAE was
±6.0%.
4.9. Analytical Method Recovery for AASHGA Analysis
4.9.1. Three sets of spiked MCEF samples
were prepared by injecting 15µ L of 5, 10 and
20 µg/mL dilute cadmium stock solutions on
37 mm diameter filters (part no. AAWP 037
00, Millipore Corp., Bedford, MA) with a cali-
brated micropipet. The dilute stock solutions were prepared by making appropriate
serial dilutions of a commercially available
certified 1,000 µg/mL cadmium standard
stock solution (Fisher Chemical Co., Lot#
913438–24) with the diluting solution (4%
HNO3, 0.4% HCl). Each set contained six samples and a sample blank. The amount of cadmium in the prepared sets were equivalent to
0.5, 1 and 2 times the Action Level TWA target concentration of 2.5 µg/m3 for a 60 L air
volume.
4.9.2. The air-dried spiked filters were digested and analyzed for their cadmium content by flameless atomic absorption spectroscopy using a heated graphite furnace atomizer following the procedure described in
Section 3. A five-fold dilution of the spiked
filter samples at 2 times the Action Level
TWA was made prior to their analysis. The
0.05 to 20 ng/mL cadmium standards were
used in the analysis of the spiked filters.
4.9.3. The results of the analysis are given
in Table VI. There were no outliers. The coefficients of variation for the three test levels at 0.5 to 2.0 times the Action Level TWA
PEL passed the Bartlett’s test and were
pooled. The average recovery of the spiked
filter samples was 94.2% with a pooled coefficient of variation (CV1) of 0.043. Consequently, the analytical bias was ¥5.8% and
the OAE was ±14.2%.
4.10. Conclusions
The experiments performed in this evaluation show the two atomic absorption analytical techniques included in this method to be
precise and accurate and have sufficient sensitivity to measure airborne cadmium over a
broad range of exposure levels and sampling
periods.
5. REFERENCES
5.1. Slavin, W. Graphite Furnace AAS—A
Source Book; Perkin-Elmer Corp., Spectroscopy Div.: Ridgefield, CT, 1984; p. 18 and pp.
83–90.
5.2. Grosser, Z., Ed.; Techniques in Graphite
Furnace
Atomic
Absorption
Spectrophotometry; Perkin-Elmer Corp.,
Spectroscopy Div.: Ridgefield, CT, 1985.
5.3. Occupational Safety and Health Administration Salt Lake Technical Center:
Metal and Metalloid Particulate in Workplace Atmospheres (Atomic Absorption)
(USDOL/OSHA Method No. ID–121). In OSHA
Analytical Methods Manual 2nd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, 1991.
Metal and Metalloid Particulate in Workplace Atmospheres (ICP) (USDOL/OSHA
Method No. ID–125G). In OSHA Analytical
Methods Manual 2nd ed. Cincinnati, OH:
174
American Conference of Governmental Industrial Hygienists, 1991.
5.5. Windholz, M., Ed.; The Merck Index,
10th ed.; Merck & Co.: Rahway, NJ, 1983.
5.6. Analytical Methods for Atomic Absorption Spectrophotometry, The Perkin-Elmer
Corporation: Norwalk, CT, 1982.
5.7. Slavin, W., D.C. Manning, G. Carnrick,
and E. Pruszkowska: Properties of the Cadmium Determination with the Platform Furnace and Zeeman Background Correction.
Spectrochim. Acta 38B:1157–1170 (1983).
Standard Operating Procedure for Atomic
Absorption. Salt Lake City, UT: USDOL/
OSHA-SLTC, In progress.
AAS-HGA Standard Operating Procedure.
Salt Lake City, UT: USDOL/OSHA-SLTC, In
progress.
5.10. Mandel, J.: Accuracy and Precision,
Evaluation and Interpretation of Analytical
Results, The Treatment of Outliers. In Treatise On Analytical Chemistry, 2nd ed., Vol.1,
edited by I. M. Kolthoff and P. J. Elving.
New York: John Wiley and Sons, 1978. pp.
282–285.
5.11. National Institute for Occupational
Safety and Health: Documentation of the
NIOSH Validation Tests by D. Taylor, R.
Kupel, and J. Bryant (DHEW/NIOSH Pub. No.
77–185). Cincinnati, OH: National Institute
for Occupational Safety and Health, 1977.
5.12. Occupational Safety and Health Administration Analytical Laboratory: Precision and Accuracy Data Protocol for Laboratory Validations. In OSHA Analytical Methods Manual 1st ed. Cincinnati, OH: American
Conference of Governmental Industrial Hygienists (Pub. No. ISBN: 0–936712–66–X), 1985.
5.13. Long, G.L. and J.D. Winefordner:
Limit of Detection—A Closer Look at the
IUPAC Definition. Anal.Chem. 55:712A–724A
(1983).
5.14. American Conference of Governmental Industrial Hygienists: Documentation of Threshold Limit Values and Biological Exposure Indices. 5th ed. Cincinnati, OH:
American Conference of Governmental Industrial Hygienists, 1986.
§ 1910.1027
TABLE I—CD DETECTION LIMIT STUDY—
Continued
[Flame AAS Analysis]
STD (µg/mL)
Absorbance reading at 228.8 nm
0.002 .....................
5
7
7
7
3
4
0.005 .....................
7
8
8
7
8
6
0.010 .....................
10
10
10
9
13
10
0.020 .....................
20
20
20
23
22
20
0.050 .....................
42
42
42
42
42
45
0.10 .......................
84
80
83
STD (µg/mL)
Reagent blank ......
5
4
4
2
3
3
STD (µg/mL)
Reagent blank ......
5
4
4
2
3
3
0.020 .....................
20
20
20
23
22
20
0.050 .....................
42
42
42
42
42
45
0.10 .......................
84
80
83
0.20 .......................
161
161
158
0.50 .......................
391
389
393
1.00 .......................
760
748
752
0.001 .....................
6
2
6
6
4
6
2.00 .......................
1416
1426
1401
Statistical analysis
n=6.
mean=3.50.
std dev=1.05.
CV=0.30.
n=6.
mean=5.00.
std dev=1.67.
CV=0.335.
n=6.
mean=5.50.
std dev=1.76.
CV=0.320.
n=6.
mean=7.33.
std dev=0.817.
CV=0.111.
n=6.
mean=10.3.
std dev=1.37.
CV=0.133.
n=6.
mean=20.8.
std dev=1.33.
CV=0.064.
n=6.
mean=42.5.
std dev=1.22.
CV=0.029.
n=3.
mean=82.3.
std dev=2.08.
CV=0.025.
TABLE II—CD STANDARD WORKING RANGE
STUDY
TABLE I—CD DETECTION LIMIT STUDY
175
n=6.
mean=3.50.
std dev=1.05.
CV=0.30.
n=6.
mean=20.8.
std dev=1.33.
CV=0.064.
n=6.
mean=42.5.
std dev=1.22.
CV=0.029.
n=3.
mean=82.3.
std dev=2.08.
CV=0.025.
n=3.
mean=160.0.
std dev=1.73.
CV=0.011.
n=3.
mean=391.0.
std dev=2.00.
CV=0.005.
n=3.
mean=753.3.
std dev=6.11.
CV=0.008.
n=3.
mean=1414.3.
std dev=12.6.
CV=0.009.
§ 1910.1027
TABLE III—CD DETECTION LIMIT STUDY
TABLE IV—CD STANDARD WORKING RANGE
STUDY
[AAS–HGA Analysis]
[AAS-HGA Analysis]
STD (ng/mL)
Reagent blank ...........
Peak area
readings ×
10 3 at
228.8 nm
STD (ng/mL)
0
0
0
0
1
0
8
5
13
6
7
7
11
11
12
13
12
12
0.5 .............................
28
26
28
33
28
30
1.0 .............................
52
56
54
55
58
54
2.0 .............................
101
110
110
112
110
110
0.1 .............................
0.2 .............................
Peak area
readings ×
10 3 at
228.8 nm
n=6.
mean=0.167.
std dev=0.41.
CV=2.45.
n=6.
mean=7.7.
std dev=2.8.
CV=0.366.
n=6.
mean=11.8.
std dev=0.75.
CV=0.064.
n=6.
mean=28.8.
std dev=2.4.
CV=0.083.
n=6.
mean=54.8.
std dev=2.0.
CV=0.037.
n=6.
mean=108.8.
std dev=3.9.
CV=0.036.
0.2 .............................
11
11
12
13
12
12
0.5 .............................
28
26
28
33
28
30
1.0 .............................
52
56
54
55
58
54
2.0 .............................
101
110
110
112
110
110
5.0 .............................
247
268
259
265
275
279
10.0 ...........................
495
523
516
520
513
533
20.0 ...........................
950
951
949
953
958
890
30.0 ...........................
1269 1291
1303 1307
1295 1290
40.0 ...........................
1505 1567
1535 1567
1566 1572
n=6.
mean=11.8.
std dev=0.75.
CV=0.064.
n=6.
mean=28.8.
std dev=2.4.
CV=0.083.
n=6.
mean=54.8.
std dev=2.0.
CV=0.037.
n=6.
mean=108.8.
std dev=3.9.
CV=0.036.
n=6.
mean=265.5.
std dev=11.5.
CV=0.044.
n=6.
mean=516.7.
std dev=12.7.
CV=0.025.
n=6.
mean=941.8.
std dev=25.6.
CV=0.027.
n=6.
mean=1293.
std dev=13.3.
CV=0.010.
n=6.
mean=1552.
std dev=26.6.
CV=0.017.
TABLE V—ANALYTICAL METHOD RECOVERY
1.00
1.00
1.00
1.00
1.00
1.00
Test level
0.5×
µg taken
µg found
...................................................
...................................................
...................................................
...................................................
...................................................
...................................................
n=
mean=
std dev=
CV1=
1.0715
1.0842
1.0842
*1.0081
1.0715
1.0842
Percent
rec.
107.2
108.4
108.4
*100.8
107.2
108.4
µg
taken
1.0×
µg found
2.00
2.00
2.00
2.00
2.00
2.00
5
107.9
0.657
0.006
CV1 (pooled)=0.010
2.0688
2.0174
2.0431
2.0431
2.0174
2.0045
Percent
rec.
103.4
100.9
102.2
102.2
100.9
100.2
6
101.6
1.174
0.011
* Rejected as an outlier—this value did not pass the outlier T-test at the 99% confidence level.
176
µg
taken
4.00
4.00
4.00
4.00
4.00
4.00
2.0×
µg found
4.1504
4.1108
4.0581
4.0844
4.1504
4.1899
Percent
rec.
103.8
102.8
101.5
102.1
103.8
104.7
6
103.1
1.199
0.012
0.200
0.200
0.200
0.200
0.200
0.200
§ 1910.1027
Test level
0.1×
µg taken
µg found
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Percent rec.
0.2509
0.2509
0.2761
0.2258
0.2258
0.1881
125.5
125.5
138.1
112.9
112.9
94.1
n= .........................................................................................................................................
mean= ..................................................................................................................................
std dev= ...............................................................................................................................
CV1= ....................................................................................................................................
6
118.2
15.1
0.128
TABLE VI—ANALYTICAL METHOD RECOVERY
[AAS–HGA analysis]
75
75
75
75
75
75
Test level
0.5×
ng taken
ng
found
.................................................................
.................................................................
.................................................................
.................................................................
.................................................................
.................................................................
n=
mean=
std dev=
CV1=
1.0×
Percent
rec.
71.23
71.47
70.02
77.34
78.32
71.96
95.0
95.3
93.4
103.1
104.4
95.9
ng
taken
ng found
150
150
150
150
150
150
138.00
138.29
136.30
146.62
145.17
144.88
2.0×
Percent
rec.
ng
taken
ng found
300
300
300
300
300
300
258.43
258.46
280.55
288.34
261.74
277.22
92.0
92.2
90.9
97.7
96.8
96.6
6
97.9
4.66
0.048
CV1(pooled)=0.043
Percent
rec.
86.1
86.2
93.5
96.1
87.2
92.4
6
94.4
2.98
0.032
6
90.3
4.30
0.048
ATTACHMENT 1
ATTACHMENT 2
Instrumental Parameters for Flame AAS
Analysis
Instrumental Parameters for HGA Analysis
Atomic Absorption Spectrophotometer
(Perkin-Elmer Model 5100)
Atomic Absorption Spectrophotometer
(Perkin-Elmer Model 603)
Flame: Air/Acetylene—lean, blue
Oxidant Flow: 55
Fuel Flow: 32
Wavelength: 228.8 nm
Slit: 4 (0.7 nm)
Range: UV
Signal: Concentration (4 exp)
Integration Time: 3 sec
Signal Type: Zeeman AA
Slitwidth: 0.7 nm
Wavelength: 228.8 nm
Measurement: Peak Area
Integration Time: 6.0 sec
BOC Time: 5 sec
BOC=Background Offset Correction.
ZEEMAN GRAPHITE FURNACE (PERKIN-ELMER MODEL HGA–600)
Step
1)
2)
3)
4)
5)
6)
Ramp time
(sec)
Predry .................................................................................
Dry ......................................................................................
Char ....................................................................................
Cool Down ..........................................................................
Atomize ...............................................................................
Burnout ...............................................................................
5
30
10
1
0
1
177
Hold time
(sec)
10
10
20
8
5
8
Temp. (°
C)
90
140
900
30
1600
2500
Argon flow
(mL/min)
Read (sec)
300
300
300
300
0
300
..................
..................
..................
..................
¥1
..................
§ 1910.1027
APPENDIX F TO § 1910.1027—NONMANDATORY PROTOCOL FOR BIOLOGICAL
MONITORING
1.00
Introduction
Under the final OSHA cadmium rule (29
CFR part 1910), monitoring of biological
specimens and several periodic medical examinations are required for eligible employees. These medical examinations are to be
conducted regularly, and medical monitoring
is to include the periodic analysis of cadmium in blood (CDB), cadmium in urine
(CDU) and beta-2-microglobulin in urine
(B2MU). As CDU and B2MU are to be normalized to the concentration of creatinine in
urine (CRTU), then CRTU must be analyzed
in conjunction with CDU and B2MU analyses.
The purpose of this protocol is to provide
procedures for establishing and maintaining
the quality of the results obtained from the
analyses of CDB, CDU and B2MU by commercial laboratories. Laboratories conforming
to the provisions of this nonmandatory protocol shall be known as ‘‘participating laboratories.’’ The biological monitoring data
from these laboratories will be evaluated by
physicians responsible for biological monitoring to determine the conditions under
which employees may continue to work in
locations exhibiting airborne-cadmium concentrations at or above defined actions levels (see paragraphs (l)(3) and (l)(4) of the
final rule). These results also may be used to
support a decision to remove workers from
such locations.
Under the medical monitoring program for
cadmium, blood and urine samples must be
collected at defined intervals from workers
by physicians responsible for medical monitoring; these samples are sent to commerical
laboratories that perform the required analyses and report results of these analyses to
the responsible physicians. To ensure the accuracy and reliability of these laboratory
analyses, the laboratories to which samples
are submitted should participate in an ongoing and efficacious proficiency testing program. Availability of proficiency testing programs may vary with the analyses performed.
To test proficiency in the analysis of CDB,
CDU and B2MU, a laboratory should participate either in the interlaboratory comparison program operated by the Centre de
Toxicologie du Quebec (CTQ) or an equivalent program. (Currently, no laboratory in
the U.S. performs proficiency testing on
CDB, CDU or B2MU.) Under this program,
CTQ sends participating laboratories 18 samples of each analyte (CDB, CDU and/or
B2MU) annually for analysis. Participating
laboratories must return the results of these
analyses to CTQ within four to five weeks
after receiving the samples.
The CTQ program pools analytical results
from many participating laboratories to derive consensus mean values for each of the
samples distributed. Results reported by
each laboratory then are compared against
these consensus means for the analyzed samples to determine the relative performance
of each laboratory. The proficiency of a participating laboratory is a function of the extent of agreement between results submitted
by the participating laboratory and the consensus values for the set of samples analyzed.
Proficiency testing for CRTU analysis
(which should be performed with CDU and
B2MU analyses to evaluate the results properly) also is recommended. In the U.S., only
the College of American Pathologists (CAP)
currently conducts CRTU proficiency testing; participating laboratories should be accredited for CRTU analysis by the CAP.
Results of the proficiency evaluations will
be forwarded to the participating laboratory
by the proficiency-testing laboratory, as well
as to physicians designated by the participating laboratory to receive this information. In addition, the participating laboratory should, on request, submit the results of
their internal Quality Assurance/Quality
Control (QA/QC) program for each analytic
procedure (i.e., CDB, CDU and/or B2MU) to
physicians designated to receive the proficiency results. For participating laboratories offering CDU and/or B2MU analyses,
QA/QC documentation also should be provided for CRTU analysis. (Laboratories
should provide QA/QC information regarding
CRTU analysis directly to the requesting
physician if they perform the analysis inhouse; if CRTU analysis is performed by another laboratory under contract, this information should be provided to the physician
by the contract laboratory.)
QA/QC information, along with the actual
biological specimen measurements, should
be provided to the responsible physician
using standard formats. These physicians
then may collate the QA/QC information
with proficiency test results to compare the
relative performance of laboratories, as well
as to facilitate evaluation of the worker
monitoring data. This information supports
decisions made by the physician with regard
to the biological monitoring program, and
for mandating medical removal.
This protocol describes procedures that
may be used by the responsible physicians to
identify laboratories most likely to be proficient in the analysis of samples used in the
biological monitoring of cadmium; also provided are procedures for record keeping and
reporting by laboratories participating in
proficiency testing programs, and recommendations to assist these physicians in
interpreting analytical results determined
by participating laboratories. As the collection and handling of samples affects the
178
quality of the data, recommendations are
made for these tasks. Specifications for analytical methods to be used in the medical
monitoring program are included in this protocol as well.
In conclusion, this document is intended as
a supplement to characterize and maintain
the quality of medical monitoring data collected under the final cadmium rule promulgated by OSHA (29 CFR part 1910). OSHA has
been granted authority under the Occupational Safety and Health Act of 1970 to protect workers from the effects of exposure to
hazardous substances in the work place and
to mandate adequate monitoring of workers
to determine when adverse health effects
may be occurring. This nonmandatory protocol is intended to provide guidelines and
recommendations to improve the accuracy
and reliability of the procedures used to analyze the biological samples collected as part
of the medical monitoring program for cadmium.
2.0
Definitions
When the terms below appear in this protocol, use the following definitions.
Accuracy: A measure of the bias of a data
set. Bias is a systematic error that is either
inherent in a method or caused by some artifact or idiosyncracy of the measurement system. Bias is characterized by a consistent deviation (positive or negative) in the results
from an accepted reference value.
Arithmetic Mean: The sum of measurements
in a set divided by the number of measurements in a set.
Blind Samples: A quality control procedure
in which the concentration of analyte in the
samples should be unknown to the analyst at
the time that the analysis is performed.
Coefficient of Variation: The ratio of the
standard deviation of a set of measurements
to the mean (arithmetic or geometric) of the
measurements.
Compliance Samples: Samples from exposed
workers sent to a participating laboratory
for analysis.
Control Charts: Graphic representations of
the results for quality control samples being
analyzed by a participating laboratory.
Control Limits: Statistical limits which define when an analytic procedure exceeds acceptable parameters; control limits provide a
method of assessing the accuracy of analysts, laboratories, and discrete analytic
runs.
Control Samples: Quality control samples.
F/T: The measured amount of an analyte
divided by the theoretical value (defined
below) for that analyte in the sample analyzed; this ratio is a measure of the recovery
for a quality control sample.
Geometric Mean: The natural antilog of the
mean of a set of natural log-transformed
data.
§ 1910.1027
Geometric Standard Deviation: The antilog
of the standard deviation of a set of natural
log-transformed data.
Limit of Detection: Using a predefined level
of confidence, this is the lowest measured
value at which some of the measured material is likely to have come from the sample.
Mean: A central tendency of a set of data;
in this protocol, this mean is defined as the
arithmetic mean (see definition of arithmetic
mean above) unless stated otherwise.
Performance: A measure of the overall quality of data reported by a laboratory.
Pools: Groups of quality-control samples to
be established for each target value (defined
below) of an analyte. For the protocol provided in attachment 3, for example, the theoretical value of the quality control samples
of the pool must be within a range defined as
plus or minus (±) 50% of the target value.
Within each analyte pool, there must be
quality control samples of at least 4 theoretical values.
Precision: The extent of agreement between
repeated, independent measurements of the
same quantity of an analyte.
Proficiency: The ability to satisfy a specified level of analyte performance.
Proficiency Samples: Specimens, the values
of which are unknown to anyone at a participating laboratory, and which are submitted
by a participating laboratory for proficiency
testing.
Quality or Data Quality: A measure of the
confidence in the measurement value.
Quality Control (QC) Samples: Specimens,
the value of which is unknown to the analyst, but is known to the appropriate QA/QC
personnel of a participating laboratory;
when used as part of a laboratory QA/QC program, the theoretical values of these samples
should not be known to the analyst until the
analyses are complete. QC samples are to be
run in sets consisting of one QC sample from
each pool (see definition of ‘‘pools’’ above).
Sensitivity: For the purposes of this protocol, the limit of detection.
Standard Deviation: A measure of the distribution or spread of a data set about the
mean; the standard deviation is equal to the
positive square root of the variance, and is
expressed in the same units as the original
measurements in the data set.
Standards: Samples with values known by
the analyst and used to calibrate equipment
and to check calibration throughout an analytic run. In a laboratory QA/QC program,
the values of the standards must exceed the
values obtained for compliance samples such
that the lowest standard value is near the
limit of detection and the highest standard
is higher than the highest compliance sample or QC sample. Standards of at least three
different values are to be used for calibration, and should be constructed from at least
2 different sources.
179
§ 1910.1027
Target Value: Those values of CDB, CDU or
B2MU which trigger some action as prescribed in the medical surveillance section of
the regulatory text of the final cadmium
rule. For CDB, the target values are 5, 10 and
15 µg/l. For CDU, the target values are 3, 7,
and 15 µg/g CRTU. For B2 MU, the target values are 300, 750 and 1500 µg/g CRTU. (Note
that target values may vary as a function of
time.)
Theoretical Value (or Theoretical Amount):
The reported concentration of a quality-control sample (or calibration standard) derived
from prior characterizations of the sample.
Value or Measurement Value: The numerical
result of a measurement.
Variance: A measure of the distribution or
spread of a data set about the mean; the
variance is the sum of the squares of the differences between the mean and each discrete
measurement divided by one less than the
number of measurements in the data set.
3.0
Protocol
This protocol provides procedures for characterizing and maintaining the quality of
analytic results derived for the medical monitoring program mandated for workers under
the final cadmium rule.
3.1
Overview
The goal of this protocol is to assure that
medical monitoring data are of sufficient
quality to facilitate proper interpretation.
The data quality objectives (DQOs) defined
for the medical monitoring program are
summarized in Table 1. Based on available
information, the DQOs presented in Table 1
should be achievable by the majority of laboratories offering the required analyses commercially; OSHA recommends that only laboratories meeting these DQOs be used for the
analysis of biological samples collected for
monitoring cadmium exposure.
TABLE 1—RECOMMENDED DATA QUALITY OBJECTIVES (DQOS) FOR THE CADMIUM MEDICAL
MONITORING PROGRAM
Analyte/concentration pool
Limit of detection
Precision
(CV) (%)
Cadmium in blood ........................
≤2 µg/l ...................................
>2µg/l .....................................
Cadmium in urine .........................
≤2 µg/l creatinine ..................
>2µg/l creatinine ....................
β-2-microglobulin in urine: 100
µg/g creatine.
0.5 µg/l ........................................
......................................................
......................................................
0.5 µg/g creatinine ......................
......................................................
......................................................
100 µg/g creatinine .....................
....................
40
20
....................
40
20
5
To satisfy the DQOs presented in Table 1,
OSHA provides the following guidelines:
1. Procedures for the collection and handling of blood and urine are specified (Section 3.4.1 of this protocol);
2. Preferred analytic methods for the analysis of CDB, CDU and B2MU are defined (and
a method for the determination of CRTU
also is specified since CDU and B2MU results
are to be normalized to the level of CRTU).
3. Procedures are described for identifying
laboratories likely to provide the required
analyses in an accurate and reliable manner;
4. These guidelines (Sections 3.2.1 to 3.2.3,
and Section 3.3) include recommendations
regarding internal QA/QC programs for participating laboratories, as well as levels of
proficiency through participation in an
interlaboratory proficiency program;
5. Procedures for QA/QC record keeping
(Section 3.3.2), and for reporting QC/QA results are described (Section 3.3.3); and,
6. Procedures for interpreting medical
monitoring results are specified (Section
3.4.3).
Methods recommended for the biological
monitoring of eligible workers are:
Accuracy
±1 µg/l or 15% of the mean.
±1 µg/l or 15% of the mean.
±15% of the mean.
1. The method of Stoeppler and Brandt
(1980) for CDB determinations (limit of detection: 0.5 µg/l);
2. The method of Pruszkowska et al. (1983)
for CDU determinations (limit of detection:
0.5 µg/l of urine); and,
3. The Pharmacia Delphia test kit
(Pharmacia 1990) for the determination of
B2MU (limit of detection: 100 µg/l urine).
Because both CDU and B2MU should be reported in µg/g CRTU, an independent determination of CRTU is recommended. Thus,
both the OSHA Salt Lake City Technical
Center (OSLTC) method (OSHA, no date) and
the Jaffe method (Du Pont, no date) for the
determination of CRTU are specified under
this protocol (i.e., either of these 2 methods
may be used). Note that although detection
limits are not reported for either of these
CRTU methods, the range of measurements
expected for CRTU (0.9-1.7 µg/l) are well
above the likely limit of detection for either
of these methods (Harrison, 1987).
Laboratories using alternate methods
should submit sufficient data to the responsible physicians demonstrating that the alternate method is capable of satisfying the
180
defined data quality objectives of the program. Such laboratories also should submit a
QA/QC plan that documents the performance
of the alternate method in a manner entirely
equivalent to the QA/QC plans proposed in
Section 3.3.1.
3.2 Duties of the Responsible Physician
The responsible physician will evaluate biological monitoring results provided by participating laboratories to determine whether
such laboratories are proficient and have
satisfied the QA/QC recommendations. In determining which laboratories to employ for
this purpose, these physicians should review
proficiency and QA/QC data submitted to
them by the participating laboratories.
Participating laboratories should demonstrate proficiency for each analyte (CDU,
CDB and B2MU) sampled under the biological
monitoring program. Participating laboratories involved in analyzing CDU and B2MU
also should demonstrate proficiency for
CRTU analysis, or provide evidence of a contract with a laboratory proficient in CRTU
analysis.
3.2.1
Recommendations for Selecting
Among Existing Laboratories
OSHA recommends that existing laboratories providing commercial analyses for
CDB, CDU and/or B2MU for the medical monitoring program satisfy the following criteria:
1. Should have performed commercial analyses for the appropriate analyte (CDB, CDU
and/or B2MU) on a regular basis over the last
2 years;
2. Should provide the responsible physician
with an internal QA/QC plan;
3. If performing CDU or B2MU analyses,
the participating laboratory should be accredited by the CAP for CRTU analysis, and
should be enrolled in the corresponding CAP
survey (note that alternate credentials may
be acceptable, but acceptability is to be determined by the responsible physician); and,
4. Should have enrolled in the CTQ interlaboratory comparison program for the appropriate analyte (CDB, CDU and/or B2MU).
Participating laboratories should submit
appropriate documentation demonstrating
compliance with the above criteria to the responsible physician. To demonstrate compliance with the first of the above criteria, participating laboratories should submit the
following documentation for each analyte
they plan to analyze (note that each document should cover a period of at least 8 consecutive quarters, and that the period designated by the term ‘‘regular analyses’’ is at
least once a quarter):
1. Copies of laboratory reports providing
results from regular analyses of the appropriate analyte (CDB, CDU and/or B2MU);
2. Copies of 1 or more signed and executed
contracts for the provision of regular anal-
§ 1910.1027
yses of the appropriate analyte (CDB, CDU
and/or B2MU); or,
3. Copies of invoices sent to 1 or more clients requesting payment for the provision of
regular analyses of the appropriate analyte
(CDB, CDU and/or B2MU). Whatever the form
of documentation submitted, the specific
analytic procedures conducted should be
identified directly. The forms that are copied
for submission to the responsible physician
also should identify the laboratory which
provided these analyses.
To demonstrate compliance with the second of the above criteria, a laboratory
should submit to the responsible physician
an internal QA/QC plan detailing the standard operating procedures to be adopted for
satisfying the recommended QA/QC procedures for the analysis of each specific
analyte (CDB, CDU and/or B2MU). Procedures for internal QA/QC programs are detailed in Section 3.3.1 below.
To satisfy the third of the above criteria,
laboratories analyzing for CDU or B2MU also
should submit a QA/QC plan for creatinine
analysis (CRTU); the QA/QC plan and characterization analyses for CRTU must come
from the laboratory performing the CRTU
analysis, even if the CRTU analysis is being
performed by a contract laboratory.
Laboratories enrolling in the CTQ program
(to satisfy the last of the above criteria)
must remit, with the enrollment application,
an initial fee of approximately $100 per
analyte. (Note that this fee is only an estimate, and is subject to revision without notice.) Laboratories should indicate on the application that they agree to have proficiency
test results sent by the CTQ directly to the
physicians designated by participating laboratories.
Once a laboratory’s application is processed by the CTQ, the laboratory will be assigned a code number which will be provided
to the laboratory on the initial confirmation
form, along with identification of the specific analytes for which the laboratory is
participating. Confirmation of participation
will be sent by the CTQ to physicians designated by the applicant laboratory.
3.2.2
Recommended Review of Laboratories
Selected to Perform Analyses
Six months after being selected initially to
perform analyte determinations, the status
of participating laboratories should be reviewed by the responsible physicians. Such
reviews should then be repeated every 6
months or whenever additional proficiency
or QA/QC documentation is received (whichever occurs first).
As soon as the responsible physician has
received the CTQ results from the first 3
rounds of proficiency testing (i.e., 3 sets of 3
samples each for CDB, CDU and/or B2MU) for
a participating laboratory, the status of the
laboratory’s continued participation should
181
§ 1910.1027
be reviewed. Over the same initial 6-month
period, participating laboratories also should
provide responsible physicians the results of
their internal QA/QC monitoring program
used to assess performance for each analyte
(CDB, CDU and/or B2MU) for which the laboratory performs determinations. This information should be submitted using appropriate forms and documentation.
The status of each participating laboratory
should be determined for each analyte (i.e.,
whether the laboratory satisfies minimum
proficiency guidelines based on the proficiency samples sent by the CTQ and the results of the laboratory’s internal QA/QC program). To maintain competency for analysis
of CDB, CDU and/or B2MU during the first
review, the laboratory should satisfy performance requirements for at least 2 of the 3
proficiency samples provided in each of the 3
rounds completed over the 6-month period.
Proficiency should be maintained for the
analyte(s) for which the laboratory conducts
determinations.
To continue participation for CDU and/or
B2MU analyse, laboratories also should either maintain accreditation for CRTU analysis in the CAP program and participate in
the CAP surveys, or they should contract the
CDU and B2MU analyses to a laboratory
which satisfies these requirements (or which
can provide documentation of accreditation/
participation in an equivalent program).
The performance requirement for CDB
analysis is defined as an analytical result
within ±1 µg/l blood or 15% of the consensus
mean (whichever is greater). For samples exhibiting a consensus mean less than 1 µg/l,
the performance requirement is defined as a
concentration between the detection limit of
the analysis and a maximum of 2 µg/l. The
purpose for redefining the acceptable interval for low CDB values is to encourage proper reporting of the actual values obtained
during measurement; laboratories, therefore,
will not be penalized (in terms of a narrow
range of acceptability) for reporting measured concentrations smaller than 1 µg/l.
The performance requirement for CDU
within ±1 µg/l urine or 15% of the consensus
mean (whichever is greater). For samples exhibiting a consensus mean less than 1 µg/l
urine, the performance requirement is defined as a concentration between the detection limit of the analysis and a maximum of
2 µg/l urine. Laboratories also should demonstrate proficiency in creatinine analysis
as defined by the CAP. Note that reporting
CDU results, other than for the CTQ proficiency samples (i.e., compliance samples),
should be accompanied with results of analyses for CRTU, and these 2 sets of results
should be combined to provide a measure of
CDU in units of µg/g CRTU.
The performance requirement for B2MU is
defined as analytical results within ± 15% of
the consensus mean. Note that reporting
B2MU results, other than for CTQ proficiency samples (i.e., compliance samples),
should be accompanied with results of analyses for CRTU, and these 2 sets of results
should be combined to provide a measure of
B2MU in units of µg/g CRTU.
There are no recommended performance
checks for CRTU analyses. As stated previously, laboratories performing CRTU analysis in support of CDU or B2MU analyses
should be accredited by the CAP, and participating in the CAP’s survey for CRTU.
Following the first review, the status of
each participating laboratory should be reevaluated at regular intervals (i.e., corresponding to receipt of results from each
succeeding round of proficiency testing and
submission of reports from a participating
laboratory’s internal QA/QC program).
After a year of collecting proficiency test
results, the following proficiency criterion
should be added to the set of criteria used to
determine the participating laboratory’s status (for analyzing CDB, CDU and/or B2MU):
A participating laboratory should not fail
performance requirements for more than 4
samples from the 6 most recent consecutive
rounds used to assess proficiency for CDB,
CDU and/or B2MU separately (i.e., a total of
18 discrete proficiency samples for each
analyte). Note that this requirement does
not replace, but supplements, the recommendation that a laboratory should satisfy the performance criteria for at least 2 of
the 3 samples tested for each round of the
program.
3.2.3 Recommendations
for
Selecting
Among Newly-Formed Laboratories (or
Laboratories that Previously Failed to
Meet the Protocol Guidelines)
OSHA recommends that laboratories that
have not previously provided commercial
analyses of CDB, CDU and/or B2MU (or have
done so for a period less than 2 years), or
which have provided these analyses for 2 or
more years but have not conformed previously with these protocol guidelines,
should satisfy the following provisions for
each analyte for which determinations are to
be made prior to being selected to analyze
biological samples under the medical monitoring program:
1. Submit to the responsible physician an
internal QA/QC plan detailing the standard
operating procedures to be adopted for satisfying the QA/QC guidelines (guidelines for internal QA/QC programs are detailed in Section 3.3.1);
2. Submit to the responsible physician the
results of the initial characterization analyses for each analyte for which determinations are to be made;
3. Submit to the responsible physician the
results, for the initial 6-month period, of the
internal QA/QC program for each analyte for
182
which determinations are to be made (if no
commercial analyses have been conducted
previously, a minimum of 2 mock standardization trials for each analyte should be
completed per month for a 6-month period);
4. Enroll in the CTQ program for the appropriate analyte for which determinations are
to be made, and arrange to have the CTQ
program submit the initial confirmation of
participation and proficiency test results directly to the designated physicians. Note
that the designated physician should receive
results from 3 completed rounds from the
CTQ program before approving a laboratory
for participation in the biological monitoring program;
5. Laboratories seeking participation for
CDU and/or B2MU analyses should submit to
the responsible physician documentation of
accreditation by the CAP for CRTU analyses
performed in conjunction with CDU and/or
B2MU determinations (if CRTU analyses are
conducted by a contract laboratory, this laboratory should submit proof of CAP accreditation to the responsible physician); and,
6. Documentation should be submitted on
an appropriate form.
To participate in CDB, CDU and/or B2MU
analyses, the laboratory should satisfy the
above criteria for a minimum of 2 of the 3
proficiency samples provided in each of the 3
rounds of the CTQ program over a 6-month
period; this procedure should be completed
for each appropriate analyte. Proficiency
should be maintained for each analyte to
continue participation. Note that laboratories seeking participation for CDU or
B2MU also should address the performance
requirements for CRTU, which involves providing evidence of accreditation by the CAP
and participation in the CAP surveys (or an
equivalent program).
The performance requirement for CDB
within ±1 µg/l or 15% of the consensus mean
(whichever is greater). For samples exhibiting a consensus mean less than 1 µg/l, the
performance requirement is defined as a concentration between the detection limit of
the analysis and a maximum of 2 µg/l. The
purpose of redefining the acceptable interval
for low CDB values is to encourage proper reporting of the actual values obtained during
measurement; laboratories, therefore, will
not be penalized (in terms of a narrow range
of acceptability) for reporting measured concentrations less than 1 µg/l.
The performance requirement for CDU
within ±1 µg/l urine or 15% of the consensus
mean (whichever is greater). For samples exhibiting a consensus mean less than 1 µg/l
urine, the performance requirement is defined as a concentration that falls between
the detection limit of the analysis and a
maximum of 2 µg/l urine. Performance requirements for the companion CRTU anal-
§ 1910.1027
ysis (defined by the CAP) also should be met.
Note that reporting CDU results, other than
for CTQ proficiency testing should be accompanied with results of CRTU analyses, and
these 2 sets of results should be combined to
provide a measure of CDU in units of µg/g
CRTU.
The performance requirement for B2MU is
defined as an analytical result within ±15%
of the consensus mean. Note that reporting
B2MU results, other than for CTQ proficiency testing should be accompanied with
results of CRTU analysis, these 2 sets of results should be combined to provide a measure of B2MU in units of µg/g CRTU.
Once a new laboratory has been approved
by the responsible physician for conducting
analyte determinations, the status of this
approval should be reviewed periodically by
the responsible physician as per the criteria
presented under Section 3.2.2.
Laboratories which have failed previously
to gain approval of the responsible physician
for conducting determinations of 1 or more
analytes due to lack of compliance with the
criteria defined above for existing laboratories (Section 3.2.1), may obtain approval by
satisfying the criteria for newly-formed laboratories defined under this section; for
these laboratories, the second of the above
criteria may be satisfied by submitting a
new set of characterization analyses for each
analyte for which determinations are to be
made.
Reevaluation of these laboratories is discretionary on the part of the responsible
physician. Reevaluation, which normally
takes about 6 months, may be expedited if
the laboratory can achieve 100% compliance
with the proficiency test criteria using the 6
samples of each analyte submitted to the
CTQ program during the first 2 rounds of
proficiency testing.
For laboratories seeking reevaluation for
CDU or B2MU analysis, the guidelines for
CRTU analyses also should be satisfied, including accreditation for CRTU analysis by
the CAP, and participation in the CAP survey program (or accreditation/participation
in an equivalent program).
3.2.4 Future Modifications to the Protocol
Guidelines
As participating laboratories gain experience with analyses for CDB, CDU and B2MU,
it is anticipated that the performance
achievable by the majority of laboratories
should improve until it approaches that reported by the research groups which developed each method. OSHA, therefore, may
choose to recommend stricter performance
guidelines in the future as the overall performance of participating laboratories improves.
183
§ 1910.1027
3.3
Guidelines for Record Keeping and
Reporting
To comply with these guidelines, participating laboratories should satisfy the abovestated performance and proficiency recommendations, as well as the following internal QA/QC, record keeping, and reporting
provisions.
If a participating laboratory fails to meet
the provisions of these guidelines, it is recommended that the responsible physician
disapprove further analyses of biological
samples by that laboratory until it demonstrates compliance with these guidelines.
On disapproval, biological samples should be
sent to a laboratory that can demonstrate
compliance with these guidelines, at least
until the former laboratory is reevaluated by
the responsible physician and found to be in
compliance.
The following record keeping and reporting
procedures should be practiced by participating laboratories.
3.3.1
Internal Quality Assurance/Quality
Control Procedures
Laboratories participating in the cadmium
monitoring program should develop and
maintain an internal quality assurance/quality control (QA/QC) program that incorporates procedures for establishing and
maintaining control for each of the analytic
procedures (determinations of CDB, CDU
and/or B2MU) for which the laboratory is
seeking participation. For laboratories analyzing CDU and/or B2MU, a QA/QC program
for CRTU also should be established.
Written documentation of QA/QC procedures should be described in a formal QA/QC
plan; this plan should contain the following
information: Sample acceptance and handling procedures (i.e., chain-of-custody);
sample preparation procedures; instrument
parameters; calibration procedures; and, calculations. Documentation of QA/QC procedures should be sufficient to identify analytical problems, define criteria under which
analysis of compliance samples will be suspended, and describe procedures for corrective actions.
3.3.1.1 QA/QC procedures for establishing
control of CDB and CDU analyses
The QA/QC program for CDB and CDU
should address, at a minimum, procedures
involved in calibration, establishment of
control limits, internal QC analyses and
maintaining control, and corrective-action
protocols. Participating laboratory should
develop and maintain procedures to assure
that analyses of compliance samples are
within control limits, and that these procedures are documented thoroughly in a QA/QC
plan.
A nonmandatory QA/QC protocol is presented in Attachment 1. This attachment is
illustrative of the procedures that should be
addressed in a proper QA/QC program.
Calibration. Before any analytic runs are
conducted, the analytic instrument should
be calibrated. Calibration should be performed at the beginning of each day on
which QC and/or compliance samples are run.
Once calibration is established, QC or compliance samples may be run. Regardless of
the type of samples run, about every fifth
sample should serve as a standard to assure
that calibration is being maintained.
Calibration is being maintained if the
standard is within ±15% of its theoretical
value. If a standard is more than ±15% of its
theoretical value, the run has exceeded control limits due to calibration error; the entire set of samples then should be reanalyzed
after recalibrating or the results should be
recalculated based on a statistical curve derived from that set of standards.
It is essential that the value of the highest
standard analyzed be higher than the highest
sample analyzed; it may be necessary, therefore, to run a high standard at the end of the
run, which has been selected based on results
obtained over the course of the run (i.e.,
higher than any standard analyzed to that
point).
Standards should be kept fresh; as samples
age, they should be compared with new
standards and replaced if necessary.
Internal Quality Control Analyses. Internal
QC samples should be determined interspersed with analyses of compliance samples.
At a minimum, these samples should be run
at a rate of 5% of the compliance samples or
at least one set of QC samples per analysis of
compliance samples, whichever is greater. If
only 2 samples are run, they should contain
different levels of cadmium.
Internal QC samples may be obtained as
commercially-available reference materials
and/or they may be internally prepared. Internally-prepared samples should be well
characterized and traced, or compared to a
reference material for which a consensus
value is available.
Levels of cadmium contained in QC samples should not be known to the analyst
prior to reporting the results of the analysis.
Internal QC results should be plotted or
charted in a manner which describes sample
recovery and laboratory control limits.
Internal Control Limits. The laboratory protocol for evaluating internal QC analyses per
control limits should be clearly defined.
Limits may
℘ be based on statistical methods
(e.g., as 2σ from the laboratory mean recovery), or on proficiency testing limits
(e.g.,±1µg or 15% of the mean, whichever is
greater). Statistical limits that exceed ±40%
should be reevaluated to determine the
source error in the analysis.
When laboratory limits are exceeded, analytic work should terminate until the source
184
of error is determined and corrected; compliance samples affected by the error should be
reanalyzed. In addition, the laboratory protocol should address any unusual trends that
develop which may be biasing the results.
Numerous, consecutive results above or
below laboratory mean recoveries, or outside
laboratory statistical limits, indicate that
problems may have developed.
Corrective Actions. The QA/QC plan should
document in detail specific actions taken if
control limits are exceeded or unusual trends
develop. Corrective actions should be noted
on an appropriate form, accompanied by supporting documentation.
In addition to these actions, laboratories
should include whatever additional actions
are necessary to assure that accurate data
are reported to the responsible physicians.
Reference Materials. The following reference
materials may be available:
Cadmium in Blood (CDB)
1. Centre de Toxicologie du Quebec, Le
Centre Hospitalier de l’Universite Laval, 2705
boul. Laurier, Quebec, Que., Canada G1V 4G2.
(Prepared 6 times per year at 1–15 µg Cd/l.)
2. H. Marchandise, Community Bureau of
Reference-BCR, Directorate General XII,
Commission of the European Communities,
200, rue de la Loi, B–1049, Brussels, Belgium.
(Prepared as Bl CBM–1 at 5.37 µg Cd/l, and Bl
CBM–2 at 12.38 µg Cd/l.)
3. Kaulson Laboratories Inc., 691 Bloomfield Ave., Caldwell, NJ 07006; tel: (201) 226–
9494, FAX (201) 226–3244. (Prepared as #0141
[As, Cd, Hg, Pb] at 2 levels.)
Cadmium in Urine (CDU)
1. Centre de Toxicologie du Quebec, Le
Centre Hospitalier de l’Universite Laval, 2705
boul. Laurier, Quebec, Que., Canada G1V 4G2.
(Prepared 6 times per year.)
2. National Institute of Standards and
Technology (NIST), Dept. of Commerce, Gaithersburg, MD; tel: (301) 975–6776. (Prepared
as SRM 2670 freeze-dried urine [metals]; set
includes normal and elevated levels of metals; cadmium is certified for elevated level of
88.0 µg/l in reconstituted urine.)
3. Kaulson Laboratories Inc., 691 Bloomfield Ave., Caldwell, NJ 07006; tel: (201) 226–
9494, FAX (201) 226–3244. (Prepared as #0140
[As, Cd, Hg, Pb] at 2 levels.)
3.3.1.2 QA/QC procedures for establishing
control of B2MU
§ 1910.1027
Examples of performance summaries that
can be provided include measurements of accuracy (i.e., the means of measured values
versus target values for the control samples)
and precision (i.e., based on duplicate analyses). It is recommended that the accuracy
and precision measurements be compared to
those reported as achievable by the
Pharmacia Delphia kit (Pharmacia 1990) to
determine if and when unsatisfactory analyses have arisen. If the measurement error of
1 or more of the control samples is more
than 15%, the run exceeds control limits.
Similarly, this decision is warranted when
the average CV for duplicate samples is
greater than 5%.
3.3.2 Procedures for Record Keeping
To satisfy reporting requirements for commercial analyses of CDB, CDU and/or B2MU
performed for the medical monitoring program mandated under the cadmium rule,
participating laboratories should maintain
the following documentation for each
analyte:
1. For each analytic instrument on which
analyte determinations are made, records relating to the most recent calibration and QC
sample analyses;
2. For these instruments, a tabulated
record for each analyte of those determinations found to be within and outside of control limits over the past 2 years;
3. Results for the previous 2 years of the
QC sample analyses conducted under the internal QA/QC program (this information
should be: Provided for each analyte for
which determinations are made and for each
analytic instrument used for this purpose,
sufficient to demonstrate that internal QA/
QC programs are being executed properly,
and consistent with data sent to responsible
physicians.
4. Duplicate copies of monitoring results
for each analyte sent to clients during the
previous 5 years, as well as associated information; supporting material such as chainof-custody forms also should be retained;
and,
5. Proficiency test results and related materials received while participating in the
CTQ interlaboratory program over the past 2
years; results also should be tabulated to
provide a serial record of relative error (derived per Section 3.3.3 below).
3.3.3 Reporting Procedures
A written, detailed QA/QC plan for B2MU
analysis should be developed. The QA/QC
plan should contain a protocol similar to
those protocols developed for the CDB/CDU
analyses. Differences in analyses may warrant some differences in the QA/QC protocol,
but procedures to ensure analytical integrity
should be developed and followed.
Participating laboratories should maintain
these documents: QA/QC program plans; QA/
QC status reports; CTQ proficiency program
reports; and, analytical data reports. The information that should be included in these
reports is summarized in Table 2; a copy of
each report should be sent to the responsible
physician.
185
§ 1910.1027
TABLE 2—REPORTING PROCEDURES FOR LABORATORIES PARTICIPATING IN THE CADMIUM MEDICAL
MONITORING PROGRAM
Report
Frequency (time frame)
Contents
1 QA/QC Program Plan ...........
Once (initially) .........................
A detailed description of the QA/QC protocol to be established by the laboratory to maintain control of analyte determinations.
Results of the QC samples incorporated into regular runs for
each instrument (over the period since the last report).
Results from the last full year of proficiency samples submitted to the CTQ program and Results of the 100 most recent QC samples incorporated into regular runs for each
instrument.
Date the sample was received; Date the sample was analyzed; Appropriate chain-of-custody information; Types of
analyses performed; Results of the requested analyses and
Copy of the most current proficiency report.
2 QA/QC Status Report ...........
Every 2 months .......................
3 Proficiency Report .................
Attached to every data report
4 Analytical Data Report ..........
For all reports of data results ..
As noted in Section 3.3.1, a QA/QC program
plan should be developed that documents internal QA/QC procedures (defined under Section 3.3.1) to be implemented by the participating laboratory for each analyte; this plan
should provide a list identifying each instrument used in making analyte determinations.
A QA/QC status report should be written
bimonthly for each analyte. In this report,
the results of the QC program during the reporting period should be reported for each
analyte in the following manner: The number (N) of QC samples analyzed during the
period; a table of the target levels defined for
each sample and the corresponding measured
values; the mean of F/T value (as defined
below) for the set of QC samples run during
the period; and, use of X̄ ±2s√ (as defined
below) for the set of QC samples run during
the period as a measure of precision.
As noted in Section 2, an F/T value for a
QC sample is the ratio of the measured concentration of analyte to the established (i.e.,
reference) concentration of analyte for that
QC sample. The equation below describes the
derivation of the mean for F/T values, X,
(with N being the total number of samples
analyzed):
pools then should be derived. Several precision estimates should be provided for concentrations which differ in average value.
These precision measures may be used to
document improvements in performance
with regard to the combined pool.
Participating laboratories should use the
CTQ proficiency program for each analyte.
Results of the this program will be sent by
CTQ directly to physicians designated by the
participating laboratories. Proficiency results from the CTQ program are used to establish the accuracy of results from each
participating laboratory, and should be provided to responsible physicians for use in
trend analysis. A proficiency report consisting of these proficiency results should accompany data reports as an attachment.
For each analyte, the proficiency report
should include the results from the 6 previous proficiency rounds in the following format:
1. Number (N) of samples analyzed;
2. Mean of the target levels, (1/N)Σi, with Ti
being a consensus mean for the sample;
3. Mean of the measurements, (1/N)Σi, with
Mi being a sample measurement;
4. A measure of error defined by:
∑ (F / T)
X=
(1/N)Σ(Ti¥ Mi)2
Analytical data reports should be submitted to responsible physicians directly.
For each sample, report the following information: The date the sample was received;
the date the sample was analyzed; appropriate chain-of-custody information; the
type(s) of analyses performed; and, the results of the analyses. This information
should be reported on a form similar to the
form provided an appropriate form. The most
recent proficiency program report should accompany the analytical data reports (as an
attachment).
Confidence intervals for the analytical results should be reported as X±2s√, with X
being the measured value and 2s√ the standard deviation calculated as described above.
N
The standard deviation, s√, for these measurements is derived using the following equation (note that 2s√ is twice this value):
(

∧
∑ F/T−X
σ=

N −1

)
1
2
2



The nonmandatory QA/QC protocol (see Attachment 1) indicates that QC samples
should be divided into several discrete pools,
and a separate estimate of precision for each
186
For CDU or B2MU results, which are combined with CRTU measurements for proper
reporting, the 95% confidence limits are derived from the limits for CDU or B2MU, (p),
and the limits for CRTU, (q), as follows:
(
 1  2
2
2
2
± 2  Y ×p +X ×q
Y Y 
X
)
1
2
For these calculations, X± p is the measurement and confidence limits for CDU or
B2MU, and Y± q is the measurement and confidence limit for CRTU.
Participating laboratories should notify
responsible physicians as soon as they receive information indicating a change in
their accreditation status with the CTQ or
the CAP. These physicians should not be expected to wait until formal notice of a status
change has been received from the CTQ or
the CAP.
3.4
Instructions to Physicians
Physicians responsible for the medical
monitoring of cadmium-exposed workers
must collect the biological samples from
workers; they then should select laboratories
to perform the required analyses, and should
interpret the analytic results.
3.4.1
Sample Collection and Holding
Procedures
Blood Samples. The following procedures
are recommended for the collection, shipment and storage of blood samples for CDB
analysis to reduce analytical variablility;
these recommendations were obtained primarily through personal communications
with J.P. Weber of the CTQ (1991), and from
reports by the Centers for Disease Control
(CDC, 1986) and Stoeppler and Brandt (1980).
To the extent possible, blood samples
should be collected from workers at the same
time of day. Workers should shower or thoroughly wash their hands and arms before
blood samples are drawn. The following materials are needed for blood sample collection: Alcohol wipes; sterile gauze sponges;
band-aids; 20-gauge, 1.5-in. stainless steel
needles (sterile); preprinted labels; tourniquets; vacutainer holders; 3-ml ‘‘metal
free’’ vacutainer tubes (i.e., dark-blue caps),
with EDTA as an anti-coagulant; and,
styrofoam vacutainer shipping containers.
Whole blood samples are taken by
venipuncture. Each blue-capped tube should
be labeled or coded for the worker and company before the sample is drawn. (Bluecapped tubes are recommended instead of
red-capped tubes because the latter may consist of red coloring pigment containing cadmium, which could contaminate the samples.) Immediately after sampling, the
vacutainer tubes must be thoroughly mixed
by inverting the tubes at least 10 times
§ 1910.1027
manually or mechanically using a Vortex device (for 15 sec). Samples should be refrigerated immediately or stored on ice until
they can be packed for shipment to the participating laboratory for analysis.
The CDC recommends that blood samples
be shipped with a ‘‘cool pak’’ to keep the
samples cold during shipment. However, the
CTQ routinely ships and receives blood samples for cadmium analysis that have not
been kept cool during shipment. The CTQ
has found no deterioration of cadmium in biological fluids that were shipped via parcel
post without a cooling agent, even though
these deliveries often take 2 weeks to reach
their destination.
Urine Samples. The following are recommended procedures for the collection,
shipment and storage of urine for CDU and
B2MU analyses, and were obtained primarily
through personal communications with J.P.
Weber of the CTQ (1991), and from reports by
the CDC (1986) and Stoeppler and Brandt
(1980).
Single ‘‘spot’’ samples are recommended.
As B2M can degrade in the bladder, workers
should first empty their bladder and then
drink a large glass of water at the start of
the visit. Urine samples then should be collected within 1 hour. Separate samples
should be collected for CDU and B2MU using
the following materials: Sterile urine collection cups (250 ml); small sealable plastic
bags; preprinted labels; 15-ml polypropylene
or polyethylene screw-cap tubes; lab gloves
(‘‘metal free’’); and, preservatives (as indicated).
The sealed collection cup should be kept in
the plastic bag until collection time. The
workers should wash their hands with soap
and water before receiving the collection
cup. The collection cup should not be opened
until just before voiding and the cup should
be sealed immediately after filling. It is important that the inside of the container and
cap are not touched by, or come into contact
with, the body, clothing or other surfaces.
For CDU analyzes, the cup is swirled gently to resuspend any solids, and the 15-ml
tube is filled with 10-12 ml urine. The CDC
recommends the addition of 100 µ l concentrated HNO3 as a preservative before sealing the tube and then freezing the sample.
The CTQ recommends minimal handling and
does not acidify their interlaboratory urine
reference materials prior to shipment, nor do
they freeze the sample for shipment. At the
CTQ, if the urine sample has much sediment,
the sample is acidified in the lab to free any
cadmium in the precipitate.
For B2M, the urine sample should be collected directly into a polyethylene bottle
previously washed with dilute nitric acid.
The pH of the urine should be measured and
adjusted to 8.0 with 0.1 N NaOH immediately
187
§ 1910.1027
following collection. Samples should be frozen and stored at –20 °C until testing is performed. The B2M in the samples should be
stable for 2 days when stored at 2–8 °C, and
for at least 2 months at –20 °C. Repeated
freezing and thawing should be avoided to
prevent denaturing the B2M (Pharmacia
1990).
3.4.2
Recommendations for Evaluating
Laboratories
Using standard error data and the results
of proficiency testing obtained from CTQ, responsible physicians can make an informed
choice of which laboratory to select to analyze biological samples. In general, laboratories with small standard errors and little
disparity between target and measured values tend to make precise and accurate sample determinations. Estimates of precision
provided to the physicians with each set of
monitoring results can be compared to previously-reported proficiency and precision
estimates. The latest precision estimates
should be at least as small as the standard
error reported previously by the laboratory.
Moreover, there should be no indication that
precision is deteriorating (i.e., increasing
values for the precision estimates). If precision is deteriorating, physicians may decide
to use another laboratory for these analyses.
QA/QC information provided by the participating laboratories to physicians can, therefore, assist physicians in evaluating laboratory performance.
3.4.3
Use and Interpretation of Results
When the responsible physician has received the CDB, CDU and/or B2MU results,
these results must be compared to the action
levels discussed in the final rule for cadmium. The comparison of the sample results
to action levels is straightforward. The
measured value reported from the laboratory
can be compared directly to the action levels; if the reported value exceeds an action
level, the required actions must be initiated.
4.0
Background
Cadmium is a naturally-occurring environmental contaminant to which humans are
continually exposed in food, water, and air.
The average daily intake of cadmium by the
U.S. population is estimated to be 10–20 µg/
day. Most of this intake is via ingestion, for
which absorption is estimated at 4–7%
(Kowal et al. 1979). An additional nonoccupational source of cadmium is smoking tobacco; smoking a pack of cigarettes a day
adds an additional 2–4 µg cadmium to the
daily intake, assuming absorption via inhalation of 25–35% (Nordberg and Nordberg 1988;
Friberg and Elinder 1988; Travis and Haddock
1980).
Exposure to cadmium fumes and dusts in
an occupational setting where air concentra-
tions are 20–50 µg/m3 results in an additional
daily intake of several hundred micrograms
(Friberg and Elinder 1988, p. 563). In such a
setting, occupational exposure to cadmium
occurs primarily via inhalation, although additional exposure may occur through the ingestion of material via contaminated hands
if workers eat or smoke without first washing. Some of the particles that are inhaled
initially may be ingested when the material
is deposited in the upper respiratory tract,
where it may be cleared by mucociliary
transport and subsequently swallowed.
Cadmium introduced into the body
through inhalation or ingestion is transported by the albumin fraction of the blood
plasma to the liver, where it accumulates
and is stored principally as a bound form
complexed with the protein metallothionein.
Metallothionein-bound cadmium is the main
form of cadmium subsequently transported
to the kidney; it is these 2 organs, the liver
and kidney, in which the majority of the
cadmium body burden accumulates. As much
as one half of the total body burden of cadmium may be found in the kidneys (Nordberg
and Nordberg 1988).
Once cadmium has entered the body, elimination is slow; about 0.02% of the body burden is excreted per day via urinary/fecal
elimination. The whole-body half-life of cadmium is 10–35 years, decreasing slightly with
increasing age (Travis and Haddock 1980).
The continual accumulation of cadmium is
the basis for its chronic noncarcinogenic toxicity. This accumulation makes the kidney
the target organ in which cadmium toxicity
usually is first observed (Piscator 1964).
Renal damage may occur when cadmium levels in the kidney cortex approach 200 µg/g
wet tissue-weight (Travis and Haddock 1980).
The kinetics and internal distribution of
cadmium in the body are complex, and depend on whether occupational exposure to
cadmium is ongoing or has terminated. In
general, cadmium in blood is related principally to recent cadmium exposure, while
cadmium in urine reflects cumulative exposure (i.e., total body burden) (Lauwerys et al.
1976; Friberg and Elinder 1988).
4.1
Health Effects
Studies of workers in a variety of industries indicate that chronic exposure to cadmium may be linked to several adverse
health effects including kidney dysfunction,
reduced pulmonary function, chronic lung
disease and cancer (Federal Register 1990).
The primary sites for cadmium-associated
cancer appear to be the lung and the prostate.
Cancer. Evidence for an association between cancer and cadmium exposure comes
from both epidemiological studies and animal experiments. Pott (1965) found a statistically significant elevation in the incidence
188
of prostate cancer among a cohort of cadmium workers. Other epidemiology studies
also report an elevated incidence of prostate
cancer; however, the increases observed in
these other studies were not statistically
significant (Meridian Research, Inc. 1989).
One study (Thun et al. 1985) contains sufficiently quantitative estimates of cadmium
exposure to allow evaluation of dose-response relationships between cadmium exposure and lung cancer. A statistically significant excess of lung cancer attributed to cadmium exposure was found in this study, even
after accounting for confounding variables
such as coexposure to arsenic and smoking
habits (Meridian Research, Inc. 1989).
Evidence for quantifying a link between
lung cancer and cadmium exposure comes
from a single study (Takenaka et al. 1983). In
this study, dose-response relationships developed from animal data were extrapolated to
humans using a variety of models. OSHA
chose the multistage risk model for estimating the risk of cancer for humans using
these animal data. Animal injection studies
also suggest an association between cadmium exposure and cancer, particularly observations of an increased incidence of tumors at sites remote from the point of injection. The International Agency for Research
on Cancer (IARC) (Supplement 7, 1987) indicates that this, and related, evidence is sufficient to classify cadmium as an animal carcinogen. However, the results of these injection studies cannot be used to quantify risks
attendant to human occupational exposures
due to differences in routes of exposure (Meridian Research, Inc. 1989).
Based on the above-cited studies, the U.S.
Environmental Protection Agency (EPA)
classifies cadmium as ‘‘B1,’’ a probable
human carcinogen (USEPA 1985). IARC in
1987 recommended that cadmium be listed as
a probable human carcinogen.
Kidney Dysfunction. The most prevalent
nonmalignant effect observed among workers chronically exposed to cadmium is kidney dysfunction. Initially, such dysfunction
is manifested by proteinuria (Meridian Research, Inc. 1989; Roth Associates, Inc. 1989).
Proteinuria associated with cadmium exposure is most commonly characterized by excretion of low-molecular weight proteins
(15,000–40,000 MW), accompanied by loss of
electrolytes, uric acid, calcium, amino acids,
and phosphate. Proteins commonly excreted
include β-2-microglobulin (B2M), retinolbinding protein (RBP), immunoglobulin light
chains, and lysozyme. Excretion of low molecular weight proteins is characteristic of
damage to the proximal tubules of the kidney (Iwao et al. 1980).
Exposure to cadmium also may lead to urinary excretion of high-molecular weight proteins such as albumin, immunoglobulin G,
and glycoproteins (Meridian Research, Inc.
1989; Roth Associates, Inc. 1989). Excretion of
§ 1910.1027
high-molecular weight proteins is indicative
of damage to the glomeruli of the kidney.
Bernard et al. (1979) suggest that cadmiumassociated damage to the glomeruli and
damage to the proximal tubules of the kidney develop independently of each other, but
may occur in the same individual.
Several studies indicate that the onset of
low-molecular weight proteinuria is a sign of
irreversible kidney damage (Friberg et al.
1974; Roels et al. 1982; Piscator 1984; Elinder
et al. 1985; Smith et al. 1986). For many
workers, once sufficiently elevated levels of
B2M are observed in association with cadmium exposure, such levels do not appear to
return to normal even when cadmium exposure is eliminated by removal of the worker
from the cadmium-contaminated work environment (Friberg, exhibit 29, 1990).
Some studies indicate that cadmium-induced proteinuria may be progressive; levels
of B2MU increase even after cadmium exposure has ceased (Elinder et al. 1985). Other researchers have reached similar conclusions
(Frieburg testimony, OSHA docket exhibit
29, Elinder testimony, OSHA docket exhibit
55, and OSHA docket exhibits 8–86B). Such
observations are not universal, however
(Smith et al. 1986; Tsuchiya 1976). Studies in
which proteinuria has not been observed,
however, may have initiated the reassessment too early (Meridian Research, Inc.1989;
Roth Associates, Inc. 1989; Roels 1989).
A quantitative assessment of the risks of
developing kidney dysfunction as a result of
cadmium exposure was performed using the
data from Ellis et al. (1984) and Falck et al.
(1983). Meridian Research, Inc. (1989) and
Roth Associates, Inc. (1989) employed several
mathematical models to evaluate the data
from the 2 studies, and the results indicate
that cumulative cadmium exposure levels
between 5 and 100 µg-years/m3 correspond
with a one-in-a-thousand probability of developing kidney dysfunction.
When cadmium exposure continues past
the onset of early kidney damage (manifested
as
proteinuria),
chronic
nephrotoxicity may occur (Meridian Research, Inc. 1989; Roth Associates, Inc. 1989).
Uremia, which is the loss of the glomerulus’
ability to adequately filter blood, may result. This condition leads to severe disturbance of electrolyte concentrations, which
may result in various clinical complications
including atherosclerosis, hypertension, pericarditis, anemia, hemorrhagic tendencies,
deficient cellular immunity, bone changes,
and other problems. Progression of the disease may require dialysis or a kidney transplant.
Studies in which animals are chronically
exposed to cadmium confirm the renal effects observed in humans (Friberg et al.
1986). Animal studies also confirm cadmiumrelated problems with calcium metabolism
and associated skeletal effects, which also
189
§ 1910.1027
have been observed among humans. Other effects commonly reported in chronic animal
studies include anemia, changes in liver
morphology, immunosuppression and hypertension. Some of these effects may be associated with cofactors; hypertension, for example, appears to be associated with diet, as
well as with cadmium exposure. Animals injected with cadmium also have shown testicular necrosis.
4.2
Objectives for Medical Monitoring
In keeping with the observation that renal
disease tends to be the earliest clinical manifestation of cadmium toxicity, the final cadmium standard mandates that eligible workers must be medically monitored to prevent
this condition (as well as cadmimum-induced
cancer). The objectives of medical-monitoring, therefore, are to: Identify workers at
significant risk of adverse health effects
from excess, chronic exposure to cadmium;
prevent future cases of cadmium-induced disease; detect and minimize existing cadmiuminduced disease; and, identify workers most
in need of medical intervention.
The overall goal of the medical monitoring
program is to protect workers who may be
exposed continuously to cadmium over a 45year occupational lifespan. Consistent with
this goal, the medical monitoring program
should assure that:
1. Current exposure levels remain sufficiently low to prevent the accumulation of
cadmium body burdens sufficient to cause
disease in the future by monitoring CDB as
an indicator of recent cadmium exposure;
2. Cumulative body burdens, especially
among workers with undefined historical exposures, remain below levels potentially capable of leading to damage and disease by assessing CDU as an indicator of cumulative
exposure to cadmium; and,
3. Health effects are not occurring among
exposed workers by determining B2MU as an
early indicator of the onset of cadmium-induced kidney disease.
4.3
Indicators of Cadmium Exposure and
Disease
Cadmium is present in whole blood bound
to albumin, in erythrocytes, and as a
metallothionein-cadmium
complex.
The
metallothionein-cadmium complex that represents the primary transport mechanism for
cadmium delivery to the kidney. CDB concentrations in the general, nonexposed population average 1 µg Cd/l whole blood, with
smokers exhibiting higher levels (see Section
5.1.6). Data presented in Section 5.1.6 shows
that 95% of the general population not occupationally exposed to cadmium have CDB
levels less than 5 µg Cd/l.
If total body burdens of cadmium remain
low, CDB concentrations indicate recent exposure (i.e., daily intake). This conclusion is
based on data showing that cigarette smokers exhibit CDB concentrations of 2–7 µg/l depending on the number of cigarettes smoked
per day (Nordberg and Nordberg 1988), while
CDB levels for those who quit smoking return to general population values (approximately 1 µg/l) within several weeks
(Lauwerys et al. 1976). Based on these observations, Lauwerys et al. (1976) concluded
that CDB has a biological half-life of a few
weeks to less than 3 months. As indicated in
Section 3.1.6, the upper 95th percentile for
CDB levels observed among those who are
not occupationally exposed to cadmium is 5
µg/l, which suggests that the absolute upper
limit to the range reported for smokers by
Nordberg and Nordberg may have been affected by an extreme value (i.e., beyond 2σ
above the mean).
Among occupationally-exposed workers,
the occupational history of exposure to cadmium must be evaluated to interpret CDB
levels. New workers, or workers with low exposures to cadmium, exhibit CDB levels that
are representative of recent exposures, similar to the general population. However, for
workers with a history of chronic exposure
to cadmium, who have accumulated significant stores of cadmium in the kidneys/liver,
part of the CDB concentrations appear to indicate body burden. If such workers are removed from cadmium exposure, their CDB
levels remain elevated, possibly for years, reflecting prior long-term accumulation of
cadmium in body tissues. This condition
tends to occur, however, only beyond some
threshold exposure value, and possibly indicates the capacity of body tissues to accumulate cadmium which cannot be excreted
readily (Friberg and Elinder 1988; Nordberg
and Nordberg 1988).
CDU is widely used as an indicator of cadmium body burdens (Nordberg and Nordberg
1988). CDU is the major route of elimination
and, when CDU is measured, it is commonly
expressed
either
as
µg
Cd/l
urine
(unadjusted), µg Cd/l urine (adjusted for specific gravity), or µg Cd/g CRTU (see Section
5.2.1). The metabolic model for CDU is less
complicated than CDB, since CDU is
dependentin large part on the body (i.e., kidney) burden of cadmium. However, a small
proportion of CDU still be attributed to recent cadmium exposure, particularly if exposure to high airborne concentrations of cadmium occurred. Note that CDU is subject to
larger interindividual and day-to-day variations than CDB, so repeated measurements
are recommended for CDU evaluations.
CDU
is
bound
principally
to
metallothionein, regardless of whether the
cadmium originates from metallothionein in
plasma or from the cadmium pool accumulated in the renal tubules. Therefore, measurement of metallothionein in urine may
provide information similar to CDU, while
avoiding the contamination problems that
190
may occur during collection and handling
urine for cadmium analysis (Nordberg and
Nordberg 1988). However, a commercial
method
for
the
determination
of
metallothionein at the sensitivity levels required under the final cadmium rule is not
currently available; therefore, analysis of
CDU is recommended.
Among the general population not occupationally exposed to cadmium, CDU levels average less than 1 µg/l (see Section 5.2.7). Normalized for creatinine (CRTU), the average
CDU concentration of the general population
is less than 1 µg/g CRTU. As cadmium accumulates over the lifespan, CDU increases
with age. Also, cigarette smokers may eventually accumulate twice the cadmium body
burden of nonsmokers, CDU is slightly higher in smokers than in nonsmokers, even several years after smoking cessation (Nordberg
and Nordberg 1988). Despite variations due to
age and smoking habits, 95% of those not occupationally exposed to cadmium exhibit
levels of CDU less than 3 µg/g CRTU (based
on the data presented in Section 5.2.7).
About 0.02% of the cadmium body burden
is excreted daily in urine. When the critical
cadmium concentration (about 200 ppm) in
the kidney is reached, or if there is sufficient
cadmium-induced kidney dysfunction, dramatic increases in CDU are observed
(Nordberg and Nordberg 1988). Above 200
ppm, therefore, CDU concentrations cease to
be an indicator of cadmium body burden, and
are instead an index of kidney failure.
Proteinuria is an index of kidney dysfunction, and is defined by OSHA to be a material impairment. Several small proteins may
be monitored as markers for proteinuria.
Below levels indicative of proteinuria, these
small proteins may be early indicators of increased risk of cadmium-induced renal tubular disease. Analytes useful for monitoring
cadmium-induced renal tubular damage include:
1. β-2-Microglobulin (B2M), currently the
most widely used assay for detecting kidney
dysfunction, is the best characterized
analyte available (Iwao et al. 1980; Chia et al.
1989);
2. Retinol Binding Protein (RBP) is more
stable than B2M in acidic urine (i.e., B2M
breakdown occurs if urinary pH is less than
5.5; such breakdown may result in false [i.e.,
low] B2M values [Bernard and Lauwerys,
1990]);
3. N-Acetyl-B-Glucosaminidase (NAG) is
the analyte of an assay that is simple, inexpensive, reliable, and correlates with cadmium levels under 10 µg/g CRTU, but the
assay is less sensitive than RBP or B2M
(Kawada et al. 1989);
4. Metallothionein (MT) correlates with
cadmium and B2M levels, and may be a better predictor of cadmium exposure than CDU
and B2M (Kawada et al. 1989);
§ 1910.1027
5. Tamm-Horsfall Glycoprotein (THG) increases slightly with elevated cadmium levels, but this elevation is small compared to
increases in urinary albumin, RBP, or B2M
(Bernard and Lauwerys 1990);
6. Albumin (ALB), determined by the biuret method, is not sufficiently sensitive to
serve as an early indicator of the onset of
renal disease (Piscator 1962);
7. Albumin (ALB), determined by the
Amido Black method, is sensitive and reproducible, but involves a time-consuming procedure (Piscator 1962);
8. Glycosaminoglycan (GAG) increases
among cadmium workers, but the significance of this effect is unknown because no
relationship has been found between elevated
GAG and other indices of tubular damage
(Bernard and Lauwerys 1990);
9. Trehalase seems to increase earlier than
B2M during cadmium exposure, but the procedure for analysis is complicated and unreliable (Iwata et al. 1988); and,
10. Kallikrein is observed at lower concentrations among cadmium-exposed workers than among normal controls (Roels et al.
1990).
Of the above analytes, B2M appears to be
the most widely used and best characterized
analyte to evaluate the presence/absence, as
well as the extent of, cadmium-induced renal
tubular damage (Kawada, Koyama, and Suzuki 1989; Shaikh and Smith 1984; Nogawa
1984). However, it is important that samples
be collected and handled so as to minimize
B2M degradation under acidic urine conditions.
The threshold value of B2MU commonly
used to indicate the presence of kidney damage 300 µg/g CRTU (Kjellstrom et al. 1977a;
Buchet et al. 1980; and Kowal and Zirkes
1983). This value represents the upper 95th or
97.5th percentile level of urinary excretion
observed among those without tubular dysfunction (Elinder, exbt L–140–45, OSHA docket H057A). In agreement with these conclusions, the data presented in Section 5.3.7 of
this protocol generally indicate that the
level of 300 µg/g CRTU appears to define the
boundary for kidney dysfunction. It is not
clear, however, that this level represents the
upper 95th percentile of values observed
among those who fail to demonstrate proteinuria effects.
Although elevated B2MU levels appear to
be a fairly specific indicator of disease associated with cadmium exposure, other conditions that may lead to elevated B2MU levels
include high fevers from influenza, extensive
physical exercise, renal disease unrelated to
cadmium exposure, lymphomas, and AIDS
(Iwao et al. 1980; Schardun and van Epps
1987). Elevated B2M levels observed in association with high fevers from influenza or
from extensive physical exercise are transient, and will return to normal levels once
191
§ 1910.1027
the fever has abated or metabolic rates return to baseline values following exercise.
The other conditions linked to elevated B2M
levels can be diagnosed as part of a properlydesigned
medical
examination.
Consequently, monitoring B2M, when accompanied by regular medical examinations and
CDB and CDU determinations (as indicators
of present and past cadmium exposure), may
serve as a specific, early indicator of cadmium-induced kidney damage.
4.4 Criteria for Medical Monitoring of
Cadmium Workers
Medical monitoring mandated by the final
cadmium rule includes a combination of regular medical examinations and periodic monitoring of 3 analytes: CDB, CDU and B2MU.
As indicated above, CDB is monitored as an
indicator of current cadmium exposure,
while CDU serves as an indicator of the cadmium body burden; B2MU is assessed as an
early marker of irreversible kidney damage
and disease.
The final cadmium rule defines a series of
action levels that have been developed for
each of the 3 analytes to be monitored. These
action levels serve to guide the responsible
physician through a decision-making process. For each action level that is exceeded, a
specific response is mandated. The sequence
of action levels, and the attendant actions,
are described in detail in the final cadmium
rule.
Other criteria used in the medical decision-making process relate to tests performed during the medical examination (including a determination of the ability of a
worker to wear a respirator). These criteria,
however, are not affected by the results of
the analyte determinations addressed in the
above paragraphs and, consequently, will not
be considered further in these guidelines.
4.5
Defining to Quality and Proficiency of
the Analyte Determinations
As noted above in Sections 2 and 3, the
quality of a measurement should be defined
along with its value to properly interpret the
results. Generally, it is necessary to know
the accuracy and the precision of a measurement before it can be properly evaluated.
The precision of the data from a specific laboratory indicates the extent to which the repeated measurements of the same sample
vary within that laboratory. The accuracy of
the data provides an indication of the extent
to which these results deviate from average
results determined from many laboratories
performing the same measurement (i.e., in
the absence of an independent determination
of the true value of a measurement). Note
that terms are defined operationally relative
to the manner in which they will be used in
this protocol. Formal definitions for the
terms in italics used in this section can be
found in the list of definitions (Section 2).
Another data quality criterion required to
properly evaluate measurement results is
the limit of detection of that measurement.
For measurements to be useful, the range of
the measurement which is of interest for biological monitoring purposes must lie entirely above the limit of detection defined
for that measurement.
The overall quality of a laboratory’s results is termed the performance of that laboratory. The degree to which a laboratory
satisfies a minimum performance level is referred to as the proficiency of the laboratory. A successful medical monitoring program, therefore, should include procedures
developed for monitoring and recording laboratory performance; these procedures can
be used to identify the most proficient laboratories.
5.0 Overview of Medical Monitoring Tests
for CDB, CDU, B2MU and CRTU
To evaluate whether available methods for
assessing CDB, CDU, B2MU and CRTU are
adequate for determining the parameters defined by the proposed action levels, it is necessary to review procedures available for
sample collection, preparation and analysis.
A variety of techniques for these purposes
have been used historically for the determination of cadmium in biological matrices
(including CDB and CDU), and for the determination of specific proteins in biological
matrices (including B2MU). However, only
the most recent techniques are capable of
satisfying the required accuracy, precision
and sensitivity (i.e., limit of detection) for
monitoring at the levels mandated in the
final cadmium rule, while still facilitating
automated analysis and rapid processing.
5.1
Measuring Cadmium in Blood (CDB)
Analysis of biological samples for cadmium requires strict analytical discipline regarding collection and handling of samples.
In addition to occupational settings, where
cadmium contamination would be apparent,
cadmium is a ubiquitous environmental contaminant, and much care should be exercised
to ensure that samples are not contaminated
during collection, preparation or analysis.
Many common chemical reagents are contaminated with cadmium at concentrations
that will interfere with cadmium analysis;
because of the widespread use of cadmium
compounds as colored pigments in plastics
and coatings, the analyst should continually
monitor each manufacturer’s chemical reagents and collection containers to prevent
contamination of samples.
Guarding against cadmium contamination
of biological samples is particularly important when analyzing blood samples because
cadmium concentrations in blood samples
192
from nonexposed populations are generally
less than 2 µg/l (2 ng/ml), while occupationally-exposed workers can be at medical risk
to cadmium toxicity if blood concentrations
exceed 5 µg/l (ACGIH 1991 and 1992). This narrow margin between exposed and unexposed
samples requires that exceptional care be
used in performing analytic determinations
for biological monitoring for occupational
cadmium exposure.
Methods for quantifying cadmium in blood
have improved over the last 40 years primarily because of improvements in analyt-
§ 1910.1027
ical instrumentation. Also, due to improvements in analytical techniques, there is less
need to perform extensive multi-step sample
preparations prior to analysis. Complex sample preparation was previously required to
enhance method sensitivity (for cadmium),
and to reduce interference by other metals
or components of the sample.
5.1.1 Analytical Techniques Used to
Monitor Cadmium in Biological Matrices
TABLE 3—COMPARISON OF ANALYTICAL PROCEDURES/INSTRUMENTATION FOR DETERMINATION OF
CADMIUM IN BIOLOGICAL SAMPLES
Analytical procedure
Flame Atomic Absorption Spectroscopy (FAAS).
Graphite Furnace
Atomic Absorption Spectroscopy (GFAAS).
Inductively-Coupled Argon-Plasma Atomic
Emission Spectroscopy (ICAP
AES).
Neutron Activation
Gamma Spectroscopy (NA).
Isotope Dilution
Mass Spectroscopy (IDMS).
Differential Pulse
Anodic Stripping
Voltammetry
(DPASV).
Limit of detection [ng/(g or
ml)]
≥1.0
Specified biological matrix
Reference
Any matrix ...........
Perkin-Elmer
(1982).
0.04
Urine ....................
Pruszkowska et
al. (1983).
≥0.20
Blood ...................
2.0
Stoeppler and
Brandt (1980).
NIOSH (1984A) ...
1.5
In vivo (liver) ........
Ellis et al. (1983)
<1.0
<1.0
Comments
Not sensitive enough for biomonitoring without
extensive sample digestion, metal chelation
and organic solvent extraction.
Methods of choice for routine cadmium analysis.
Requires extensive sample preparation and
concentration of metal with chelating resin.
Advantage is simultaneous analyses for as
many as 10 metals from 1 sample.
Only available in vivo method for direct determination of cadmium body tissue burdens;
expensive; absolute determination of cadmium in reference materials.
Michiels and
Suitable for absolute determination of cadDeBievre (1986).
mium in reference materials; expensive.
Stoeppler and
Brandt (1980).
A number of analytical techniques have
been used for determining cadmium concentrations in biological materials. A summary of the characteristics of the most widely employed techniques is presented in Table
3. The technique most suitable for medical
monitoring for cadmium is atomic absorption spectroscopy (AAS).
To obtain a measurement using AAS, a
light source (i.e., hollow cathode or lectrodefree discharge lamp) containing the element
of interest as the cathode, is energized and
the lamp emits a spectrum that is unique for
that element. This light source is focused
through a sample cell, and a selected wavelength is monitored by a monochrometer and
photodetector cell. Any ground state atoms
in the sample that match those of the lamp
element and are in the path of the emitted
light may absorb some of the light and decrease the amount of light that reaches the
Suitable for absolute determination of cadmium in reference materials; efficient method to check accuracy of analytical method.
photodetector cell. The amount of light absorbed at each characteristic wavelength is
proportional to the number of ground state
atoms of the corresponding element that are
in the pathway of the light between the
source and detector.
To determine the amount of a specific metallic element in a sample using AAS, the
sample is dissolved in a solvent and aspirated into a high-temperature flame as an
aerosol. At high temperatures, the solvent is
rapidly evaporated or decomposed and the
solute is initially solidified; the majority of
the sample elements then are transformed
into an atomic vapor. Next, a light beam is
focused above the flame and the amount of
metal in the sample can be determined by
measuring the degree of absorbance of the
atoms of the target element released by the
flame at a characteristic wavelength.
193
§ 1910.1027
A more refined atomic absorption technique, flameless AAS, substitutes an
electrothermal, graphite furnace for the
flame. An aliquot (10–100 µl) of the sample is
pipetted into the cold furnace, which is then
heated rapidly to generate an atomic vapor
of the element.
AAS is a sensitive and specific method for
the elemental analysis of metals; its main
drawback
is
nonspecific
background
absorbtion and scattering of the light beam
by particles of the sample as it decomposes
at high temperatures; nonspecific absorbance reduces the sensitivity of the analytical
method. The problem of nonspecific absorbance and scattering can be reduced by extensive sample pretreatment, such as ashing
and/or acid digestion of the sample to reduce
its organic content.
Current AAS instruments employ background correction devices to adjust electronically for background absorbtion and
scattering. A common method to correct for
background effects is to use a deuterium arc
lamp as a second light source. A continuum
light source, such as the deuterium lamp,
emits a broad spectrum of wavelengths instead of specific wavelengths characteristic
of a particular element, as with the hollow
cathode tube. With this system, light from
the primary source and the continuum
source are passed alternately through the
sample cell. The target element effectively
absorbs light only from the primary source
(which is much brighter than the continuum
source at the characteristic wavelengths),
while the background matrix absorbs and
scatters light from both sources equally.
Therefore, when the ratio of the two beams
is measured electronically, the effect of nonspecific background absorption and scattering is eliminated. A less common, but
more sophisticated, backgrond correction
system is based on the Zeeman effect, which
uses a magnetically-activated light polarizer
to compensate electronically for nonspecific
absorbtion and scattering.
Atomic emission spectroscopy with inductively-coupled argon plasma (AES–ICAP) is
widely used to analyze for metals. With this
instrument, the sample is aspirated into an
extremely hot argon plasma flame, which excites the metal atoms; emission spectra specific for the sample element then are generated. The quanta of emitted light passing
through a monochrometer are amplified by
photomultiplier tubes and measured by a
photodetector to determine the amount of
metal in the sample. An advantage of AES–
ICAP over AAS is that multi-elemental analyses of a sample can be performed by simultaneously measuring specific elemental
emission energies. However, AES–ICAP lacks
the sensitivity of AAS, exhibiting a limit of
detection which is higher than the limit of
detection for graphite-furnace AAS (Table 3).
Neutron activation (NA) analysis and isotope dilution mass spectrometry (IDMS) are
2 additional, but highly specialized, methods
that have been used for cadmium determinations. These methods are expensive because
they require elaborate and sophisticated instrumentation.
NA analysis has the distinct advantage
over other analytical methods of being able
to determine cadmium body burdens in specific organs (e.g., liver, kidney) in vivo (Ellis
et al. 1983). Neutron bombardment of the target transforms cadmium-113 to cadmium-114,
which promptly decays (<10¥14 sec) to its
ground state, emitting gamma rays that are
measured using large gamma detectors; appropriate shielding and instrumentation are
required when using this method.
IDMS analysis, a definitive but laborious
method, is based on the change in the ratio
of 2 isotopes of cadmium (cadmium 111 and
112) that occurs when a known amount of the
element (with an artificially altered ratio of
the same isotopes [i.e., a cadmium 111
‘‘spike’’] is added to a weighed aliquot of the
sample (Michiels and De Bievre 1986).
5.1.2
Methods Developed for CDB
Determinations
A variety of methods have been used for
preparing and analyzing CDB samples; most
of these methods rely on one of the analytical techniques described above. Among the
earliest reports, Princi (1947) and Smith et
al. (1955) employed a colorimetric procedure
to analyze for CDB and CDU. Samples were
dried and digested through several cycles
with concentrated mineral acids (HNO3 and
H2 SO4) and hydrogen peroxide (H2 O2). The
digest was neutralized, and the cadmium was
complexed with diphenylthiocarbazone and
extracted with chloroform. The dithizonecadmium complex then was quantified using
a spectrometer.
Colorimetric procedures for cadmium analyses were replaced by methods based on
atomic absorption spectroscopy (AAS) in the
early 1960s, but many of the complex sample
preparation
procedures
were
retained.
Kjellstrom (1979) reports that in Japanese,
American and Swedish laboratories during
the early 1970s, blood samples were wet ashed
with mineral acids or ashed at high temperature and wetted with nitric acid. The cadmium in the digest was complexed with
metal
chelators
including
diethyl
dithiocarbamate (DDTC), ammonium pyrrolidine
dithiocarbamate
(APDC)
or
diphenylthiocarbazone (dithizone) in ammonia-citrate buffer and extracted with methyl
isobutyl ketone (MIBK). The resulting solution then was analyzed by flame AAS or
graphite-furnace AAS forcadmium determinations using deuterium-lamp background
correction.
In the late 1970s, researchers began developing simpler preparation procedures. Roels
194
et al. (1978) and Roberts and Clark (1986) developed simplified digestion procedures.
Using the Roberts and Clark method, a 0.5
ml aliquot of blood is collected and transferred to a digestion tube containing 1 ml
concentrated HNO3. The blood is then digested at 110 °C for 4 hours. The sample is reduced in volume by continued heating, and
0.5 ml 30% H2 O2 is added as the sample dries.
The residue is dissolved in 5 ml dilute (1%)
HNO3, and 20 µl of sample is then analyzed by
graphite-furnace AAS with deuterium-background correction.
The current trend in the preparation of
blood samples is to dilute the sample and add
matrix modifiers to reduce background interference, rather than digesting the sample
to reduce organic content. The method of
Stoeppler and Brandt (1980), and the abbreviated procedure published in the American
Public Health Association’s (APHA) Methods
for Biological Monitoring (1988), are straightforward and are nearly identical. For the
APHA method, a small aliquot (50–300 µ l) of
whole blood that has been stabilized with
ethylenediaminetetraacetate
(EDTA)
is
added to 1.0 ml 1MHNO3, vigorously shaken
and centrifuged. Aliquots (10–25 µ l) of the supernatant then are then analyzed by graphite-furnace AAS with appropriate background correction.
Using the method of Stoeppler and Brandt
(1980), aliquots (50–200 µ l) of whole blood
that have been stabilized with EDTA are
pipetted into clean polystyrene tubes and
mixed with 150-600 µ l of 1 M HNO3. After vigorous shaking, the solution is centrifuged
and a 10–25 µ l aliquot of the supernatant
then is analyzed by graphite-furnace AAS
with appropriate background correction.
Claeys-Thoreau (1982) and DeBenzo et al.
(1990) diluted blood samples at a ratio of 1:10
with a matrix modifier (0.2% Triton X–100, a
wetting agent) for direct determinations of
CDB. DeBenzo et al. also demonstrated that
aqueous standards of cadmium, instead of
spiked, whole-blood samples, could be used
to establish calibration curves if standards
and samples are treated with additional
small volumes of matrix modifiers (i.e., 1%
HNO3, 0.2% ammonium hydrogenphosphate
and 1 mg/ml magnesium salts).
These direct dilution procedures for CDB
analysis are simple and rapid. Laboratories
can process more than 100 samples a day
using a dedicated graphite-furnace AAS, an
auto-sampler, and either a Zeeman- or a deuterium-background correction system. Several authors emphasize using optimum settings for graphite-furnace temperatures during the drying, charring, and atomization
processes associated with the flameless AAS
method, and the need to run frequent QC
samples when performing automated analysis.
5.1.3
§ 1910.1027
Sample Collection and Handling
Sample collection procedures are addressed
primarily to identify ways to minimize the
degree of variability that may be introduced
by sample collection during medical monitoring. It is unclear at this point the extent
to which collection procedures contribute to
variability among CDB samples. Sources of
variation that may result from sampling
procedures include time-of-day effects and
introduction of external contamination during the collection process. To minimize these
sources, strict adherence to a sample collection protocol is recommended. Such a protocol must include provisions for thorough
cleaning of the site from which blood will be
extracted; also, every effort should be made
to collect samples near the same time of day.
It is also important to recognize that under
the recent OSHA blood-borne pathogens
standard (29 CFR 1910.1030), blood samples
and certain body fluids must be handled and
treated as if they are infectious.
5.1.4 Best Achievable Performance
The best achievable performance using a
particular method for CDB determinations is
assumed to be equivalent to the performance
reported by research laboratories in which
the method was developed.
For their method, Roberts and Clark (1986)
demonstrated a limit of detection of 0.4 µg
Cd/l in whole blood, with a linear response
curve from 0.4 to 16.0 µg Cd/l. They report a
coefficient of variation (CV) of 6.7% at 8.0 µg/
l.
The APHA (1988) reports a range of 1.0–25
µg/l, with a CV of 7.3% (concentration not
stated). Insufficient documentation was
available to critique this method.
Stoeppler and Brandt (1980) achieved a detection limit of 0.2 µg Cd/l whole blood, with
a linear range of 0.4–12.0 µg Cd/l, and a CV of
15–30%, for samples at <1.0 µg/l. Improved
precision (CV of 3.8%) was reported for CDB
concentrations at 9.3 µg/l.
5.1.5
General Method Performance
For any particular method, the performance expected from commercial laboratories
may be somewhat lower than that reported
by the research laboratory in which the
method was developed. With participation in
appropriate proficiency programs and use of
a proper in-house QA/QC program incorporating provisions for regular corrective actions, the performance of commercial laboratories is expected to approach that reported
by research laboratories. Also, the results reported for existing proficiency programs
serve as a gauge of the likely level of performance that currently can be expected
from commercial laboratories offering these
analyses.
Weber (1988) reports on the results of the
proficiency program run by the Centre de
195
§ 1910.1027
Toxicologie du Quebec (CTQ). As indicated
previously, participants in that program receive 18 blood samples per year having cadmium concentrations ranging from 0.2–20 µg/
l. Currently, 76 laboratories are participating
in this program. The program is established
for several analytes in addition to cadmium,
and not all of these laboratories participate
in the cadmium proficiency-testing program.
Under the CTQ program, cadmium results
from individual laboratories are compared
against the consensus mean derived for each
sample. Results indicate that after receiving
60 samples (i.e., after participation for approximately three years), 60% of the laboratories in the program are able to report results that fall within ±1 µg/l or 15% of the
mean, whichever is greater. (For this procedure, the 15% criterion was applied to concentrations exceeding 7 µg/l.) On any single
sample of the last 20 samples, the percentage
of laboratories falling within the specified
range is between 55 and 80%.
The CTQ also evaluates the performance of
participating laboratories against a less severe standard: ±2 µg/l or 15% of the mean,
whichever is greater (Weber 1988); 90% of participating laboratories are able to satisfy
this standard after approximately 3 years in
the program. (The 15% criterion is used for
concentrations in excess of 13 µg/l.) On any
single sample of the last 15 samples, the percentage of laboratories falling within the
specified range is between 80 and 95% (except
for a single test for which only 60% of the
laboratories achieved the desired performance).
Based on the data presented in Weber
(1988), the CV for analysis of CDB is nearly
constant at 20% for cadmium concentrations
exceeding 5 µg/l, and increases for cadmium
concentrations below 5 µg/l. At 2 µg/l, the reported CV rises to approximately 40%. At 1
µg/l, the reported CV is approximately 60%.
Participating laboratories also tend to
overestimate concentrations for samples exhibiting concentrations less than 2 µg/l (see
Figure 11 of Weber 1988). This problem is due
in part to the proficiency evaluation criterion that allows reporting a minimum ±2.0
µg/l for evaluated CDB samples. There is currently little economic or regulatory incentive for laboratories participating in the
CTQ program to achieve greater accuracy for
CDB samples containing cadmium at concentrations less than 2.0 µg/l, even if the laboratory has the experience and competency
to distinguish among lower concentrations
in the samples obtained from the CTQ.
The collective experience of international
agencies and investigators demonstrate the
need for a vigorous QC program to ensure
that CDB values reported by participating
laboratories are indeed reasonably accurate.
As Friberg (1988) stated:
‘‘Information about the quality of published
data has often been lacking. This is of con-
cern as assessment of metals in trace concentrations in biological media are fraught
with difficulties from the collection, handling, and storage of samples to the chemical
analyses. This has been proven over and over
again from the results of interlaboratory
testing and quality control exercises. Large
variations in results were reported even from
‘experienced’ laboratories.’’
The UNEP/WHO global study of cadmium
biological monitoring set a limit for CDB accuracy using the maximum allowable deviation method at Y=X±(0.1X+1) for a targeted
concentration of 10 µg Cd/l (Friberg and
Vahter 1983). The performance of participating laboratories over a concentration
range of 1.5–12 µg/l was reported by Lind et
al. (1987). Of the 3 QC runs conducted during
1982 and 1983, 1 or 2 of the 6 laboratories
failed each run. For the years 1983 and 1985,
between zero and 2 laboratories failed each of
the consecutive QC runs.
In another study (Vahter and Friberg 1988),
QC samples consisting of both external (unknown) and internal (stated) concentrations
were distributed to laboratories participating in the epidemiology research. In this
study, the maximum acceptable deviation
between the regression analysis of reported
results and reference values was set at
Y=X±(0.05X+0.2) for a concentration range of
0.3–5.0 µg Cd/l. It is reported that only 2 of 5
laboratories had acceptable data after the
first QC set, and only 1 of 5 laboratories had
acceptable data after the second QC set. By
the fourth QC set, however, all 5 laboratories
were judged proficient.
The need for high quality CDB monitoring
is apparent when the toxicological and biological characteristics of this metal are considered; an increase in CDB from 2 to 4 µg/l
could cause a doubling of the cadmium accumulation in the kidney, a critical target tissue for selective cadmium accumulation
(Nordberg and Nordberg 1988).
Historically, the CDC’s internal QC program for CDB cadmium monitoring program
has found achievable accuracy to be ±10% of
the true value at CDB concentrations ≥5.0 µg/
l (Paschal 1990). Data on the performance of
laboratories participating in this program
currently are not available.
5.1.6
Observed CDB Concentrations
As stated in Section 4.3, CDB concentrations are representative of ongoing levels of
exposure to cadmium. Among those who
have been exposed chronically to cadmium
for extended periods, however, CDB may contain a component attributable to the general
cadmium body burden.
5.1.6.1 CDB Concentrations Among Unexposed
Samples
Numerous studies have been conducted examining CDB concentrations in the general
196
population, and in control groups used for
comparison with cadmium-exposed workers.
A number of reports have been published
that present erroneously high values of CDB
(Nordberg and Nordberg 1988). This problem
was due to contamination of samples during
sampling and analysis, and to errors in analysis. Early AAS methods were not sufficiently sensitive to accurately estimate CDB
concentrations.
§ 1910.1027
Table 4 presents results of recent studies
reporting CDB levels for the general U.S.
population not exposed occupationally to
cadmium. Other surveys of tissue cadmium
using U.S. samples and conducted as part of
a cooperative effort among Japan, Sweden
and the U.S., did not collect CDB data because standard analytical methodologies
were unavailable, and because of analytic
problems (Kjellstrom 1979; SWRI 1978).
197
M
F
M/F
M/F
M
M
M
F
F
M
M
20
64
39
32
35
Sex
80
88
115
31
10
24
No. in
study (n)
Adults
Adults
Adults
Adults
Adults
.............
.............
.............
.............
.............
4 to 69 ...........
4 to 69 ...........
4 to 69 ...........
4 to 69 ...........
Adults .............
Adults .............
Age
c
b
a
Concentrations reported in µg Cd/l blood unless otherwise stated.
NS—never smoked; S—current cigarette smoker.
S.D.—Arithmetic Standard Deviation.
d C.I.—Confidence interval.
e GSD—Geometric Standard Deviation.
f Based on an assumed lognormal distribution.
g Based on an assumed normal distribution.
4 .................................................
5 .................................................
2 .................................................
3 .................................................
1 .................................................
Study No.
S
NS
S
S,NS
(?)
NS,S
NS,S
NS
S
(?)
NS
Smoking
habits b
2.1±2.1
1.13
1.03
0.95
1.54
2.0±2.1
Arithmetic
mean (±
S.D.) c
(0.5–7.3)
0.35–3.3
0.21–3.3
0.21–3.3
0.4–3.3
(0.5–5.0)
Absolute
range or
(95% CI) d
1.2±2.13
0.5±1.85
0.8±2.22
1.2±2.0
0.6±1/87
0.98±1.71
0.91±1.63
0.85±1.59
1.37±1.65
Geometric
mean (±
GSD) e
0.3
0.2
0.2
0.4
g (0)
0.4
0.4
0.4
0.6
g (0)
0.2
Lower 95th
percentile of
distribution f
4.4
1.4
3.1
3.9
g (5.6)
2.4
2.0
1.8
3.2
g (5.8)
1.8
Upper 95th
percentile of
distribution f
Reference
Thun et al. (1989).
Mueller et al. (1989).
Ellis et al. (1983).
Frieberg and Vahter
(1983).
Kowal et al. (1979).
TABLE 4—BLOOD CADMIUM CONCENTRATIONS OF U.S. POPULATION NOT OCCUPATIONALLY EXPOSED TO CADMIUM a
§ 1910.1027
198
Arithmetic and/or geometric means and
standard deviations are provided in Table 4
for measurements among the populations defined in each study listed. The range of reported measurements and/or the 95% upper
and lower confidence intervals for the means
are presented when this information was reported in a study. For studies reporting either an arithmetic or geometric standard deviation along with a mean, the lower and
upper 95th percentile for the distribution
also were derived and reported in the table.
The data provided in table 4 from Kowal et
al. (1979) are from studies conducted between
1974 and 1976 evaluating CDB levels for the
general population in Chicago, and are considered to be representative of the U.S. population. These studies indicate that the average CDB concentration among those not occupationally exposed to cadmium is approximately 1 µg/l.
In several other studies presented in Table
4, measurements are reported separately for
males and females, and for smokers and nonsmokers. The data in this table indicate that
similar CDB levels are observed among
males and females in the general population,
but that smokers tend to exhibit higher CDB
levels than nonsmokers. Based on the Kowal
et al. (1979) study, smokers not occupationally exposed to cadmium exhibit an average
CDB level of 1.4 µg/l.
In general, nonsmokers tend to exhibit levels ranging to 2 µg/l, while levels observed
among smokers range to 5 µg/l. Based on the
data presented in Table 4, 95% of those not
occupationally exposed to cadmium exhibit
CDB levels less than 5 µg/l.
5.1.6.2
§ 1910.1027
CDB concentrations among exposed
workers
Table 5 is a summary of results from studies reporting CDB levels among workers exposed to cadmium in the work place. As in
Table 4, arithmetic and/or geometric means
and standard deviations are provided if reported in the listed studies. The absolute
range, or the 95% confidence interval around
the mean, of the data in each study are provided when reported. In addition, the lower
and upper 95th percentile of the distribution
are presented for each study i which a mean
and corresponding standard deviation were
reported. Table 5 also provides estimates of
the duration, and level, of exposure to cadmium in the work place if these data were
reported in the listed studies. The data presented in table 5 suggest that CDB levels are
dose related. Sukuri et al. (1983) show that
higher CDB levels are observed among workers experiencing higher work place exposure.
This trend appears to be true of the studies
listed in the table.
CDB levels reported in table 5 are higher
among those showing signs of cadmium-related kidney damage than those showing no
such damage. Lauwerys et al. (1976) report
CDB levels among workers with kidney lesions that generally are above the levels reported for workers without kidney lesions.
Ellis et al. (1983) report a similar observation
comparing workers with and without renal
dysfunction, although they found more overlap between the 2 groups than Lauwerys et
al.
199
200
......................
10–34
Up to 39
(19.0)
18
75
45
40
1–34
(27.2)
g(4.2)
..............
..............
33
(10.6)
(7.3)
15–41
c
b
a
(5)
(9)
......................
......................
3–40
Employment
in years
(mean)
7
9
19
7
8
96
25
Number
in study
Concentrations reported in µg Cd/l blood unless otherwise stated.
S.D.—Standard Deviation.
C.I.—Confidence Interval.
d GSD—Geometric Standard Deviation.
e Based on an assumed lognormal distribution.
f Based on an assumed normal distribution.
g Years following removal.
8 .............
6 .............
7 .............
5 .............
4 .............
3 .............
(Smokers) ..........................................
(Nonsmokers) ....................................
Cadmium alloy plant:
(High exposure group) ...................
(Low exposure group) ...................
Retrospective study of workers with
renal problems:
(Before removal) ............................
(After removal) ...............................
Cadmium production plant:
(Workers without renal dysfunction).
(Workers with renal dysfunction) ...
Cd-Cu alloy plant ..............................
Cadmium recovery operation—Current (19) and former (26) workers.
Cadmium recovery operation
Ni-Cd battery plant and Cd production plant:
(Workers without kidney lesions) ..
(Workers with kidney lesions) .......
Ni-Cd battery plant:
1 .............
2 .............
Work environment (worker population monitored)
Study
number
..........................
..........................
..........................
..........................
..........................
..........................
..........................
[1,000–5 yrs;
40–5 yrs]
10.1
7.0
..........................
..........................
≤90
Mean concentration of
cadmium in air
(µg/m 3)
10.2±5.3
24±8.5
....................
....................
15±5.7
39.9±3.7
14.1±5.6
20.8±7.1
7.1±1.1
22.7
7.0
21.4±1.9
38.8±3.8
Arithmetic
mean (±
S.D.) b
2.2–18.8
10–34
..................
..................
7–31
11–179
5.7–27.4
..................
..................
7.3–67.2
4.9–10.5
..................
..................
Absolute
range or
(95% C.I.) c
..................
..................
8.8±1.1
7.9±2.0
..................
..................
..................
..................
..................
..................
..................
Geometric
mean
(GSD)d
(1.3)
(9.3)
7.5
2.5
(5.4)
(34)
(4.4)
(7.3)
(5.1)
(18)
(32)
Lower 95th
percentile of
range e
( )f
(19)
(39)
10
25
(25)
(46)
(24)
(34)
(9.1)
....................
(25)
(45)
Upper 95th
percentile of
range e
( )f
Concentrations of Cadmium in blood a
TABLE 5—BLOOD CADMIUM IN WORKERS EXPOSED TO CADMIUM IN THE WORKPLACE
Mueller et al.
1989.
Mason et al. 1988.
Thun et al. 1989.
Ellis et al. 1983.
Roels et al. 1982.
Sukuri et al. 1982.
Adamsson et al.
(1979).
Lauwerys et al.
1976.
Reference
§ 1910.1027
The data in table 5 also indicate that CDB
levels are higher among those experiencing
current occupational exposure than those
who have been removed from such exposure.
Roels et al. (1982) indicate that CDB levels
observed among workers experiencing ongoing exposure in the work place are almost
entirely above levels observed among workers removed from such exposure. This finding
suggests that CDB levels decrease once cadmium exposure has ceased.
A comparison of the data presented in tables 4 and 5 indicates that CDB levels observed among cadmium-exposed workers is
significantly higher than levels observed
among the unexposed groups. With the exception of 2 studies presented in table 5 (1 of
which includes former workers in the sample
group tested), the lower 95th percentile for
CDB levels among exposed workers are
greater than 5 µg/l, which is the value of the
upper 95th percentile for CDB levels observed
among those who are not occupationally exposed. Therefore, a CDB level of 5 µg/l represents a threshold above which significant
work place exposure to cadmium may be occurring.
5.1.7
Conclusions and Recommendations for
CDB
Based on the above evaluation, the following recommendations are made for a CDB
proficiency program.
5.1.7.1
Recommended method
The method of Stoeppler and Brandt (1980)
should be adopted for analyzing CDB. This
method was selected over other methods for
its straightforward sample-preparation procedures, and because limitations of the
method were described adequately. It also is
the method used by a plurality of laboratories currently participating in the CTQ
proficiency program. In a recent CTQ interlaboratory comparison report (CTQ 1991),
analysis of the methods used by laboratories
to measure CDB indicates that 46% (11 of 24)
of the participating laboratories used the
Stoeppler and Brandt methodology (HNO3
deproteinization of blood followed by analysis of the supernatant by GF-AAS). Other
CDB methods employed by participating laboratories identified in the CTQ report include dilution of blood (29%), acid digestion
(12%) and miscellaneous methods (12%).
Laboratories may adopt alternate methods, but it is the responsibility of the laboratory to demonstrate that the alternate
methods meet the data quality objectives defined for the Stoeppler and Brandt method
(see Section 5.1.7.2 below).
5.1.7.2
Data quality objectives
Based on the above evaluation, the following data quality objectives (DQOs) should
§ 1910.1027
facilitate interpretation of analytical results.
Limit of Detection. 0.5 µg/l should be achievable using the Stoeppler and Brandt method.
Stoeppler and Brandt (1980) report a limit of
detection equivalent to ≤0.2 µg/l in whole
blood using 25 µ l aliquots of deproteinized,
diluted blood samples.
Accuracy. Initially, some of the laboratories performing CDB measurements may
be expected to satisfy criteria similar to the
less severe criteria specified by the CTQ program, i.e., measurements within 2 µg/l or 15%
(whichever is greater) of the target value.
About 60% of the laboratories enrolled in the
CTQ program could meet this criterion on
the first proficiency test (Weber 1988).
Currently, approximately 12 laboratories
in the CTQ program are achieving an accuracy for CDB analysis within the more severe constraints of ±1 µg/l or 15% (whichever
is greater). Later, as laboratories gain experience, they should achieve the level of accuracy exhibited by these 12 laboratories. The
experience in the CTQ program has shown
that, even without incentives, laboratories
benefit from the feedback of the program;
after they have analyzed 40–50 control samples from the program, performance improves to the point where about 60% of the
laboratories can meet the stricter criterion
of ±1 µg/l or 15% (Weber 1988). Thus, this
stricter target accuracy is a reasonable DQO.
Precision. Although Stoeppler and Brandt
(1980) suggest that a coefficient of variation
(CV) near 1.3% (for a 10 µg/l concentration) is
achievable for within-run reproducibility, it
is recognized that other factors affecting
within- and between-run comparability will
increase the achievable CV. Stoeppler and
Brandt (1980) observed CVs that were as high
as 30% for low concentrations (0.4 µg/l), and
CVs of less than 5% for higher concentrations.
For internal QC samples (see Section 3.3.1),
laboratories should attain an overall precision near 25%. For CDB samples with concentrations less than 2 µg/l, a target precision of 40% is reasonable, while precisions of
20% should be achievable for concentrations
greater than 2 µg/l. Although these values
are more strict than values observed in the
CTQ interlaboratory program reported by
Webber (1988), they are within the achievable
limits reported by Stoeppler and Brandt
(1980).
5.1.7.3 Quality assurance/quality control
Commercial laboratories providing measurement of CDB should adopt an internal
QA/QC program that incorporates the following components: Strict adherence to the
selected method, including all calibration requirements; regular incorporation of QC
samples during actual runs; a protocol for
corrective actions, and documentation of
201
§ 1910.1027
these actions; and, participation in an interlaboratory proficiency program. Note that
the nonmandatory QA/QC program presented
in Attachment 1 is based on the Stoeppler
and Brandt method for CDB analysis. Should
an alternate method be adopted, the laboratory should develop a QA/QC program satisfying the provisions of Section 3.3.1.
5.2 Measuring Cadmium in Urine (CDU)
As in the case of CDB measurement, proper
determination of CDU requires strict analytical discipline regarding collection and handling of samples. Because cadmium is both
ubiquitous in the environment and employed
widely in coloring agents for industrial products that may be used during sample collection, preparation and analysis, care should
be exercised to ensure that samples are not
contaminated during the sampling procedure.
Methods for CDU determination share
many of the same features as those employed
for the determination of CDB. Thus, changes
and improvements to methods for measuring
CDU over the past 40 years parallel those
used to monitor CDB. The direction of development has largely been toward the simplification of sample preparation techniques
made possible because of improvements in
analytic techniques.
5.2.1
Units of CDU Measurement
Procedures adopted for reporting CDU concentrations are not uniform. In fact, the situation for reporting CDU is more complicated than for CDB, where concentrations
are normalized against a unit volume of
whole blood.
Concentrations of solutes in urine vary
with several biological factors (including the
time since last voiding and the volume of
liquid consumed over the last few hours); as
a result, solute concentrations should be
normalized against another characteristic of
urine that represents changes in solute concentrations. The 2 most common techniques
are either to standardize solute concentrations against the concentration of creatinine, or to standardize solute concentrations
against the specific gravity of the urine.
Thus, CDU concentrations have been reported in the literature as ‘‘uncorrected’’
concentrations of cadmium per volume of
urine (i.e., µg Cd/l urine), ‘‘corrected’’ concentrations of cadmium per volume of urine
at a standard specific gravity (i.e., µg Cd/l
urine at a specific gravity of 1.020), or ‘‘corrected’’ mass concentration per unit mass of
creatinine (i.e., µg Cd/g creatinine). (CDU
concentrations [whether uncorrected or corrected for specific gravity, or normalized to
creatinine] occasionally are reported in
nanomoles [i.e., nmoles] of cadmium per unit
mass or volume. In this protocol, these values are converted to µg of cadmium per unit
mass or volume using 89 nmoles of
cadmium=10 µg.)
While it is agreed generally that urine values of analytes should be normalized for reporting purposes, some debate exists over
what correction method should be used. The
medical community has long favored normalization based on creatinine concentration, a common urinary constituent. Creatinine is a normal product of tissue catabolism, is excreted at a uniform rate, and the
total amount excreted per day is constant on
a day-to-day basis (NIOSH 1984b). While this
correction method is accepted widely in Europe, and within some occupational health
circles, Kowals (1983) argues that the use of
specific gravity (i.e., total solids per unit
volume) is more straightforward and practical (than creatinine) in adjusting CDU values for populations that vary by age or gender.
Kowals (1983) found that urinary creatinine
(CRTU) is lower in females than males, and
also varies with age. Creatinine excretion is
highest in younger males (20–30 years old),
decreases at middle age (50–60 years), and
may rise slightly in later years. Thus, cadmium concentrations may be underestimated for some workers with high CRTU levels.
Within a single void urine collection, urine
concentration of any analyte will be affected
by recent consumption of large volumes of
liquids, and by heavy physical labor in hot
environments. The absolute amount of
analyte excreted may be identical, but concentrations will vary widely so that urine
must be corrected for specific gravity (i.e.,
to normalize concentrations to the quantity
of total solute) using a fixed value (e.g., 1.020
or 1.024). However, since heavy-metal exposure may increase urinary protein excretion,
there is a tendency to underestimate cadmium concentrations in samples with high
specific gravities when specific-gravity corrections are applied.
Despite some shortcomings, reporting solute concentrations as a function of creatinine concentration is accepted generally;
OSHA therefore recommends that CDU levels
be reported as the mass of cadmium per unit
mass of creatinine (µg/g CTRU).
Reporting CDU as µg/g CRTU requires an
additional analytical process beyond the
analysis of cadmium: Samples must be analyzed independently for creatinine so that results may be reported as the ratio of cadmium to creatinine concentrations found in
the urine sample. Consequently, the overall
quality of the analysis depends on the combined performance by a laboratory on these
2 determinations. The analysis used for CDU
determinations is addressed below in terms
of µg Cd/l, with analysis of creatinine addressed separately. Techniques for assessing
creatinine are discussed in Section 5.4.
202
Techniques for deriving cadmium as a
ratio of CRTU, and the confidence limits for
independent measurements of cadmium and
CRTU, are provided in Section 3.3.3.
5.2.2
Analytical Techniques Used to
Monitor CDU
Analytical techniques used for CDU determinations are similar to those employed for
CDB determinations; these techniques are
summarized in Table 3. As with CDB monitoring, the technique most suitable for CDU
determinations is atomic absorption spectroscopy (AAS). AAS methods used for CDU
determinations typically employ a graphite
furnace, with background correction made
using either the deuterium-lamp or Zeeman
techniques; Section 5.1.1 provides a detailed
description of AAS methods.
5.2.3
Methods Developed for CDU
Determinations
Princi (1947), Smith et al. (1955), Smith and
Kench (1957), and Tsuchiya (1967) used colorimetric procedures similar to those described
in the CDB section above to estimate CDU
concentrations. In these methods, urine (50
ml) is reduced to dryness by heating in a
sand bath and digested (wet ashed) with mineral acids. Cadmium then is complexed with
dithiazone, extracted with chloroform and
quantified by spectrophotometry. These
early studies typically report reagent blank
values equivalent to 0.3 µg Cd/l, and CDU
concentrations among nonexposed control
groups at maximum levels of 10 µg Cd/l— erroneously high values when compared to
more recent surveys of cadmium concentrations in the general population.
By the mid-1970s, most analytical procedures for CDU analysis used either wet
ashing (mineral acid) or high temperatures
(>400 °C) to digest the organic matrix of
urine, followed by cadmium chelation with
APDC or DDTC solutions and extraction
with MIBK. The resulting aliquots were analyzed by flame or graphite-furnace AAS
(Kjellstrom 1979).
Improvements in control over temperature
parameters with electrothermal heating devices used in conjunction with flameless
AAS techniques, and optimization of temperature programs for controlling the drying, charring, and atomization processes in
sample analyses, led to improved analytical
detection of diluted urine samples without
the need for sample digestion or ashing.
Roels et al. (1978) successfully used a simple
sample preparation, dilution of 1.0 ml
aliquots of urine with 0.1 N HNO3, to achieve
accurate low-level determinations of CDU.
In the method described by Pruszkowska
et al. (1983), which has become the preferred
method for CDU analysis, urine samples were
diluted at a ratio of 1:5 with water;
diammonium hydrogenphosphate in dilute
§ 1910.1027
HNO3 was used as a matrix modifier. The matrix modifier allows for a higher charring
temperature without loss of cadmium
through
volatilization
during
preatomization. This procedure also employs
a stabilized temperature platform in a
graphite furnace, while nonspecific background absorbtion is corrected using the
Zeeman technique. This method allows for
an absolute detection limit of approximately
0.04 µg Cd/l urine.
5.2.4
Sample collection procedures for CDU may
contribute to variability observed among
CDU measurements. Sources of variation attendant to sampling include time-of-day, the
interval since ingestion of liquids, and the
introduction of external contamination during the collection process. Therefore, to minimize contributions from these variables,
strict adherence to a sample-collection protocol is recommended. This protocol should
include provisions for normalizing the conditions under which urine is collected. Every
effort also should be made to collect samples
during the same time of day.
Collection of urine samples from an industrial work force for biological monitoring
purposes usually is performed using ‘‘spot’’
(i.e., single-void) urine with the pH of the
sample determined immediately. Logistic
and sample-integrity problems arise when efforts are made to collect urine over long periods (e.g., 24 hrs). Unless single-void urines
are used, there are numerous opportunities
for measurement error because of poor control over sample collection, storage and environmental contamination.
To minimize the interval during which
sample urine resides in the bladder, the following adaption to the ‘‘spot’’ collection procedure is recommended: The bladder should
first be emptied, and then a large glass of
water should be consumed; the sample may
be collected within an hour after the water is
consumed.
5.2.5
Best Achievable Performance
Performance using a particular method for
CDU determinations is assumed to be equivalent to the performance reported by the research laboratories in which the method was
developed. Pruszkowska et al. (1983) report a
detection limit of 0.04 µg/l CDU, with a CV of
<4% between 0–5 µg/l. The CDC reports a minimum CDU detection limit of 0.07 µg/l using
a modified method based on Pruszkowska et
al. (1983). No CV is stated in this protocol;
the protocol contains only rejection criteria
for internal QC parameters used during accuracy determinations with known standards
(Attachment 8 of exhibit 106 of OSHA docket
H057A). Stoeppler and Brandt (1980) report a
CDU detection limit of 0.2 µ/l for their methodology.
203
§ 1910.1027
5.2.6
General Method Performance
For any particular method, the expected
initial performance from commercial laboratories may be somewhat lower than that reported by the research laboratory in which
the method was developed. With participation in appropriate proficiency programs,
and use of a proper in-house QA/QC program
incorporating provisions for regular corrective actions, the performance of commercial
laboratories may be expected to improve and
approach that reported by a research laboratories. The results reported for existing proficiency programs serve to specify the initial
level of performance that likely can be expected from commercial laboratories offering analysis using a particular method.
Weber (1988) reports on the results of the
CTQ proficiency program, which includes
CDU results for laboratories participating in
the program. Results indicate that after receiving 60 samples (i.e., after participating in
the program for approximately 3 years), approximately 80% of the participating laboratories report CDU results ranging between ±2
µg/l or 15% of the consensus mean, whichever
is greater. On any single sample of the last
15 samples, the proportion of laboratories
falling within the specified range is between
75 and 95%, except for a single test for which
only 60% of the laboratories reported acceptable results. For each of the last 15 samples,
approximately 60% of the laboratories reported results within ±1 µg or 15% of the
mean, whichever is greater. The range of
concentrations included in this set of samples was not reported.
Another report from the CTQ (1991) summarizes preliminary CDU results from their
1991 interlaboratory program. According to
the report, for 3 CDU samples with values of
9.0, 16.8, 31.5 µg/l, acceptable results (target
of ±2 µg/l or 15 % of the consensus mean,
whichever is greater) were achieved by only
44–52% of the 34 laboratories participating in
the CDU program. The overall CVs for these
3 CDU samples among the 34 participating
laboratories were 31%, 25%, and 49%, respectively. The reason for this poor performance
has not been determined.
A more recent report from the CTQ (Weber,
private communication) indicates that 36%
of the laboratories in the program have been
able to achieve the target of ±1 µg/l or 15%
for more than 75% of the samples analyzed
over the last 5 years, while 45% of participating laboratories achieved a target of ±2
µg/l or 15% for more than 75% of the samples
analyzed over the same period.
Note that results reported in the interlaboratory programs are in terms of µg Cd/l of
urine, unadjusted for creatinine. The performance indicated, therefore, is a measure
of the performance of the cadmium portion
of the analyses, and does not include variation that may be introduced during the
analysis of CRTU.
5.2.7
Observed CDU Concentrations
Prior to the onset of renal dysfunction,
CDU concentrations provide a general indication of the exposure history (i.e., body burden) (see Section 4.3). Once renal dysfunction
occurs, CDU levels appear to increase and
are no longer indicative solely of cadmium
body burden (Friberg and Elinder 1988).
5.2.7.1 Range of CDU concentrations observed
among unexposed samples
Surveys of CDU concentrations in the general population were first reported from cooperative studies among industrial countries
(i.e., Japan, U.S. and Sweden) conducted in
the mid-1970s. In summarizing these data,
Kjellstrom (1979) reported that CDU concentrations among Dallas, Texas men (age
range: <9–59 years; smokers and nonsmokers)
varied from 0.11–1.12 µg/l (uncorrected for
creatinine or specific gravity). These CDU
concentrations are intermediate between
population values found in Sweden (range:
0.11–0.80 µg/l) and Japan (range: 0.14–2.32 µg/l).
Kowal and Zirkes (1983) reported CDU concentrations for almost 1,000 samples collected during 1978–79 from the general U.S.
adult population (i.e., nine states; both genders; ages 20–74 years). They report that CDU
concentrations are lognormally distributed;
low levels predominated, but a small proportion of the population exhibited high levels.
These investigators transformed the CDU
concentrations values, and reported the
same data 3 different ways: µg/l urine
(unadjusted), µg/l (specific gravity adjusted
to 1.020), and µg/g CRTU. These data are summarized in Tables 6 and 7.
Based on further statistical examination of
these data, including the lifestyle characteristics of this group, Kowal (1988) suggested
increased cadmium absorption (i.e., body
burden) was correlated with low dietary intakes of calcium and iron, as well as cigarette smoking.
CDU levels presented in Table 6 are adjusted for age and gender. Results suggest
that CDU levels may be slightly different
among men and women (i.e., higher among
men when values are unadjusted, but lower
among men when the values are adjusted, for
specific gravity or CRTU). Mean differences
among men and women are small compared
to the standard deviations, and therefore
may not be significant. Levels of CDU also
appear to increase with age. The data in
Table 6 suggest as well that reporting CDU
levels adjusted for specific gravity or as a
function of CRTU results in reduced variability.
204
§ 1910.1027
TABLE 6—URINE CADMIUM CONCENTRATIONS IN THE U.S. ADULT POPULATION: NORMAL AND
CONCENTRATION-ADJUSTED VALUES BY AGE AND SEX 1
Geometric means (and geometric standard deviations)
Unadjusted
(µg/l)
Sex:
Male (n=484) ................................................................
Female (n=498) ............................................................
Age:
20–29 (n=222) ..............................................................
30–39 (n=141) ..............................................................
40–49 (n=142) ..............................................................
50–59 (n=117) ..............................................................
60–69 (n=272) ..............................................................
1 From
SG-adjusted 2
µg/l at 1.020)
Creatine-adjusted (µg/g)
0.55 (2.9)
0.49 (3.0)
0.73 (2.6)
0.86 (2.7)
0.55 (2.7)
0.78 (2.7)
0.32
0.46
0.50
0.61
0.76
0.43
0.70
0.81
0.99
1.16
0.32
0.54
0.70
0.90
1.03
(3.0)
(3.2)
(3.0)
(2.9)
(2.6)
(2.7)
(2.8)
(2.6)
(2.4)
(2.3)
(2.7)
(2.7)
(2.7)
(2.3)
(2.3)
Kowal and Zirkes 1983.
is adjusted for specific gravity.
2 SC-adjusted
TABLE 7—URINE CADMIUM CONCENTRATIONS IN THE U.S. ADULT POPULATION: CUMULATIVE
FREQUENCY DISTRIBUTION OF URINARY CADMIUM (N=982) 1
Unadjusted
(µg/l) percent
Range of concentrations
<0.5 ......................................................................................
0.6–1.0 ...............................................................................
1.1–1.5 ...............................................................................
1.6–2.0 ...............................................................................
2.1–3.0 ...............................................................................
3.1–4.0 ...............................................................................
4.1–5.0 ...............................................................................
5.1–10.0 .............................................................................
10.0–20.0 ...........................................................................
1 Source:
28.0
56.4
74.9
84.7
94.4
97.4
98.2
99.4
99.6
Creatine-adjusted (µg/g)
percent
35.8
65.6
81.4
88.9
95.8
97.2
97.9
99.3
99.6
Kowal and Zirkes (1983).
The data in the Table 6 indicate the geometric mean of CDU levels observed among
the general population is 0.52 µ/g Cd/l urine
(unadjusted), with a geometric standard deviation of 3.0. Normalized for creatinine, the
geometric mean for the population is 0.66 µ/
g CRTU, with a geometric standard deviation of 2.7. Table 7 provides the distributions of CDU concentrations for the general
population studied by Kowal and Zirkes. The
data in this table indicate that 95% of the
CDU levels observed among those not occupationally exposed to cadmium are below 3 µ/
g CRTU.
5.2.7.2
43.9
71.7
84.4
91.3
97.3
98.8
99.4
99.6
99.8
SG-adjusted
(µg/l at 1.020)
percent
Range of CDU concentrations observed
among exposed workers
among cadmium-exposed workers. In this
table, arithmetic and/or geometric means
and standard deviations are provided if reported in these studies. The absolute range
for the data in each study, or the 95% confidence interval around the mean of each
study, also are provided when reported. The
lower and upper 95th percentile of the distribution are presented for each study in
which a mean and corresponding standard
deviation were reported. Table 8 also provides estimates of the years of exposure, and
the levels of exposure, to cadmium in the
work place if reported in these studies. Concentrations reported in this table are in µ/g
CRTU, unless otherwise stated.
Table 8 is a summary of results from available studies of CDU concentrations observed
205
Ni-Cd battery plant and
Cd production plant.
(Workers without kidney lesions).
(Workers with kidney
lesions).
Ni-Cd battery plant ..........
(Smokers) ....................
(Nonsmokers) ..............
Cadmium salts production
facility.
Retrospective study of
workers with renal
problems.
(Before removal) ..........
(After removal) .............
Cadmium production
plant.
(Workers without renal
dysfunction).
(Workers with renal
dysfunction).
Cd-Cu alloy plant ............
Cadmium recovery operation.
Pigment manufacturing
plant.
Pigment manufacturing
plant.
1 .............
206
......................
25
10–34
18
26
29
c
b
a
(12.1)
(12.8)
Up to 39
(19)
1–34
33
75
45
(27.2)
(4.2) g
......................
15–41
..............
..............
..............
19
......................
(5)
(9)
(15.4)
......................
96
..............
7
8
148
3–40
Employment
in years
(mean)
..............
Number
in Study
(n)
Concentrations reported in µg/g Cr.
S.D.—Standard Deviation.
C.I.—Confidence Interval.
d GSD—Geometric Standard Deviation.
e Based on an assumed lognormal distribution.
f Based on an assumed normal distribution.
g Years following removal.
h Equivalent to 50 for 20–22 yrs
9 .............
8 .............
6 .............
7 .............
5 .............
4 .............
3 .............
2 .............
Work environment (worker population monitored)
Study
number
....................
....................
≤3.0
6.9±9.4
9.3±6.9
22.8±12.7
9.4±6.9
39.4±28.1
16.4±9.0
....................
....................
....................
5.5
3.6
15.8
48.2±42.6
16.3±16.7
....................
Arithmetic
mean (±
S.D.) b
0.18–3.0
Note h
87
..........................
..........................
..........................
..........................
..........................
..........................
..........................
10.1
7.0
..........................
..........................
..........................
≤ 90
Mean Concentration of
cadmium in air
(µg/m 3)
..................
0.2–9.5
..................
..................
8–55
2-27
10.8–117
80–42.3
..................
..................
..................
1.0–14.7
0.5–9.3
2–150
..................
..................
..................
Absolute
range or
(95% C.I.) c
1.25±2.45
1.1
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
..................
Geometric
mean
(GSD) d
0.3
....................
(0)
(0)
(1)
(0)
(0)
(1.0)
....................
....................
....................
....................
....................
....................
(0)
(0)
....................
Lower 95th
percentile of
range e
( )f
6
....................
(23)
(21)
(45)
(21)
(88)
(32)
....................
....................
....................
....................
....................
....................
(120)
(44)
....................
Upper 95th
percentile of
range e
( )f
Concentration of cadmium in Urine a
Reference
Kawada et al. 1990.
Mueller et al. 1989.
Mason et al. 1988.
Thun et al. 1989.
Ellis et al. 1983.
Roels et al. 1982.
Butchet et al. 1980.
Adamsson et al. (1979).
Lauwerys et al. 1976.
TABLE 8—URINE CADMIUM CONCENTRATIONS IN WORKERS EXPOSED TO CADMIUM IN THE WORKPLACE
§ 1910.1027
Data in Table 8 from Lauwerys et al. (1976)
and Ellis et al. (1983) indicate that CDU concentrations are higher among those exhibiting kidney lesions or dysfunction than
among those lacking these symptoms. Data
from the study by Roels et al. (1982) indicate
that CDU levels decrease among workers removed from occupational exposure to cadmium in comparison to workers experiencing
ongoing exposure. In both cases, however,
the distinction between the 2 groups is not
as clear as with CDB; there is more overlap
in CDU levels observed among each of the
paired populations than is true for corresponding CDB levels. As with CDB levels,
the data in Table 8 suggest increased CDU
concentrations among workers who experienced increased overall exposure.
Although a few occupationally-exposed
workers in the studies presented in Table 8
exhibit CDU levels below 3 µg/g CRTU, most
of those workers exposed to cadmium levels
in excess of the PEL defined in the final cadmium rule exhibit CDU levels above 3 µg/g
CRTU; this level represents the upper 95th
percentile of the CDU distribution observed
among those who are not occupationally exposed to cadmium (Table 7).
The mean CDU levels reported in Table 8
among occupationally-exposed groups studied (except 2) exceed 3 µg/g CRTU. Correspondingly, the level of exposure reported
in these studies (with 1 exception) are significantly higher than what workers will experience under the final cadmium rule. The 2
exceptions are from the studies by Mueller et
al. (1989) and Kawada et al. (1990); these studies indicate that workers exposed to cadmium during pigment manufacture do not
exhibit CDU levels as high as those levels observed among workers exposed to cadmium
in other occupations. Exposure levels, however, were lower in the pigment manufacturing plants studied. Significantly, workers
removed from occupational cadmium exposure for an average of 4 years still exhibited
CDU levels in excess of 3 µg/g CRTU (Roels et
al. 1982). In the single-exception study with a
reported level of cadmium exposure lower
than levels proposed in the final rule (i.e.,
the study of a pigment manufacturing plant
by Kawada et al. 1990), most of the workers
exhibited CDU levels less than 3 µg/g CRTU
(i.e., the mean value was only 1.3 µg/g
CRTU). CDU levels among workers with such
limited cadmium exposure are expected to be
significantly lower than levels of other studies reported in Table 8.
Based on the above data, a CDU level of 3
µg/g CRTU appear to represent a threshold
above which significant work place exposure
to cadmium occurs over the work span of
those being monitored. Note that this
threshold is not as distinct as the corresponding threshold described for CDB. In
general, the variability associated with CDU
measurements among exposed workers ap-
§ 1910.1027
pears to be higher than the variability associated with CDB measurements among similar workers.
5.2.8 Conclusions and Recommendations for
CDU
The above evaluation supports the following recommendations for a CDU proficiency program. These recommendations
address only sampling and analysis procedures for CDU determinations specifically,
which are to be reported as an unadjusted µg
Cd/l urine. Normalizing this result to creatinine requires a second analysis for CRTU so
that the ratio of the 2 measurements can be
obtained. Creatinine analysis is addressed in
Section 5.4. Formal procedures for combining the 2 measurements to derive a value
and a confidence limit for CDU in µg/g CRTU
are provided in Section 3.3.3.
5.2.8.1 Recommended method
The method of Pruszkowska et al. (1983)
should be adopted for CDU analysis. This
method is recommended because it is simple,
straightforward and reliable (i.e., small variations in experimental conditions do not affect the analytical results).
A synopsis of the methods used by laboratories to determine CDU under the interlaboratory program administered by the CTQ
(1991) indicates that more than 78% (24 of 31)
of the participating laboratories use a dilution method to prepare urine samples for
CDU analysis. Laboratories may adopt alternate methods, but it is the responsibility of
the laboratory to demonstrate that the alternate methods provide results of comparable quality to the Pruszkowska method.
5.2.8.2 Data quality objectives
The following data quality objectives
should facilitate interpretation of analytical
results, and are achievable based on the
above evaluation.
Limit of Detection. A level of 0.5 µg/l (i.e.,
corresponding to a detection limit of 0.5 µg/
g CRTU, assuming 1 g CRT/l urine) should be
achievable. Pruszkowska et al. (1983)
achieved a limit of detection of 0.04 µg/l for
CDU based on the slope of the curve for their
working standards (0.35 pg Cd/0.0044, A
signal=1% absorbance using GF-AAS).
The CDC reports a minimum detection
limit for CDU of 0.07 µg/l using a modified
Pruszkowska method. This limit of detection
was defined as 3 times the standard deviation
calculated from 10 repeated measurements of
a ‘‘low level’’ CDU test sample (Attachment
8 of exhibit 106 of OSHA docket H057A).
Stoeppler and Brandt (1980) report a limit
of detection for CDU of 0.2 µg/l using an
aqueous dilution (1:2) of the urine samples.
Accuracy. A recent report from the CTQ
(Weber, private communication) indicates
that 36% of the laboratories in the program
207
§ 1910.1027
achieve the target of ±1 µg/l or 15% for more
than 75% of the samples analyzed over the
last 5 years, while 45% of participating laboratories achieve a target of ±2 µg/l or 15%
for more than 75% of the samples analyzed
over the same period. With time and a strong
incentive for improvement, it is expected
that the proportion of laboratories successfully achieving the stricter level of accuracy
should increase. It should be noted, however,
these indices of performance do not include
variations resulting from the ancillary
measurement of CRTU (which is recommended for the proper recording of results). The low cadmium levels expected to
be measured indicate that the analysis of
creatinine will contribute relatively little to
the overall variability observed among creatinine-normalized CDU levels (see Section
5.4). The initial target value for reporting
CDU under this program, therefore, is set at
±1 µg/g CRTU or 15% (whichever is greater).
Precision. For internal QC samples (which
are recommended as part of an internal QA/
QC program, Section 3.3.1), laboratories
should attain an overall precision of 25%.
For CDB samples with concentrations less
than 2 µg/l, a target precision of 40% is acceptable, while precisions of 20% should be
achievable for CDU concentrations greater
than 2 µg/l. Although these values are more
stringent than those observed in the CTQ
interlaboratory program reported by Webber
(1988), they are well within limits expected
to be achievable for the method as reported
by Stoeppler and Brandt (1980).
5.2.8.3
Quality assurance/quality control
Commercial laboratories providing CDU
determinations should adopt an internal QA/
QC program that incorporates the following
components: Strict adherence to the selected
method, including calibration requirements;
regular incorporation of QC samples during
actual runs; a protocol for corrective actions, and documentation of such actions;
and, participation in an interlaboratory proficiency program. Note that the nonmandatory program presented in Attachment 1 as
an example of an acceptable QA/QC program,
is based on using the Pruszkowska method
for CDU analysis. Should an alternate method be adopted by a laboratory, the laboratory should develop a QA/QC program equivalent to the nonmandatory program, and
which satisfies the provisions of Section
3.3.1.
5.3
Monitoring β-2–Microglobulin in Urine
(B2MU)
As indicated in Section 4.3, B2MU appears
to be the best of several small proteins that
may be monitored as early indicators of cadmium-induced renal damage. Several analytic techniques are available for measuring
B2M.
5.3.1
Units of B2MU Measurement
Procedures adopted for reporting B2MU
levels are not uniform. In these guidelines,
OSHA recommends that B2MU levels be reported as µg/g CRTU, similar to reporting
CDU concentrations. Reporting B2MU normalized to the concentration of CRTU requires an additional analytical process beyond the analysis of B2M: Independent analysis for creatinine so that results may be reported as a ratio of the B2M and creatinine
concentrations found in the urine sample.
Consequently, the overall quality of the
analysis depends on the combined performance on these 2 analyses. The analysis used
for B2MU determinations is described in
terms of µg B2M/l urine, with analysis of creatinine addressed separately. Techniques
used to measure creatinine are provided in
Section 5.4. Note that Section 3.3.3 provides
techniques for deriving the value of B2M as
function of CRTU, and the confidence limits
for independent measurements of B2M and
CRTU.
5.3.2
Monitor B2MU
One of the earliest tests used to measure
B2MU was the radial immunodiffusion technique. This technique is a simple and specific
method for identification and quantitation
of a number of proteins found in human
serum and other body fluids when the protein is not readily differentiated by standard
electrophoretic procedures. A quantitative
relationship exists between the concentration of a protein deposited in a well that is
cut into a thin agarose layer containing the
corresponding monospecific antiserum, and
the distance that the resultant complex diffuses. The wells are filled with an unknown
serum and the standard (or control), and incubated in a moist environment at room
temperature. After the optimal point of diffusion has been reached, the diameters of the
resulting precipition rings are measured. The
diameter of a ring is related to the concentration of the constituent substance. For
B2MU determinations required in the medical monitoring program, this method requires a process that may be insufficient to
concentrate the protein to levels that are required for detection.
Radioimmunoassay (RIA) techniques are
used widely in immunologic assays to measure the concentration of antigen or antibody
in body-fluid samples. RIA procedures are
based on competitive-binding techniques. If
antigen concentration is being measured, the
principle underlying the procedure is that
radioactive-labeled antigen competes with
the sample’s unlabeled antigen for binding
sites on a known amount of immobile antibody. When these 3 components are present
in the system, an equilibrium exists. This
equilibrium is followed by a separation of
208
the free and bound forms of the antigen. Either free or bound radioactive-labeled antigen can be assessed to determine the amount
of antigen in the sample. The analysis is performed by measuring the level of radiation
emitted either by the bound complex following removal of the solution containing
the free antigen, or by the isolated solution
containing the residual-free antigen. The
main advantage of the RIA method is the extreme sensitivity of detection for emitted radiation and the corresponding ability to detect trace amounts of antigen. Additionally,
large numbers of tests can be performed rapidly.
The enzyme-linked immunosorbent assay
(ELISA) techniques are similar to RIA techniques except that nonradioactive labels are
employed. This technique is safe, specific
and rapid, and is nearly as sensitive as RIA
techniques. An enzyme-labeled antigen is
used in the immunologic assay; the labeled
antigen detects the presence and quantity of
unlabeled antigen in the sample. In a representative ELISA test, a plastic plate is
coated with antibody (e.g., antibody to B2M).
The antibody reacts with antigen (B2M) in
the urine and forms an antigen-antibody
complex on the plate. A second anti-B2M
antibody (i.e., labeled with an enzyme) is
added to the mixture and forms an antibodyantigen-antibody complex. Enzyme activity
is measured spectrophotometrically after
the addition of a specific chromogenic substrate which is activated by the bound enzyme. The results of a typical test are calculated
by
comparing
the
spectrophotometric reading of a serum sample to that of a control or reference serum.
In general, these procedures are faster and
require less laboratory work than other
methods.
In a fluorescent ELISA technique (such as
the one employed in the Pharmacia Delphia
test for B2M), the labeled enzyme is bound to
a strong fluorescent dye. In the Pharmacia
Delphia test, an antigen bound to a fluorescent dye competes with unlabeled antigen in
the sample for a predetermined amount of
specific, immobile antibody. Once equilibrium is reached, the immobile phase is removed from the labeled antigen in the sample solution and washed; an enhancement solution then is added that liberates the fluorescent dye from the bound antigen-antibody
complex. The enhancement solution also
contains a chelate that complexes with the
fluorescent dye in solution; this complex increases the fluorescent properties of the dye
so that it is easier to detect.
To determine the quantity of B2M in a
sample using the Pharmacia Delphia test,
the intensity of the fluorescence of the enhancement solution is measured. This intensity is proportional to the concentration of
§ 1910.1027
labeled antigen that bound to the immobile
antibody phase during the initial competition with unlabeled antigen from the sample.
Consequently, the intensity of the fluorescence is an inverse function of the concentration of antigen (B2M) in the original
sample. The relationship between the fluorescence level and the B2M concentration in
the sample is determined using a series of
graded standards, and extrapolating these
standards to find the concentration of the
unknown sample.
5.3.3 Methods Developed for B2MU
Determinations
B2MU
usually
is
measured
by
radioimmunoassay (RIA) or enzyme-linked
immunosorbent assay (ELISA); however,
other methods (including gel electrophoresis,
radial immunodiffusion, and nephelometric
assays) also have been described (Schardun
and van Epps 1987). RIA and ELISA methods
are preferred because they are sensitive at
concentrations as low as micrograms per
liter, require no concentration processes, are
highly reliable and use only a small sample
volume.
Based on a survey of the literature, the
ELISA technique is recommended for monitoring B2MU. While RIAs provide greater
sensitivity (typically about 1 µg/l, Evrin et
al. 1971), they depend on the use of
radioisotopes; use of radioisotopes requires
adherence to rules and regulations established by the Atomic Energy Commission,
and necessitates an expensive radioactivity
counter for testing. Radioisotopes also have
a relatively short half-life, which corresponds to a reduced shelf life, thereby increasing the cost and complexity of testing.
In contrast, ELISA testing can be performed
on routine laboratory spectrophotometers,
do not necessitate adherence to additional
rules and regulations governing the handling
of radioactive substances, and the test kits
have long shelf lives. Further, the range of
sensitivity commonly achieved by the recommended ELISA test (i.e., the Pharmacia
Delphia test) is approximately 100 µg/l
(Pharmacia 1990), which is sufficient for
monitoring B2MU levels resulting from cadmium exposure. Based on the studies listed
in Table 9 (Section 5.3.7), the average range
of B2M concentrations among the general,
nonexposed population falls between 60 and
300 µg/g CRTU. The upper 95th percentile of
distributions, derived from studies in Table 9
which reported standard deviations, range
between 180 and 1,140 µg/g CRTU. Also, the
Pharmacia Delphia test currently is the
most widely used test for assessing B2MU.
209
§ 1910.1027
5.3.4
As with CDB or CDU, sample collection
procedures are addressed primarily to identify ways to minimize the degree of variability introduced by sample collection during medical monitoring. It is unclear the extent to which sample collection contributes
to B2MU variability. Sources of variation include time-of-day effects, the interval since
consuming liquids and the quantity of liquids consumed, and the introduction of external contamination during the collection
process. A special problem unique to B2M
sampling is the sensitivity of this protein to
degradation under acid conditions commonly
found in the bladder. To minimize this problem, strict adherence to a sampling protocol
is recommended. The protocol should include
provisions for normalizing the conditions
under which the urine is collected. Clearly,
it is important to minimize the interval
urine spends in the bladder. It also is recommended that every effort be made to collect samples during the same time of day.
Collection of urine samples for biological
monitoring usually is performed using
‘‘spot’’ (i.e., single-void) urine. Logistics and
sample integrity become problems when efforts are made to collect urine over extended
periods (e.g., 24 hrs). Unless single-void
urines are used, numerous opportunities
exist for measurement error because of poor
control over sample collection, storage and
environmental contamination.
To minimize the interval that sample
urine resides in the bladder, the following
adaption to the ‘‘spot’’ collection procedure
is recommended: The bladder should be
emptied and then a large glass of water
should be consumed; the sample then should
be collected within an hour after the water is
consumed.
5.3.5
Best Achievable Performance
The best achievable performance is assumed to be equivalent to the performance
reported by the manufacturers of the
Pharmacia Delphia test kits (Pharmacia
1990). According to the insert that comes
with these kits, QC results should be within
±2 SDs of the mean for each control sample
tested; a CV of less than or equal to 5.2%
should be maintained. The total CV reported
for test kits is less than or equal to 7.2%.
5.3.6 General Method Performance
Unlike analyses for CDB and CDU, the
Pharmacia Delphia test is standardized in a
commercial kit that controls for many
sources of variation. In the absence of data
to the contrary, it is assumed that the
achievable performance reported by the
manufacturer of this test kit will serve as an
achievable performance objective. The CTQ
proficiency testing program for B2MU analysis is expected to use the performance parameters defined by the test kit manufacturer as the basis of the B2MU proficiency
testing program.
Note that results reported for the test kit
are expressed in terms of µg B2M/l of urine,
and have not been adjusted for creatinine.
The indicated performance, therefore, is a
measure of the performance of the B2M portion of the analyses only, and does not include variation that may have been introduced during the analysis of creatinine.
5.3.7 Observed B2MU Concentrations
As indicated in Section 4.3, the concentration of B2MU may serve as an early indicator
of the onset of kidney damage associated
with cadmium exposure.
5.3.7.1 Range of B2MU Concentrations
Among Unexposed Samples
Most of the studies listed in Table 9 report
B2MU levels for those who were not occupationally exposed to cadmium. Studies noted
in the second column of this table (which
contain the footnote ‘‘d’’) reported B2MU
concentrations
among
cadmium-exposed
workers who, nonetheless, showed no signs of
proteinuria. These latter studies are included in this table because, as indicated in
Section 4.3, monitoring B2MU is intended to
provide advanced warning of the onset of
kidney dysfunction associated with cadmium
exposure, rather than to distinguish relative
exposure. This table, therefore, indicates the
range of B2MU levels observed among those
who had no symptoms of renal dysfunction
(including cadmium-exposed workers with
none of these symptoms).
TABLE 9—B-2–MICROGLOBULIN CONCENTRATIONS OBSERVED IN URINE AMONG THOSE NOT
OCCUPATIONALLY EXPOSED TO CADMIUM
No. in
study
Geometric
mean
Geometric
standard
deviation
Lower
95th percentile of
distributiona
Upper
95th percentile of
distributiona
1 ............
133 m b
4.03 .......
12 ..........
2 ............
161 f b ..
115 µg/
g c.
146 µg/
g c.
3.11 .......
23 ..........
1,140 µg/
g c.
940 µg/
g c.
Study
No.
210
Reference
Ishizaki et al. 1989.
Ishizaki et al. 1989.
§ 1910.1027
TABLE 9—B-2–MICROGLOBULIN CONCENTRATIONS OBSERVED IN URINE AMONG THOSE NOT
OCCUPATIONALLY EXPOSED TO CADMIUM—Continued
No. in
study
Geometric
mean
Geometric
standard
deviation
Lower
95th percentile of
distributiona
Upper
95th percentile of
distributiona
............
............
............
............
............
10 .........
203 .......
9 ...........
47 d .......
1,000 e ..
...............
...............
...............
1.9 .........
3.1 m & f
87 .........
10 .........
...............
...............
...............
...............
...............
30 µg/1 ..
< 10 µg/
gr Cr h.
7 h ..........
...............
...............
...............
...............
250 µg/L
320 µg/gr
Cr h.
200 h ......
...............
Ellis et al. 1983.
Stewart and Hughes 1981.
Chia et al. 1989.
Kjellstrom et al. 1977.
Kowal 1983.
8 ............
9 ............
10
11
12
13
..........
..........
..........
..........
59 .........
8 ...........
34 .........
41 m ....
84 µg/g
76 µg/l ..
103 µg/g
86 µg/L
68.1 µg/
gr Cr f.
71 µg/g i
0.073
mg/
24h.
156 µg/g
118 µg/g
79 µg/g
..............
1.1 j ........
...............
...............
...............
130 ........
...............
...............
...............
Mason et al. 1988.
Iwao et al. 1980.
Wibowo et al. 1982.
Falck et al. 1983.
14
15
16
17
18
19
..........
..........
..........
..........
..........
..........
35 n
31 d
36 d
18 n
32 p
18 d
67 .........
63 .........
77 i ........
130 .......
122 .......
295 .......
...............
...............
...............
...............
...............
1.4 .........
...............
...............
...............
...............
...............
170 ........
180 ........
...............
...............
400 µg/gr
Cr k.
...............
...............
...............
...............
...............
510 ........
Study
No.
3
4
5
6
7
.......
.......
.......
.......
.......
.......
Reference
Buchet et al. 1980.
Evrin et al. 1971.
Roels et al. 1991.
Roels et al. 1991.
Miksche et al. 1981.
Kawada et al. 1989.
Kawada et al. 1989.
Thun et al. 1989.
a—Based on an assumed lognormal distribution.
b—m = males, f = females.
c—Aged general population from non-polluted area; 47.9% population aged 50–69; 52.1% ≥ 70 years of
age; values reported in study.
d—Exposed workers without proteinuria.
e—492 females, 484 male.
f—Creatinine adjusted; males = 68.1 µg/g Cr, females = 64.3 µg/g Cr.
h—Reported in the study.
i—Arithmetic mean.
j—Geometric standard error.
k—Upper 95% tolerance limits: for Falck this is based on the 24 hour urine sample.
n—Controls.
p—Exposed synthetic resin and pigment workers without proteinuria; Cadmium in urine levels up to 10 µg/g
Cr.
To the extent possible, the studies listed in
Table 9 provide geometric means and geometric standard deviations for measurements among the groups defined in each
study. For studies reporting a geometric
standard deviation along with a mean, the
lower and upper 95th percentile for these distributions were derived and reported in the
table.
The data provided from 15 of the 19 studies
listed in Table 9 indicate that the geometric
mean concentration of B2M observed among
those who were not occupationally exposed
to cadmium is 70–170 µg/g CRTU. Data from
the 4 remaining studies indicate that exposed workers who exhibit no signs of proteinuria show mean B2MU levels of 60–300 µg/
g CRTU. B2MU values in the study by Thun
et al. (1989), however, appear high in comparison to the other 3 studies. If this study is
removed, B2MU levels for those who are not
occupationally exposed to cadmium are similar to B2MU levels found among cadmiumexposed workers who exhibit no signs of kidney dysfunction. Although the mean is high
in the study by Thun et al., the range of
measurements reported in this study is within the ranges reported for the other studies.
Determining a reasonable upper limit from
the range of B2M concentrations observed
among those who do not exhibit signs of proteinuria is problematic. Elevated B2MU levels are among the signs used to define the
onset of kidney dysfunction. Without access
to the raw data from the studies listed in
Table 9, it is necessary to rely on reported
standard deviations to estimate an upper
limit for normal B2MU concentrations (i.e.,
the upper 95th percentile for the distributions measured). For the 8 studies reporting
a geometric standard deviation, the upper
95th percentiles for the distributions are 180–
211
§ 1910.1027
1140 µg/g CRTU. These values are in general
agreement with the upper 95th percentile for
the distribution (i.e., 631 µg/g CRTU) reported by Buchet et al. (1980). These upper
limits also appear to be in general agreement with B2MU values (i.e., 100–690 µg/g
CRTU) reported as the normal upper limit by
Iwao et al. (1980), Kawada et al. (1989),
Wibowo et al. (1982), and Schardun and van
Epps (1987). These values must be compared
to levels reported among those exhibiting
kidney dysfunction to define a threshold
level for kidney dysfunction related to cadmium exposure.
5.3.7.2
Range of B2MU Concentrations
Among Exposed Workers
Table 10 presents results from studies reporting B2MU determinations among those
occupationally exposed to cadmium in the
work place; in some of these studies, kidney
dysfunction was observed among exposed
workers, while other studies did not make an
effort to distinguish among exposed workers
based on kidney dysfunction. As with Table
9, this table provides geometric means and
geometric standard deviations for the groups
defined in each study if available. For studies reporting a geometric standard deviation
along with a mean, the lower and upper 95th
percentiles for the distributions are derived
and reported in the table.
TABLE 10—B-2-MICROGLOBULIN CONCENTRATIONS OBSERVED IN URINE AMONG OCCUPATIONALLYEXPOSED WORKERS
Concentration of B-2-Microglobulin in urine
Study No.
1 ...................................
2 ...................................
3
4
5
6
7
8
9
10
11
12
13
14
15
16
...................................
...................................
...................................
...................................
...................................
...................................
...................................
...................................
...................................
...................................
...................................
...................................
...................................
...................................
N
1,42
4
1,75
4
33
65
c44
148
37
c 45
c 10
c 11
c 12
g8
c 23
10
34
c 15
Geometric
mean
(µg/g) a
Geom
std dev
160
6.19
260
6.50
210
210
5,700
e 180
160
3,300
6,100
3,900
300
7,400
h 1,800
690
71
4,700
..............
..............
6.49
..............
3.90
8.7
5.99
2.96
..............
..............
..............
..............
..............
6.49
L 95% of
range b
8.1
12
................
................
d 300
f 110
17
d 310
f 650
d 710
................
................
................
................
................
d 590
U 95% of
range b
Reference
3,300
Ishizaki et al., 1989.
5,600
Ishizaki et al., 1989.
................
................
d 98,000
f 280
1,500
d 89,000
f 57,000
d 15,000
................
................
................
................
................
d 93,000
Ellis et al., 1983.
Chia et al., 1989.
Kjellstrom et al., 1977.
Buchet et al., 1980.
Kenzaburo et al., 1979.
Mason et al., 1988.
Falck et al., 1983.
Elinder et al., 1985.
Roels et al., 1991.
Roels et al., 1991.
Roels et al., 1989.
Iwao et al., 1980.
Wibowo et al., 1982.
Thun et al., 1989.
a Unless
otherwise stated.
on an assumed lognormal distribution.
workers diagnosed as having renal dysfunction; for Elinder this means β 2 levels greater than 300
micrograms per gram creatinine (µg/gr Cr); for Roels, 1991, range = 31 ¥ 35, 170 µgβ2/gr Cr and geometric
mean = 63 among healthy workers; for Mason β2 > 300 µg/gr Cr.
d Based on a detailed review of the data by OSHA.
e Arthmetic mean.
f Reported in the study.
g Retired workers.
h 1,800 µgβ /gr Cr for first survey; second survey = 1,600; third survey = 2,600; fourth survey = 2,600; fifth
2
survey = 2,600.
b Based
c Among
The data provided in Table 10 indicate that
the mean B2MU concentration observed
among workers experiencing occupational
exposure to cadmium (but with undefined
levels of proteinuria) is 160–7400 µg/g CRTU.
One of these studies reports geometric means
lower than this range (i.e., as low as 71 µg/g
CRTU); an explanation for this wide spread
in average concentrations is not available.
Seven of the studies listed in Table 10 report a range of B2MU levels among those diagnosed as having renal dysfunction. As indicated in this table, renal dysfunction (proteinuria) is defined in several of these studies by B2MU levels in excess of 300 µg/g CRTU
212
(see footnote ‘‘c’’ of Table 10); therefore, the
range of B2MU levels observed in these studies is a function of the operational definition
used to identify those with renal dysfunction. Nevertheless, a B2MU level of 300 µg/g
CRTU appears to be a meaningful threshold
for identifying those having early signs of
kidney damage. While levels much higher
than 300 µg/g CRTU have been observed
among those with renal dysfunction, the
vast majority of those not occupationally exposed to cadmium exhibit much lower B2MU
concentrations (see Table 9). Similarly, the
vast majority of workers not exhibiting renal
dysfunction are found to have levels below
300 µg/g CRTU (Table 9).
The 300 µg/g CRTU level for B2MU proposed
in the above paragraph has support among
researchers as the threshold level that distinguishes between cadmium-exposed workers with and without kidney dysfunction.
For example, in the guide for physicians who
must evaluate cadmium-exposed workers
written for the Cadmium Council by Dr.
Lauwerys, levels of B2M greater than 200–300
µg/g CRTU are considered to require additional medical evaluation for kidney dysfunction (exhibit 8–447, OSHA docket H057A).
The most widely used test for measuring
B2M (i.e., the Pharmacia Delphia test) defines B2MU levels above 300 µg/l as abnormal
(exhibit L–140–1, OSHA docket H057A).
Dr. Elinder, chairman of the Department
of Nephrology at the Karolinska Institute,
testified at the hearings on the proposed cadmium rule. According to Dr. Elinder (exhibit
L–140–45, OSHA docket H057A), the normal
concentration of B2MU has been well documented (Evrin and Wibell 1972; Kjellstrom et
al. 1977a; Elinder et al. 1978, 1983; Buchet et
al. 1980; Jawaid et al. 1983; Kowal and Zirkes,
1983). Elinder stated that the upper 95 or 97.5
percentiles for B2MU among those without
tubular dysfunction is below 300 µg/g CRTU
(Kjellstrom et al. 1977a; Buchet et al. 1980;
Kowal and Zirkes, 1983). Elinder defined levels of B2M above 300 µg/g CRTU as ‘‘slight’’
proteinuria.
5.3.8
Conclusions and Recommendations for
B2MU
Based on the above evaluation, the following recommendations are made for a
B2MU proficiency testing program. Note
that the following discussion addresses only
sampling and analysis for B2MU determinations (i.e., to be reported as an unadjusted µg
B2M/l urine). Normalizing this result to creatinine requires a second analysis for CRTU
(see Section 5.4) so that the ratio of the 2
measurements can be obtained.
5.3.8.1
Recommended method
The
Pharmacia
Delphia
method
(Pharmacia 1990) should be adopted as the
standard method for B2MU determinations.
§ 1910.1027
Laboratories may adopt alternate methods,
but it is the responsibility of the laboratory
to demonstrate that alternate methods provide results of comparable quality to the
Pharmacia Delphia method.
5.3.8.2 Data quality objectives
The following data quality objectives
should facilitate interpretation of analytical
results, and should be achievable based on
the above evaluation.
Limit of Detection. A limit of 100 µg/l urine
should be achievable, although the insert to
the test kit (Pharmacia 1990) cites a detection limit of 150 µg/l; private conversations
with representatives of Pharmacia, however,
indicate that the lower limit of 100 µg/l
should be achievable provided an additional
standard of 100 µg/l B2M is run with the other
standards to derive the calibration curve
(Section 3.3.1.1). The lower detection limit is
desirable due to the proximity of this detection limit to B2MU values defined for the
cadmium medical monitoring program.
Accuracy. Because results from an interlaboratory proficiency testing program are not
available currently, it is difficult to define
an achievable level of accuracy. Given the
general performance parameters defined by
the insert to the test kits, however, an accuracy of ±15% of the target value appears
achievable.
Due to the low levels of B2MU to be measured generally, it is anticipated that the
analysis of creatinine will contribute relatively little to the overall variability observed among creatinine-normalized B2MU
levels (see Section 5.4). The initial level of
accuracy for reporting B2MU levels under
this program should be set at ±15%.
Precision. Based on precision data reported
by Pharmacia (1990), a precision value (i.e.,
CV) of 5% should be achievable over the defined range of the analyte. For internal QC
samples (i.e., recommended as part of an internal QA/QC program, Section 3.3.1), laboratories should attain precision near 5% over
the range of concentrations measured.
5.3.8.3 Quality assurance/quality control
Commercial laboratories providing measurement of B2MU should adopt an internal
QA/QC program that incorporates the following components: Strict adherence to the
Pharmacia Delphia method, including calibration requirements; regular use of QC samples during routine runs; a protocol for corrective actions, and documentation of these
actions; and, participation in an interlaboratory proficiency program. Procedures that
may be used to address internal QC requirements are presented in Attachment 1. Due to
differences between analyses for B2MU and
CDB/CDU, specific values presented in Attachment 1 may have to be modified. Other
213
§ 1910.1027
components of the program (including characterization runs), however, can be adapted
to a program for B2MU.
5.4
Monitoring Creatinine in Urine (CRTU)
Because CDU and B2MU should be reported
relative to concentrations of CRTU, these
concentrations should be determined in addition CDU and B2MU determinations.
5.4.1
Units of CRTU Measurement
CDU should be reported as µg Cd/g CRTU,
while B2MU should be reported as µg B2M/g
CRTU. To derive the ratio of cadmium or
B2M to creatinine, CRTU should be reported
in units of g crtn/l of urine. Depending on the
analytical method, it may be necessary to
convert results of creatinine determinations
accordingly.
5.4.2
Monitor CRTU
Of the techniques available for CRTU determinations,
an
absorbance
spectrophotometric technique and a highperformance liquid chromatography (HPLC)
technique are identified as acceptable in this
protocol.
5.4.3
Methods Developed for CRTU
Determinations
5.4.6
Observed CRTU Concentrations
Published data suggest the range of CRTU
concentrations is 1.0–1.6 g in 24-hour urine
samples (Harrison 1987). These values are
equivalent to about 1 g/l urine.
5.4.7 Conclusions and Recommendations for
CRTU
5.4.7.1
CRTU samples should be segregated from
samples collected for CDU or B2MU analysis.
Sample-collection techniques have been described under Section 5.2.4. Samples should
be preserved either to stabilize CDU (with
HNO3) or B2MU (with NaOH). Neither of
these procedures should adversely affect
CRTU analysis (see Attachment 3).
Recommended method
Use either the Jaffe method (Attachment
2) or the OSLTC method (Attachment 3). Alternate methods may be acceptable provided
adequate performance is demonstrated in the
CAP program.
5.4.7.2
CRTU analysise performed in support of either CDU or B2MU determinations should be
performed using either of the following 2
methods:
1. The Du Pont method (i.e., Jaffe method),
in which creatinine in a sample reacts with
picrate under alkaline conditions, and the
resulting red chromophore is monitored (at
510 nm) for a fixed interval to determine the
rate of the reaction; this reaction rate is proportional to the concentration of creatinine
present in the sample (a copy of this method
is provided in Attachment 2 of this protocol);
or,
2. The OSHA SLC Technical Center
(OSLTC) method, in which creatinine in an
aliquot of sample is separated using an
HPLC column equipped with a UV detector;
the resulting peak is quantified using an
electrical integrator (a copy of this method
is provided in Attachment 3 of this protocol).
5.4.4
5.4.5 General Method Performance
Data from the OSLTC indicate that a CV
of 5% should be achievable using the OSLTC
method (Septon, L private communication).
The achievable accuracy of this method has
not been determined.
Results reported in surveys conducted by
the CAP (CAP 1991a, 1991b and 1992) indicate
that a CV of 5% is achievable. The accuracy
achievable for CRTU determinations has not
been reported.
Laboratories performing creatinine analysis under this protocol should be CAP accredited and should be active participants in
the CAP surveys.
Data quality objectives
Limit of Detection. This value has not been
formally defined; however, a value of 0.1 g/l
urine should be readily achievable.
Accuracy. This value has not been defined
formally; accuracy should be sufficient to retain accreditation from the CAP.
Precision. A CV of 5% should be achievable
using the recommended methods.
6.0
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NC, Population Studies Division. NTIS No.
PB–285–200.
Stewart M and Hughes E. (1981). Urinary B–
2-microglobulin in the biological monitoring
of cadmium workers. British Journal of Industrial Medicine, 38, 170–174.
Stoeppler K and Brandt M. (1980). Contributions to automated trace analysis. Part
V. Determination of cadmium in whole blood
and urine by electrothermal atomic absorption spectrophotometry. Fresenius’ Zeitschrift
fur Analytical Chemistry, 300, 372–380.
Takenaka et al. (1983). Carcinogencity of Cd
Chloride Aerosols in White Rates. INCI 70: 367–
373, 1983.
Thun M, Osorio A, Schober S, Hannon W,
Lewis B, and Halperin W. (1989). Nephropathy
in cadmium workers: Assessment of risk
from airborne occupational exposure to cadmium. British Journal of Industrial Medicine,
46, 689–697.
Thun M, Schnorr T, Smith A, Halperin W,
and Lemen R. (1985). Mortality among a cohort of US cadmium production workers—an
update. Journal of the National Cancer Institute, 74, 325–333.
Travis D and Haddock A. (1980). Interpretation of the observed age-dependency of cadmium body burdens in man. Environmental
Research, 22, 46–60.
Tsuchiya K. (1967). Proteinuria of workers
exposed to cadmium fume. Archives of Environmental Health, 14, 875–880.
Tsuchiya K. (1976). Proteinuria of cadmium
workers. Journal of Occupational Medicine, 18,
463–470.
Tsuchiya K, Iwao S, Sugita M, Sakurai H.
(1979). Increased urinary B-2-microglobulin
in cadmium exposure: Dose-effect relationship and biological significance of B-2-microglobulin. Environmental Health Perspectives,
28, 147–153.
USEPA. (1985). Updated Mutagenicity and
Carcinogenicity Assessments of Cd: Addendum to the Health Assessment Document for
Cd (May 1981). Final Report. June 1985.
Vahter M and Friberg L. (1988). Quality
control in integrated human exposure monitoring of lead and cadmium. Fresenius’
Zeitschrift fur Analytical Chemistry, 332, 726–
731.
Weber J. (1988). An interlaboratory comparison programme for several toxic substances in blood and urine. The Science of the
Total Environment, 71, 111–123.
Weber J. (1991a). Accuracy and precision of
trace metal determinations in biological
fluids. In K. Subramanian, G. Iyengar, and K.
217
§ 1910.1027
Okamot (Eds.), Biological Trace Element Research-Multidisciplinary Perspectives, ACS
Symposium Series 445. Washington, DC:
American Chemical Society.
Weber J. (1991b). Personal communication
about interlaboratory program and shipping
biological media samples for cadmium analyses.
Wibowo A, Herber R, van Deyck W, and
Zielhuis R. (1982). Biological assessment of
exposure in factories with second degree
usage of cadmium compounds. International
Archives
of
Occupational
Environmental
Health, 49, 265–273.
Attachment 1: Nonmandatory Protocol for
an Internal Quality Assurance/Quality
Control Program
The following is an example of the type of
internal quality assurance/quality control
program that assures adequate control to
satisfy OSHA requirements under this protocol. However, other approaches may also
be acceptable.
As indicated in Section 3.3.1 of the protocol, the QA/QC program for CDB and CDU
should address, at a minimum, the following:
• calibration;
• establishment of control limits;
• internal QC analyses and maintaining
control; and
• corrective action protocols.
This illustrative program includes both
initial characterization runs to establish the
performance of the method and ongoing
analysis
of
quality
control
samples
intermixed with compliance samples to
maintain control.
Calibration
Before any analytical runs are conducted,
the analytic instrument must be calibrated.
This is to be done at the beginning of each
day on which quality control samples and/or
compliance samples are run. Once calibration is established, quality control samples
or compliance samples may be run. Regardless of the type of samples run, every fifth
sample must be a standard to assure that the
calibration is holding.
Calibration is defined as holding if every
standard is within plus or minus (±) 15% of
its theoretical value. If a standard is more
than plus or minus 15% of its theoretical
value, then the run is out of control due to
calibration error and the entire set of samples must either be reanalyzed after recalibrating or results should be recalculated
based on a statistical curve derived from the
measurement of all standards.
It is essential that the highest standard
run is higher than the highest sample run.
To assure that this is the case, it may be
necessary to run a high standard at the end
of the run, which is selected based on the results obtained over the course of the run.
All standards should be kept fresh, and as
they get old, they should be compared with
new standards and replaced if they exceed
the new standards by ± 15%.
INITIAL CHARACTERIZATION RUNS AND
ESTABLISHING CONTROL
A participating laboratory should establish
four pools of quality control samples for
each of the analytes for which determinations will be made. The concentrations of
quality control samples within each pool are
to be centered around each of the four target
levels for the particular analyte identified in
Section 4.4 of the protocol.
Within each pool, at least 4 quality control
samples need to be established with varying
concentrations ranging between plus or
minus 50% of the target value of that pool.
Thus for the medium-high cadmium in blood
pool, the theoretical values of the quality
control samples may range from 5 to 15 µg/l,
(the target value is 10 µg/l). At least 4 unique
theoretical values must be represented in
this pool.
The range of theoretical values of plus or
minus 50% of the target value of a pool
means that there will be overlap of the pools.
For example, the range of values for the medium-low pool for cadmium in blood is 3.5 to
10.5 µg/l while the range of values for the medium-high pool is 5 to 15 µg/l. Therefore, it is
possible for a quality control sample from
the medium-low pool to have a higher concentration of cadmium than a quality control sample from the medium-high pool.
Quality control samples may be obtained
as commercially available reference materials, internally prepared, or both. Internally
prepared samples should be well characterized and traced or compared to a reference
material for which a consensus value for concentration is available. Levels of analyte in
the quality control samples must be concealed from the analyst prior to the reporting of analytical results. Potential sources of
materials that may be used to construct
quality control samples are listed in Section
3.3.1 of the protocol.
Before any compliance samples are analyzed, control limits must be established.
Control limits should be calculated for every
pool of each analyte for which determinations will be made and control charts should
be kept for each pool of each analyte. A separate set of control charts and control limits
should be established for each analytical instrument in a laboratory that will be used
for analysis of compliance samples.
At the beginning of this QA/QC program,
control limits should be based on the results
of the analysis of 20 quality control samples
from each pool of each analyte. For any
given pool, the 20 quality control samples
should be run on 20 different days. Although
no more than one sample should be run from
218
any single pool on a particular day, a laboratory may run quality control samples from
different pools on the same day. This constitutes a set of initial characterization
runs.
For each quality control sample analyzed,
the value F/T (defined in the glossary) should
be calculated. To calculate the control limits for a pool of an analyte, it is first necessary to calculate the mean, X̄, of the F/T
values for each quality control sample in a
pool and then to calculate its standard deviation σ. Thus, for the control limit for a
pool, X̄ is calculated as:
 F
∑ T
N
and σ is calculated as
1
2
 F
 2
 ∑  − X 
T


N −1






Where N is the number of quality control
samples run for a pool.
The control limit for a particular pool is
then given by the mean plus or minus 2
standard deviations (X ± 3σ).
The control limits may be no greater than
40% of the mean F/T value. If three standard
deviations are greater than 40% of the mean
F/T value, then analysis of compliance samples may not begin.1 Instead, an investigation into the causes of the large standard deviation should begin, and the inadequacies
must be remedied. Then, control limits must
be reestablished which will mean repeating
the running 20 quality control samples from
each pool over 20 days.
§ 1910.1027
Internal Quality Control Analyses and
Maintaining Control
Once control limits have been established
for each pool of an analyte, analysis of compliance samples may begin. During any run
of compliance samples, quality control samples are to be interspersed at a rate of no less
than 5% of the compliance sample workload.
When quality control samples are run, however, they should be run in sets consisting of
one quality control sample from each pool.
Therefore, it may be necessary, at times, to
intersperse quality control samples at a rate
greater than 5%.
There should be at least one set of quality
control samples run with any analysis of
compliance samples. At a minimum, for example, 4 quality control samples should be
run even if only 1 compliance sample is run.
Generally, the number of quality control
samples that should be run are a multiple of
four with the minimum equal to the smallest
multiple of four that is greater than 5% of
the total number of samples to be run. For
example, if 300 compliance samples of an
analyte are run, then at least 16 quality control samples should be run (16 is the smallest
multiple of four that is greater than 15,
which is 5% of 300).
Control charts for each pool of an analyte
(and for each instrument in the laboratory
to be used for analysis of compliance samples) should be established by plotting F/T
versus date as the quality control sample results are reported. On the graph there should
be lines representing the control limits for
the pool, the mean F/T limits for the pool,
and the theoretical F/T of 1.000. Lines representing plus or minus (±) 2s√ should also be
represented on the charts. A theoretical example of a control chart is presented in Figure 1.
FIGURE 1—THEORETICAL EXAMPLE OF A CONTROL CHART FOR A POOL OF AN ANALYTE
1.162 (Upper Control Limit)
X
1.096 (Upper 2s√ Line)
X
X
X
1.000 (Theoretical Mean)
0.964 (Mean)
X
X
X
X
0.832 (Lower 2s√ Line)
X
X
0.766 (Lower Control Limit)
March
2
2
3
5
6
9
10
13
1 Note that the value,‘‘40%’’ may change
over time as experience is gained with the
program.
219
16
17
§ 1910.1027
All quality control samples should be plotted on the chart, and the charts should be
checked for visual trends. If a quality control sample falls above or below the control
limits for its pool, then corrective steps
must be taken (see the section on corrective
actions below). Once a laboratory’s program
has been established, control limits should
be updated every 2 months.
The updated control limits should be calculated from the results of the last 100 quality control samples run for each pool. If 100
quality control samples from a pool have not
been run at the time of the update, then the
limits should be based on as many as have
been run provided at least 20 quality control
samples from each pool have been run over 20
different days.
The trends that should be looked for on the
control charts are:
1. 10 consecutive quality control samples
falling above or below the mean;
2. 3 consecutive quality control samples
falling more than 2σ from the mean (above or
below the 2σ lines of the chart); or
3. the mean calculated to update the control limits falls more than 10% above or
below the theoretical mean of 1.000.
If any of these trends is observed, then all
analysis must be stopped, and an investigation into the causes of the errors must begin.
Before the analysis of compliance samples
may resume, the inadequacies must be remedied and the control limits must be reestablished for that pool of an analyte. Reestablishment of control limits will entail running 20 sets of quality control samples over
20 days.
Note that alternative procedures for defining internal quality control limits may also
be acceptable. Limits may be based, for example, on proficiency testing, such as ± 1 µg
or 15% of the mean (whichever is greater).
These should be clearly defined.
Corrective actions
Corrective action is the term used to describe the identification and remediation of
errors occurring within an analysis. Corrective action is necessary whenever the result
of the analysis of any quality control sample
falls outside of the established control limits. The steps involved may include simple
things like checking calculations of basic instrument maintenance, or it may involve
more complicated actions like major instrument repair. Whatever the source of error, it
must be identified and corrected (and a Corrective Action Report (CAR) must be completed. CARs should be kept on file by the
laboratory.
ATTACHMENT 2—CREATININE IN URINE (JAFFE
PROCEDURE)
Intended use: The CREA pack is used in
the Du Pont ACA discrete clinical analyzer
to quantitatively measure creatinine in
serum and urine.
Summary: The CREA method employs a
modification of the kinetic Jaffe reaction reported by Larsen. This method has been reported to be less susceptible than conventional methods to interference from non-creatinine, Jaffe-positive compounds.1
A split sample comparison between the
CREA method and a conventional Jaffe procedure on Autoanalyzer showed a good correlation. (See Specific Performance Characteristics).
* Note: Numbered subscripts refer to the
bibliography and lettered subscripts refer to
footnotes.
Autoanalyzer, is a registered trademark
of Technicon Corp., Tarrytown, NY.
Principles of Procedure: In the presence of
a strong base such as NaOH, picrate reacts
with creatinine to form a red chromophore.
The rate of increasing absorbance at 510 nm
due to the formation of this chromophore
during a 17.07-second measurement period is
directly proportional to the creatinine concentration in the sample.
Creatinine + Picrate  → Red chromophore (absorbs at 510 nm)
NaOH
Reagents:
Compartment a
No. 2, 3, &
4.
Form
Ingredient
Liquid
Picrate ......
Quantity b
Compartment a
Form
Ingredient
6 ................
Liquid
NaOH (for
pH adjustment) c.
0.11 mmol.
Quantity b
a. Compartments are numbered 1–7, with compartment #7 located closest to pack fill position #2.
b. Nominal value at manufacture.
c. See Precautions.
220
Precautions: Compartment #6 contains 75µ
L of 10 N NaOH; avoid contact; skin irritant;
rinse contacted area with water. Comply
with OSHA’S Bloodborne Pathogens Standard while handling biological samples (29
CFR 1910.1039).
Used packs contain human body fluids;
handle with appropriate care.
§ 1910.1027
FOR IN VITRO DIAGNOSTIC USE
Mixing and Diluting:
Mixing and diluting are automatically performed by the ACA discrete clinical analyzer. The sample cup must contain sufficient quantity to accommodate the sample
volume plus the ‘‘dead volume’’; precise cup
filling is not required.
SAMPLE CUP VOLUMES (µ L)
Standard
Microsystem
Analyzer
Dead
II, III ..........................................................................
IV, SX .......................................................................
V ...............................................................................
Total
120
120
90
Storage of Unprocessed Packs: Store at 2–
8 °C. Do not freeze. Do not expose to temperatures above 35 °C or to direct sunlight.
Expiration: Refer to EXPIRATION DATE
on the tray label.
Specimen Collection: Serum or urine can
be collected and stored by normal procedures.2
Known Interfering Substances 3
• Serum Protein Influence—Serum protein
levels exert a direct influence on the CREA
assay. The following should be taken into account when this method is used for urine
samples and when it is calibrated:
Aqueous creatinine standards or urine
specimens will give CREA results depressed
by approximately 0.7 mg/dL [62 µmol/L]d and
will be less precise than samples containing
more than 3 g/dL [30 g/L] protein.
Dead
3000
3000
3000
Total
10
30
10
500
500
500
All urine specimens should be diluted with
an albumin solution to give a final protein
concentration of at least 3 g/dL [30 g/L]. Du
Pont Enzyme Diluent (Cat. #790035–901) may
be used for this purpose.
• High concentration of endrogenous bilirubin (>20 mg/dL [>342 µmol/L]) will give depressed CREA results (average depression 0.8
mg/dL [71 µmol/L]).4
• Grossly hemolyzed (hemoglobin >100 mg/
dL [>62 µmol/L]) or visibly lipemic specimens
may cause falsely elevated CREA results.5,6
• The following cephalosporin antibiotics
do not interfere with the CREA method when
present at the concentrations indicated. Systematic inaccuracies (bias) due to these substances are less than or equal to 0.1 mg/dL
[8.84 µmol/L] at CREA concentrations of approximately 1 mg/dL [88 µmol/L].
Peak serum level
7,8,9
Drug concentration
Antibiotic
mg/dL
Cephaloridine .......................................................................
Cephalexin ...........................................................................
Cephamandole .....................................................................
Cephapirin ............................................................................
Cephradine ..........................................................................
Cefazolin ..............................................................................
• The following cephalosporin antibiotics
have been shown to affect CREA results
when present at the indicated concentra-
1.4
0.6–2.0
1.3–2.5
2.0
1.5–2.0
2.5–5.0
[mmol/L]
0.3
0.2–0.6
0.3–0.5
D0.4
0.4–0.6
0.55–1.1
mg/dL
[mmol/L]
25
25
25
25
25
50
6.0
7.2
4.9
5.6
7.1
11.0
tions. System inaccuracies (bias) due to
these substances are greater that 0.1 mg/dL
[8.84 µmol/L] at CREA concentrations of:
Peak serum level8,10
Drug concentration
Antibiotic
Cephalothin ......................................................
Cephoxitin ........................................................
mg/dL
[mmol/L]
1–6
2.0
0.2–1.5
0.5
221
mg/dL
100
5.0
[mmol/L]
25.2
1.2
Effect
↓20–25%
↑35–40%
§ 1910.1027
• The single wavelength measurement used
in this method eliminates interference from
chromophores whose 510 nm absorbance is
constant throughout the measurement period.
• Each laboratory should determine the acceptability of its own blood collection tubes
and serum separation products. Variations in
these products may exist between manufacturers and, at times, from lot to lot.
d. Systeme International d’unites (S.I.
Units) are in brackets.
Procedure:
TEST MATERIALS
Item
II, III Du Pont
Cat. No.
IV, SX Du
Pont Cat. No.
V Du Pont
Cat. No.
ACA CREA Analytical Test Pack ......................................
Sample System Kit or ..........................................................
Micro Sample System Kit and .............................................
Micro Sample System Holders ............................................
DYLUX Photosensitive ......................................................
Printer Paper ........................................................................
Thermal Printer Paper .........................................................
Du Pont Purified Water ........................................................
Cell Wash Solution ..............................................................
701976901
710642901
702694901
702785000
........................
700036000
NA
704209901
701864901
701976901
710642901
710356901
NA
........................
NA
710639901
710615901
710664901
701976901
713697901
NA
NA
........................
NA
713645901
710815901
710864901
Test Steps: The operator need only load
the sample kit and appropriate test pack(s)
into a properly prepared ACA discrete clinical analyzer. It automatically advances the
pack(s) through the test steps and prints a
result(s). See the Instrument Manual of the
ACA analyzer for details of mechanical
travel of the test pack(s).
Preset Creatinine (CREA)—Test Conditions
•
•
•
•
•
•
•
•
g. If the Du Pont Chemistry Controls are
being used, prepare them according to the instructions on the product insert sheets.
PRESET CREATININE (CREA) TEST CONDITIONS
Item
Count by ......
Sample Volume: 200 µ L
Diluent: Purified Water
Temperature: 37.0 ± 0.1 °C
Reaction Period: 29 seconds
Type of Measurement: Rate
Measurement Period: 17.07 seconds
Wavelength: 510 nm
Units: mg/dL [µmol/L]
CALIBRATION: The general calibration
procedure is described in the Calibration/
Verification chapter of the Manuals.
The following information should be considered when calibrating the CREA method.
• Assay Range: 0–20 mg/mL [0–1768 µmol/L] e.
• Reference Material: Protein containing
primary standards f or secondary calibrators such as Du Pont Elevated Chemistry Control (Cat. #790035903) and Normal
Chemistry Control (Cat.•#790035905)g.
• Suggested Calibration Levels: 1,5,20, mg/
mL [88, 442, 1768 µmol/L].
• Calibration Scheme: 3 levels, 3 packs per
level.
• Frequency: Each new pack lot. Every 3
months for any one pack lot.
e. For the results in S.I. units [µmol/L] the
conversion factory is 88.4.
f. Refer to the Creatinine Standard Preparation and Calibration Procedure available
on request from a Du Pont Representative.
Decimal Point
Location .......
Assigned
Starting.
Point or Offset Co.
Scale Factor
or Assigned.
Linear Term
C1 h.
ACA II analyzer
ACA III, IV, SX, V
analyzer
One (1) ...........
[Five (5)] .........
0.0 mg/dL .......
[000.0 µmol/L]
999.8 ..............
NA
000.0 mg/dL
[000 µmol/L]
¥1.000 E1
[9823.] ............
[¥8.840 E2]
0.2000 ............
mg/dL/count h ..
2.004 E-1 h
[0.3536 µmol/L/
count].
[1.772E1]
h. The preset scale factor (linear term) was
derived from the molar absorptivity of the
indicator and is based on an absorbance to
activity relationship (sensitivity) of 0.596
(mA/min)/(U/L). Due to small differences in
filters and electronic components between
instruments, the actual scale factor (linear
term) may differ slightly from that given
above.
Quality Control: Two types of quality control procedures are recommended:
• General Instrument Check. Refer to the
Filter Balance Procedure and the Absorbance Test Method described in the ACA Analyzer Instrument Manual. Refer also to the
ABS Test Methodology literature.
• Creatinine Method Check. At least once
daily run a CREA test on a solution of
222
known creatinine activity such as an assayed control or calibration standard other
than that used to calibrate the CREA method. For further details review the Quality
Assurance Section of the Chemistry Manual.
The result obtained should fall within acceptable limits defined by the day-to-day
variability of the system as measured in the
user’s laboratory. (See SPECIFIC PERFORMANCE CHARACTERISTICS for guidance.) If the result falls outside the laboratory’s acceptable limits, follow the procedure outlined in the Chemistry Troubleshooting Section of the Chemistry Manual.
A possible system malfunction is indicated
when analysis of a sample with five consecutive test packs gives the following results:
Level
SD
1 mg/dL ...........................................
[88 µmol/L] ......................................
20 mg/dL .........................................
[1768 µmol/L] ..................................
>0.15 mg/dL
[>13 µmol/L]
>0.68 mg/dL
[>60 µmol/L]
§ 1910.1027
code or word immediately following the numerical value should not be reported. Refer
to the Manual for the definition of error
codes.
Reference Interval
Serum: 11,
Males
i
0.8–1.3 md/dL
[71–115 µ mol/L]
0.6–1.0 md/dL
[53–88 µ mol/L]
Females
Urine: 12
Males
0.6–2.5 g/24 hr
[53–221 mmol/24 hr]
0.6–1.5 g/24 hr
[53–133 mmol/24 hr]
Females
i. Reference interval data obtained from
200 apparently healthy individuals (71 males,
129 females) between the ages of 19 and 72.
Each laboratory should establish its own
reference intervals for CREA as performed
on the analyzer.
Specific Performance Characteristics
Refer to the procedure outlined in the
Trouble Shooting Section of the Manual.
Results: The ACA analyzer automatically
calculates and prints the CREA result in mg/
dL [µmol/L].
Standard deviation (%
CV)
Material
Mean
Within-run
Limitation of Procedure: Results >20 mg/dL
[1768 µmol/L]:
• Dilute with suitable protein base diluent.
Reassay. Correct for diluting before reporting.
The reporting system contains error messages to warn the operator of specific malfunctions. Any report slip containing a letter
j
REPRODUCIBILITY k
Lyophilized ...
Control
Lyophilized ...
Control
Betweenday
1.3
[115]
0.05 (3.7)
[4.4]
0.05 (3.7)
[4.4]
20.6
[1821]
0.12 (0.6)
[10.6]
0.37 (1.8)
[32.7]
CORRELATION—REGRESSION STATISTICS l
Comparative method
Slope
Autoanalyzer ....................................................................
j. All specific performance characteristics
tests were run after normal recommended
equipment quality control checks were performed (see Instrument Manual).
k. Specimens at each level were analyzed
in duplicate for twenty days. The within-run
1.03
Intercept
0.03[2.7]
Correlation
coefficient
0.997
n
260
and between-day standard deviations were
calculated by the analysis of variance method.
l. Model equation for regression statistics
is:
Result of ACA  Analyzer = Slope (Comparative method result) + intercept
Assay Range m
0.0–20.0 mg/dl
[0–1768 µmol]
m. See REPRODUCIBILITY for method
performance within the assay range.
223
§ 1910.1027
Analytical Specificity
See
KNOWN
INTERFERING
STANCES section for details.
SUB-
BIBLIOGRAPHY
1 Larsen,
K, Clin Chem Acta 41, 209 (1972).
2 Tietz,
NW, Fundamentals of Clinical
Chemistry, W. B. Saunders Co., Philadelphia,
PA, 1976, pp 47–52, 1211.
3 Supplementary information pertaining to
the effects of various drugs and patient conditions on in vivo or in vitro diagnostic levels can be found in ‘‘Drug Interferences with
Clinical Laboratory Tests,’’ Clin. Chem 21 (5)
(1975), and ‘‘Effects of Disease on Clinical
Laboratory Tests,’’ Clin Chem, 26 (4) 1D–476D
(1980).
4 Watkins, R. Fieldkamp, SC, Thibert, RJ,
and Zak, B, Clin Chem, 21, 1002 (1975).
5 Kawas, EE, Richards, AH, and Bigger, R,
An Evaluation of a Kinetic Creatinine Test
for the Du Pont ACA, Du Pont Company,
Wilmington, DE (February 1973). (Reprints
available from DuPont Company, Diagnostic
Systems)
6 Westgard, JO, Effects of Hemolysis and
Lipemia on ACA Creatinine Method, 0.200 µL,
Sample Size, Du Pont Company, Wilmington, DE (October 1972).
7 Physicians’ Desk Reference, Medical Economics Company, 33 Edition, 1979.
8 Henry, JB, Clinical Diagnosis and Management by Laboratory Methods, W.B. Saunders Co., Philadelphia, PA 1979, Vol. III.
9 Krupp, MA, Tierney, LM Jr., Jawetz, E,
Roe, RI, Camargo, CA, Physicians Handbook,
Lange Medical Publications, Los Altos, CA,
1982 pp 635–636.
10 Sarah,
AJ, Koch, TR, Drusano, GL,
Celoxitin Falsely Elevates Creatinine Levels,
JAMA 247, 205–206 (1982).
11 Gadsden, RH, and Phelps, CA, A Normal
Range Study of Amylase in Urine and Serum
on the Du Pont ACA, Du Pont Company, Wilmington, DE (March 1978). (Reprints available from DuPont Company, Diagnostic Systems)
12 Dicht, JJ, Reference Intervals for Serum
Amylase and Urinary Creatinine on the Du
Pont ACA Discrete Clinical Analyzer, Du
Pont Company, Wilmington, DE (November
1984).
ATTACHMENT 3—ANALYSIS OF CREATININE FOR
THE NORMALIZATION OF CADMIUM AND BETA–
2–MICROGLOBULIN CONCENTRATIONS IN URINE
(OSLTC PROCEDURE).
Matrix: Urine.
Target concentration: 1.1 g/L (this amount
is representative of creatinine concentrations found in urine).
Procedure: A 1.0 mL aliquot of urine is
passed through a C18 SEP-PAK (Waters Associates). Approximately 30 mL of HPLC
(high performance liquid chromatography)
grade water is then run through the SEP-
PAK. The resulting solution is diluted to
volume in a 100-mL volumetric flask and
analyzed by HPLC using an ultraviolet (UV)
detector.
Special requirements: After collection,
samples should be appropriately stabilized
for cadmium (Cd) analysis by using 10% high
purity (with low Cd background levels) nitric
acid (exactly 1.0 mL of 10% nitric acid per 10
mL of urine) or stabilized for Beta-2–Microglobulin (B2M) by taking to pH 7 with dilute
NaOH (exactly 1.0 mL of 0.11 N NaOH per 10
mL of urine). If not immediately analyzed,
the samples should be frozen and shipped by
overnight mail in an insulated container.
Dated: January 1992.
David B. Armitage,
Duane Lee,
Chemists.
Organic Service Branch II, OSHA Technical
Center, Salt Lake City, Utah
1. General Discussion
1.1 Background
1.1.1. History of procedure
Creatinine has been analyzed by several
methods in the past. The earliest methods were of the wet chemical type. As an
example, creatinine reacts with sodium
picrate in basic solution to form a red
complex,
which
is
then
analyzed
colorimetrically (Refs. 5.1. and 5.2.).
Since industrial hygiene laboratories will
be analyzing for Cd and B2M in urine,
they will be normalizing those concentrations to the concentration of creatinine in urine. A literature search revealed several HPLC methods (Refs. 5.3.,
5.4., 5.5. and 5.6.) for creatinine in urine
and because many industrial hygiene laboratories have HPLC equipment, it was
desirable to develop an industrial hygiene HPLC method for creatinine in
urine. The method of Hausen, Fuchs, and
Wachter was chosen as the starting point
for method development. SEP-PAKs were
used for sample clarification and cleanup
in this method to protect the analytical
column. The urine aliquot which has
been passed through the SEP-PAK is
then analyzed by reverse-phase HPLC
using ion-pair techniques.
This method is very similar to that of
Ogata and Taguchi (Ref. 5.6.), except
they used centrifugation for sample
clean-up. It is also of note that they did
a comparison of their HPLC results to
those of the Jaffe method (a picric acid
method commonly used in the health
care industry) and found a linear relationship of close to 1:1. This indicates
that either HPLC or colorimetric methods may be used to measure creatinine
concentrations in urine.
1.1.2. Physical properties (Ref. 5.7.)
224
Molecular weight: 113.12
Molecular formula: C4–H7–N3–0
Chemical name: 2-amino-1,5-dihydro-1-methyl-4H-imidazol-4-one
CAS No.: 60–27–5
Melting point: 300 °C (decomposes)
Appearance: white powder
Solubility: soluble in water; slightly soluble
in alcohol; practically insoluble in acetone, ether, and chloroform
Synonyms:
1-methylglycocyamidine,
1methylhydantoin-2-imide
Structure: see Figure #1
1.2. Advantages
1.2.1. This method offers a simple, straightforward, and specific alternative method
to the Jaffe method.
1.2.2. HPLC instrumentation is commonly
found in many industrial hygiene laboratories.
1.0 mL of 10% nitric acid to 10 mL of
urine.
2.3.2. After sample collection seal the plastic bottle securely and wrap it with an
appropriate seal. Urine samples should be
frozen and then shipped by overnight
mail (if shipping is necessary) in an insulated container. (Do not fill plastic bottle too full. This will allow for expansion
of contents during the freezing process.)
2.4. The Effect of Preparation and Stabilization Techniques on Creatinine Concentrations
Three urine samples were prepared by
making one sample acidic, not treating a
second sample, and adjusting a third
sample to pH 7. The samples were analyzed in duplicate by two different procedures. For the first procedure a 1.0 mL
aliquot of urine was put in a 100-mL volumetric flask, diluted to volume with
HPLC grade water, and then analyzed directly on an HPLC. The other procedure
used SEP-PAKs. The SEP-PAK was
rinsed with approximately 5 mL of methanol followed by approximately 10 mL of
HPLC grade water and both rinses were
discarded. Then, 1.0 mL of the urine sample was put through the SEP-PAK, followed by 30 mL of HPLC grade water.
The urine and water were transferred to
a 100-mL volumetric flask, diluted to volume with HPLC grade water, and analyzed by HPLC. These three urine samples were analyzed on the day they were
obtained and then frozen. The results
show that whether the urine is acidic,
untreated or adjusted to pH 7, the resulting answer for creatinine is essentially
unchanged. The purpose of stabilizing
the urine by making it acidic or neutral
is for the analysis of Cd or B2M respectively.
2. Sample stabilization procedure
2.1. Apparatus
Metal-free plastic container for urine sample.
2.2. Reagents
2.2.1. Stabilizing Solution—
(1) Nitric acid (10%, high purity with low
Cd background levels) for stabilizing
urine for Cd analysis or
(2) NaOH, 0.11 N, for stabilizing urine for
B2M analysis.
2.2.2. HPLC grade water
2.3. Technique
2.3.1. Stabilizing solution is added to the
urine sample (see section 2.2.1.). The stabilizing solution should be such that for
each 10 mL of urine, add exactly 1.0 mL
of stabilizer solution. (Never add water
or urine to acid or base. Always add acid
or base to water or urine.) Exactly 1.0
mL of 0.11 N NaOH added to 10 mL of
urine should result in a pH of 7. Or add
§ 1910.1027
COMPARISON OF PREPARATION
TECHNIQUES
Sample
Acid .....................................
Acid .....................................
Untreated .............................
Untreated .............................
pH 7 .....................................
pH 7 .....................................
&
STABILIZATION
w/o SEPPAK g/L
creatinine
with SEPPAK g/L
creatinine
1.10
1.11
1.12
1.11
1.08
1.11
1.10
1.10
1.11
1.12
1.02
1.08
2.5. Storage
After 4 days and 54 days of storage in a
freezer, the samples were thawed,
brought to room temperature and analyzed using the same procedures as in
section 2.4. The results of several days of
storage show that the resulting answer of
creatinine is essentially unchanged.
225
§ 1910.1027
STORAGE DATA
4 days
Sample
w/o SEPPAK g/L
creatinine
with SEPPAK g/L
creatinine
Acid ..........................................................................
Acid ..........................................................................
Acid ..........................................................................
Untreated .................................................................
Untreated .................................................................
Untreated .................................................................
pH 7 .........................................................................
pH 7 .........................................................................
pH 7 .........................................................................
1.09
1.10
....................
1.13
1.15
....................
1.14
1.14
....................
1.09
1.10
....................
1.14
1.14
....................
1.13
1.13
....................
2.6. Interferences
None.
2.7. Safety precautions
2.7.1. Make sure samples are properly
sealed and frozen before shipment to
avoid leakage.
2.7.2. Follow the appropriate shipping procedures.
The following modified special safety precautions are based on those recommended by the Centers for Disease
Control (CDC) (Ref. 5.8.). and OSHA’s
Bloodborne Pathogens standard (29 CFR
1910.1039).
2.7.3. Wear gloves, lab coat, and safety
glasses while handling all human urine
products. Disposable plastic, glass, and
paper (pipet tips, gloves, etc.) that contact urine should be placed in a biohazard autoclave bag. These bags should
be kept in appropriate containers until
sealed and autoclaved. Wipe down all
work surfaces with 10% sodium hypochlorite solution when work is finished.
2.7.4. Dispose of all biological samples and
diluted specimens in a biohazard autoclave bag at the end of the analytical
run.
2.7.5. Special care should be taken when
handling and dispensing nitric acid. Always remember to add acid to water (or
urine). Nitric acid is a corrosive chemical capable of severe eye and skin damage. Wear metal-free gloves, a lab coat,
and safety glasses. If the nitric acid
comes in contact with any part of the
body, quickly wash with copious quantities of water for at least 15 minutes.
2.7.6. Special care should be taken when
handling and dispensing NaOH. Always
remember to add base to water (or
urine). NaOH can cause severe eye and
skin damage. Always wear the appropriate gloves, a lab coat, and safety
glasses. If the NaOH comes in contact
with any part of the body, quickly wash
54 days
w/o SEPPAK g/L
creatinine
1.08
1.09
1.09
1.09
1.10
1.09
1.12
1.12
1.12
with SEPPAK g/L
creatinine
1.09
1.10
1.09
1.11
1.10
1.10
1.12
1.12
1.12
with copious quantities of water for at
least 15 minutes.
3. Analytical procedure
3.1. Apparatus
3.1.1. A high performance liquid chromatograph equipped with pump, sample
injector and UV detector.
3.1.2. A C18 HPLC column; 25 cm x 4.6 mm
I.D.
3.1.3. An electronic integrator, or some
other suitable means of determining
analyte response.
3.1.4. Stripchart recorder.
3.1.5. C18 SEP-PAKs (Waters Associates) or
equivalent.
3.1.6. Luer-lock syringe for sample preparation (5 mL or 10 mL).
3.1.7. Volumetric pipettes and flasks for
standard and sample preparation.
3.1.8. Vacuum system to aid sample preparation (optional).
3.2. Reagents
3.2.1. Water, HPLC grade.
3.2.2. Methanol, HPLC grade.
3.2.3. PIC B–7 (Waters Associates) in small
vials.
3.2.4.
Creatinine,
anhydrous,
Sigma
hemical Corp., purity not listed.
3.2.5. 1–Heptanesulfonic acid, sodium salt
monohydrate.
3.2.6. Phosphoric acid.
3.2.7. Mobile phase. It can be prepared by
mixing one vial of PIC B–7 into a 1 L solution of 50% methanol and 50% water.
The mobile phase can also be made by
preparing a solution that is 50% methanol and 50% water with 0.005M
heptanesulfonic acid and adjusting the
pH of the solution to 3.5 with phosphoric
acid.
3.3. Standard preparation
3.3.1. Stock standards are prepared by
weighing 10 to 15 mg of creatinine. This
is transferred to a 25-mL volumetric
flask and diluted to volume with HPLC
grade water.
226
3.3.2. Dilutions to a working range of 3 to
35 µg/mL are made in either HPLC grade
water or HPLC mobile phase (standards
give the same detector response in either
solution).
3.4. Sample preparation
3.4.1. The C18 SEP-PAK is connected to a
Luer-lock syringe. It is rinsed with 5 mL
HPLC grade methanol and then 10 mL of
HPLC grade water. These rinses are discarded.
3.4.2. Exactly 1.0 mL of urine is pipetted
into the syringe. The urine is put
through the SEP-PAK into a suitable
container using a vacuum system.
3.4.3. The walls of the syringe are rinsed in
several stages with a total of approximately 30 mL of HPLC grade water.
§ 1910.1027
These rinses are put through the SEPPAK into the same container. The resulting solution is transferred to a 100-mL
volumetric flask and then brought to
volume with HPLC grade water.
3.5. Analysis (conditions and hardware are
those used in this evaluation.)
3.5.1. Instrument conditions
Column: Zorbax ODS, 5–6 µm particle size;
25 cm x 4.6 mm I.D.
Mobile phase: See Section 3.2.7.
Detector: Dual wavelength UV; 229 nm (primary) 254 nm (secondary)
Flow rate: 0.7 mL/ minute
Retention time: 7.2 minutes
Sensitivity: 0.05 AUFS
Injection volume: 20µl
3.5.2. Chromatogram (see Figure #2)
227
§ 1910.1027
3.6. Interferences
3.6.1. Any compound that has the same retention time as creatinine and absorbs at
229 nm is an interference.
3.6.2. HPLC conditions may be varied to
circumvent interferences. In addition,
analysis at another UV wavelength (i.e.
254 nm) would allow a comparison of the
ratio of response of a standard to that of
a sample. Any deviations would indicate
an interference.
3.7. Calculations
228
3.7.1. A calibration curve is constructed by
plotting detector response versus standard concentration (See Figure #3).
229
§ 1910.1027
3.7.2. The concentration of creatinine in a
sample is determined by finding the concentration corresponding to its detector
response. (See Figure #3).
§ 1910.1028
3.7.3. The µg/mL creatinine from section
3.7.2. is then multiplied by 100 (the dilution factor). This value is equivalent to
the micrograms of creatinine in the 1.0
mL stabilized urine aliquot or the milligrams of creatinine per liter of urine.
The desired units, g/L, is determined by
the following relationship:
µg A/g creatinine =
g/L =
µg/mL mg/L
=
1000
1000
3.7.4. The resulting value for creatinine is
used to normalize the urinary concentration of the desired analyte (A) (Cd or
B2M) by using the following formula.
µg A/L (experimental)
g/L creatinine
Where A is the desired analyte. The protocol
of reporting such normalized results is µg A/
g creatinine.
3.8. Safety precautions See section 2.7.
4. Conclusions
The determination of creatinine in urine
by HPLC is a good alternative to the Jaffe
method for industrial hygiene laboratories.
Sample clarification with SEP–PAKs did not
change the amount of creatinine found in
urine samples. However, it does protect the
analytical column. The results of this creatinine in urine procedure are unaffected by the
pH of the urine sample under the conditions
tested by this procedure. Therefore, no special measures are required for creatinine
analysis whether the urine sample has been
stabilized with 10% nitric acid for the Cd
analysis or brought to a pH of 7 with 0.11 N
NaOH for the B2M analysis.
5. References
5.1. Clark, L.C.; Thompson, H.L.; Anal. Chem.
1949, 21, 1218.
5.2. Peters, J.H.; J. Biol. Chem. 1942, 146, 176.
5.3. Hausen, V.A.; Fuchs, D.; Wachter, H.; J.
Clin. Chem. Clin. Biochem. 1981, 19, 373–378.
5.4. Clark, P.M.S.; Kricka L.J.; Patel, A.; J.
Liq. Chrom. 1980, 3(7), 1031–1046.
5.5. Ballerini, R.; Chinol, M.; Cambi, A.; J.
Chrom. 1979, 179, 365–369.
5.6. Ogata, M.; Taguchi, T.; Industrial Health
1987, 25, 225–228.
5.7. ‘‘Merck Index’’, 11th ed.; Windholz, Martha Ed.; Merck: Rahway, N.J., 1989; p 403.
5.8. Kimberly, M.; ‘‘Determination of Cadmium
in Urine by Graphite Furnace Atomic Absorption Spectrometry with Zeeman Background Correction.’’, Centers for Disease
Control, Atlanta, Georgia, unpublished,
update 1990.
[57 FR 42389, Sept. 14, 1992, as amended at 57
FR 49272, Oct. 30, 1992; 58 FR 21781, Apr. 23,
1993; 61 FR 5508, Feb. 13, 1996; 63 FR 1288, Jan.
8, 1998]
§ 1910.1028
Benzene.
(a) Scope and application. (1) This section applies to all occupational exposures to benzene. Chemical Abstracts
Service Registry No. 71–43–2, except as
provided in paragraphs (a)(2) and (a)(3)
of this section.
(2) This section does not apply to:
(i) The storage, transportation, distribution, dispensing, sale or use of
gasoline, motor fuels, or other fuels
containing benzene subsequent to its
final discharge from bulk wholesale
storage facilities, except that operations where gasoline or motor fuels
are dispensed for more than 4 hours per
day in an indoor location are covered
by this section.
(ii) Loading and unloading operations
at bulk wholesale storage facilities
which use vapor control systems for all
loading and unloading operations, except for the provisions of 29 CFR
1910.1200 as incorporated into this section and the emergency provisions of
paragraphs (g) and (i)(4) of this section.
(iii) The storage, transportation, distribution or sale of benzene or liquid
mixtures containing more than 0.1 percent benzene in intact containers or in
transportation pipelines while sealed
in such a manner as to contain benzene
vapors or liquid, except for the provisions of 29 CFR 1910.1200 as incorporated into this section and the emergency provisions of paragraphs (g) and
(i)(4) of this section.
(iv) Containers and pipelines carrying
mixtures with less than 0.1 percent
benzene and natural gas processing
plants processing gas with less than 0.1
percent benzene.
230
(v) Work operations where the only
exposure to benzene is from liquid mixtures containing 0.5 percent or less of
benzene by volume, or the vapors released from such liquids until September 12, 1988; work operations where
the only exposure to benzene is from
liquid mixtures containing 0.3 percent
or less of benzene by volume or the vapors released from such liquids from
September 12, 1988, to September 12,
1989; and work operations where the
only exposure to benzene is from liquid
mixtures containing 0.1 percent or less
of benzene by volume or the vapors released from such liquids after September 12, 1989; except that tire building machine operators using solvents
with more than 0.1 percent benzene are
covered by paragraph (i) of this section.
(vi) Oil and gas drilling, production
and servicing operations.
(vii) Coke oven batteries.
(3) The cleaning and repair of barges
and tankers which have contained benzene are excluded from paragraph (f)
methods of compliance, paragraph
(e)(1) exposure monitoring-general, and
paragraph (e)(6) accuracy of monitoring. Engineering and work practice
controls shall be used to keep exposures below 10 ppm unless it is proven
to be not feasible.
(b) Definitions.
Action level means an airborne concentration of benzene of 0.5 ppm calculated as an 8-hour time-weighted average.
specifically authorized by the employer
whose duties require the person to
enter a regulated area, or any person
purpose of exercising the right to observe monitoring and measuring procedures under paragraph (l) of this section, or any other person authorized by
the Act or regulations issued under the
Act.
Benzene (C6 H6) (CAS Registry No. 71–
43–2) means liquefied or gaseous benzene. It includes benzene contained in
liquid mixtures and the benzene vapors
§ 1910.1028
released by these liquids. It does not
include trace amounts of unreacted
benzene contained in solid materials.
Bulk wholesale storage facility means a
bulk terminal or bulk plant where fuel
is stored prior to its delivery to wholesale customers.
Container means any barrel, bottle,
can, cylinder, drum, reaction vessel,
storage tank, or the like, but does not
include piping systems.
Day means any part of a calendar
day.
Safety and Health, U.S. Department of
Health and Human Services, or designee.
Emergency means any occurrence
such as, but not limited to, equipment
failure, rupture of containers, or failure of control equipment which may or
does result in an unexpected significant release of benzene.
Employee exposure means exposure to
airborne benzene which would occur if
the employee were not using respiratory protective equipment.
Regulated area means any area where
airborne concentrations of benzene exceed or can reasonably be expected to
exceed, the permissible exposure limits, either the 8-hour time weighted average exposure of 1 ppm or the shortterm exposure limit of 5 ppm for 15
minutes.
Vapor control system means any equipment used for containing the total vapors displaced during the loading of
gasoline, motor fuel or other fuel tank
trucks and the displacing of these vapors through a vapor processing system
or balancing the vapor with the storage
tank. This equipment also includes systems containing the vapors displaced
from the storage tank during the unloading of the tank truck which balance the vapors back to the tank
truck.
(c) Permissible exposure limits (PELs)—
(1) Time-weighted average limit (TWA).
The employer shall assure that no employee is exposed to an airborne concentration of benzene in excess of one
part of benzene per million parts of air
(1 ppm) as an 8-hour time-weighted average.
231
§ 1910.1028
(2) Short-term exposure limit (STEL).
The employer shall assure that no employee is exposed to an airborne concentration of benzene in excess of five
(5) ppm as averaged over any 15 minute
period.
(d) Regulated areas. (1) The employer
shall establish a regulated area wherever the airborne concentration of benzene exceeds or can reasonably be expected to exceed the permissible exposure limits, either the 8-hour time
weighted average exposure of 1 ppm or
the short-term exposure limit of 5 ppm
for 15 minutes.
(2) Access to regulated areas shall be
limited to authorized persons.
(3) Regulated areas shall be determined from the rest of the workplace
in any manner that minimizes the
number of employees exposed to benzene within the regulated area.
(e) Exposure monitoring—(1) General.
(i) Determinations of employee exposure shall be made from breathing zone
air samples that are representative of
each employee’s average exposure to
airborne benzene.
(ii) Representative 8-hour TWA employee exposures shall be determined
on the basis of one sample or samples
representing the full shift exposure for
each job classification in each work
area.
(iii) Determinations of compliance
with the STEL shall be made from 15
minute employee breathing zone samples measured at operations where
there is reason to believe exposures are
high, such as where tanks are opened,
filled, unloaded or gauged; where containers or process equipment are
opened and where benzene is used for
cleaning or as a solvent in an uncontrolled situation. The employer may
use objective data, such as measurements from brief period measuring devices, to determine where STEL monitoring is needed.
(iv) Except for initial monitoring as
required under paragraph (e)(2) of this
section, where the employer can document that one shift will consistently
have higher employee exposures for an
operation, the employer shall only be
required to determine representative
employee exposure for that operation
during the shift on which the highest
exposure is expected.
(2) Initial monitoring. (i) Each employer who has a place of employment
covered under paragraph (a)(1) of this
section shall monitor each of these
workplaces and work operations to determine accurately the airborne concentrations of benzene to which employees may be exposed.
(ii) The initial monitoring required
under paragraph (e)(2)(i) of this section
shall be completed by 60 days after the
effective date of this standard or within 30 days of the introduction of benzene into the workplace. Where the employer has monitored within one year
prior to the effective date of this standard and the monitoring satisfies all
other requirements of this section, the
employer may rely on such earlier
monitoring results to satisfy the requirements of paragraph (e)(2)(i) of this
section.
(3) Periodic monitoring and monitoring
frequency. (i) If the monitoring required
by paragraph (e)(2)(i) of this section reveals employee exposure at or above
the action level but at or below the
TWA, the employer shall repeat such
monitoring for each such employee at
least every year.
(ii) If the monitoring required by
paragraph (e)(2)(i) of this section reveals employee exposure above the
TWA, the employer shall repeat such
monitoring for each such employee at
least every six (6) months.
(iii) The employer may alter the
monitoring schedule from every six
months to annually for any employee
for whom two consecutive measurements taken at least 7 days apart indicate that the employee exposure has
decreased to the TWA or below, but is
at or above the action level.
(iv) Monitoring for the STEL shall be
repeated as necessary to evaluate exposures of employees subject to short
term exposures.
(4) Termination of monitoring. (i) If the
initial monitoring required by paragraph (e)(2)(i) of this section reveals
employee exposure to be below the action level the employer may discontinue the monitoring for that employee, except as otherwise required by
paragraph (e)(5) of this section.
(ii) If the periodic monitoring required by paragraph (e)(3) of this section reveals that employee exposures,
232
as indicated by at least two consecutive measurements taken at least 7
days apart, are below the action level
the employer may discontinue the
monitoring for that employee, except
as otherwise required by paragraph
(e)(5).
(5) Additional monitoring. (i) The employer shall institute the exposure
(e)(2) and (e)(3) of this section when
there has been a change in the production, process, control equipment, personnel or work practices which may result in new or additional exposures to
benzene, or when the employer has any
reason to suspect a change which may
result in new or additional exposures.
(ii) Whenever spills, leaks, ruptures
or other breakdowns occur that may
lead to employee exposure, the employer shall monitor (using area or personal sampling) after the cleanup of
the spill or repair of the leak, rupture
or other breakdown to ensure that exposures have returned to the level that
existed prior to the incident.
(6) Accuracy of monitoring. Monitoring
shall be accurate, to a confidence level
of 95 percent, to within plus or minus
25 percent for airborne concentrations
of benzene.
(7) Employee notification of monitoring
results. (i) The employer shall, within
15 working days after the receipt of the
results of any monitoring performed
under this standard, notify each employee of these results in writing either
individually or by posting of results in
an appropriate location that is accessible to affected employees.
(ii) Whenever the PELs are exceeded,
the written notification required by
paragraph (e)(7)(i) of this section shall
contain the corrective action being
taken by the employer to reduce the
PEL, or shall refer to a document
available to the employee which states
the corrective actions to be taken.
(f) Methods of compliance—(1) Engineering controls and work practices. (i)
The employer shall institute engineering controls and work practices to reduce and maintain employee exposure
to benzene at or below the permissible
exposure limits, except to the extent
that the employer can establish that
these controls are not feasible or where
§ 1910.1028
the provisions of paragraph (f)(1)(iii) or
(g)(1) of this section apply.
(ii) Wherever the feasible engineering
controls and work practices which can
be instituted are not sufficient to reduce employee exposure to or below the
PELs, the employer shall use them to
reduce employee exposure to the lowest
levels achievable by these controls and
shall supplement them by the use of
respiratory protection which complies
with the requirements of paragraph (g)
of this section.
(iii) Where the employer can document that benzene is used in a workplace less than a total of 30 days per
year, the employer shall use engineering controls, work practice controls or
respiratory protection or any combination of these controls to reduce employee exposure to benzene to or below
the PELs, except that employers shall
use engineering and work practice controls, if feasible, to reduce exposure to
or below 10 ppm as an 8-hour TWA.
(2) Compliance program. (i) When any
exposures are over the PEL, the employer shall establish and implement a
written program to reduce employee
exposure to or below the PEL primarily by means of engineering and
work practice controls, as required by
paragraph (f)(1) of this section.
(ii) The written program shall include a schedule for development and
implementation of the engineering and
work practice controls. These plans
shall be reviewed and revised as appropriate based on the most recent exposure monitoring data, to reflect the
current status of the program.
(iii) Written compliance programs
shall be furnished upon request for examination and copying to the Assistant Secretary, the Director, affected
employees and designated employee
representatives.
(i) Periods necessary to install or implement feasible engineering and workpractice controls.
(ii) Work operations for which the
employer establishes that compliance
233
§ 1910.1028
with either the TWA or STEL through
the use of engineering and work-practice controls is not feasible; for example, some maintenance and repair activities, vessel cleaning, or other operations for which engineering and workpractice controls are infeasible because
exposures are intermittent and limited
in duration.
(iii) Work operations for which feasible engineering and work-practice
controls are not yet sufficient, or are
not required under paragraph (f)(1)(iii)
of this section, to reduce employee exposure to or below the PELs.
(iv) Emergencies.
(d)(1)(iii), (d)(3)(iii)(B)(1), and (2)), and
(f) through (m).
(ii) For air-purifying respirators, the
employer must replace the air-purifying element at the expiration of its
service life or at the beginning of each
shift in which such elements are used,
whichever comes first.
(iii) If NIOSH approves an air-purifying element with an end-of-servicelife indicator for benzene, such an element may be used until the indicator
shows no further useful life.
(3) Respirator selection. (i) The employer must select the appropriate respirator from Table 1 of this section.
(ii) Any employee who cannot use a
negative-pressure respirator must be
allowed to use a respirator with less
breathing resistance, such as a powered
air-purifying respirator or supplied-air
respirator.
TABLE 1—RESPIRATORY PROTECTION FOR BENZENE
Airborne concentration of benzene or condition of use
Respirator type
(a) Less than or equal to 10 ppm ...............
(b) Less than or equal to 50 ppm ...............
(1) Half-mask air-purifying respirator with organic vapor cartridge.
(1) Full facepiece respirator with organic vapor cartridges.
(1) Full facepiece gas mask with chin style canister.1
(1) Full facepiece powered air-purifying respirator with organic vapor canister.1
(1) Supplied air respirator with full facepiece in positive-pressure mode.
(1) Self-contained breathing apparatus with full facepiece in positive pressure
mode.
(2) Full facepiece positive-pressure supplied-air respirator with auxiliary self-contained air supply.
(1) Any organic vapor gas mask; or
(2) Any self-contained breathing apparatus with full facepiece.
(1) Full facepiece self-contained breathing apparatus in positive pressure mode.
(c) Less than or equal to 100 ppm .............
(d) Less than or equal to 1,000 ppm ..........
(e) Greater than 1,000 ppm or unknown
concentration.
(f) Escape ....................................................
(g) Firefighting .............................................
1 Canisters must have a minimum service life of four (4) hours when tested at 150 ppm benzene, at a flow rate of 64 LPM, 25
deg. C, and 85% relative humidity for non-powered air purifying respirators. The flow rate shall be 115 LPM and 170 LPM respectively for tight fitting and loose fitting powered air-purifying respirators.
(h) Protective clothing and equipment.
Personal protective clothing and equipment shall be worn where appropriate
to prevent eye contact and limit dermal exposure to liquid benzene. Protective clothing and equipment shall be
provided by the employer at no cost to
the employee and the employer shall
assure its use where appropriate. Eye
and face protection shall meet the requirements of 29 CFR 1910.133.
(i) Medical surveillance—(1) General. (i)
The employer shall make available a
medical surveillance program for employees who are or may be exposed to
benzene at or above the action level 30
or more days per year; for employees
who are or may be exposed to benzene
at or above the PELs 10 or more days
per year; for employees who have been
exposed to more than 10 ppm of benzene for 30 or more days in a year prior
to the effective date of the standard
when employed by their current employer; and for employees involved in
the tire building operations called tire
building machine operators, who use
solvents containing greater than 0.1
percent benzene.
all medical examinations and procedures are performed by or under the supervision of a licensed physician and
that all laboratory tests are conducted
by an accredited laboratory.
persons other than licensed physicians
234
who administer the pulmonary function testing required by this section
shall complete a training course in
spirometry sponsored by an appropriate governmental, academic or professional institution.
all examinations and procedures are
provided without cost to the employee
and at a reasonable time and place.
(2) Initial examination. (i) Within 60
days of the effective date of this standard, or before the time of initial assignment, the employer shall provide each
employee covered by paragraph (i)(1)(i)
of this section with a medical examination including the following elements:
(A) A detailed occupational history
which includes:
(1) Past work exposure to benzene or
any other hematological toxins,
(2) A family history of blood
dyscrasias including hematological
neoplasms;
(3) A history of blood dyscrasias including genetic hemoglobin abnormalities, bleeding abnormalities, abnormal
function of formed blood elements;
(4) A history of renal or liver dysfunction;
(5) A history of medicinal drugs routinely taken;
(6) A history of previous exposure to
ionizing radiation and
(7) Exposure to marrow toxins outside of the current work situation.
(B) A complete physical examination.
(C) Laboratory tests. A complete blood
count including a leukocyte count with
differential,
a
quantitative
thrombocyte count, hematocrit, hemoglobin, erythrocyte count and erythrocyte indices (MCV, MCH, MCHC).
The results of these tests shall be reviewed by the examining physician.
(D) Additional tests as necessary in
the opinion of the examining physician, based on alterations to the components of the blood or other signs
which may be related to benzene exposure; and
(E) For all workers required to wear
respirators for at least 30 days a year,
the physical examination shall pay special attention to the cardiopulmonary
system and shall include a pulmonary
function test.
(ii) No initial medical examination is
required to satisfy the requirements of
§ 1910.1028
paragraph (i)(2)(i) of this section if adequate records show that the employee
has been examined in accordance with
the procedures of paragraph (i)(2)(i) of
this section within the twelve months
prior to the effective date of this standard.
(3) Periodic examinations. (i) The employer shall provide each employee
covered under paragraph (i)(1)(i) of this
section with a medical examination annually following the previous examination. These periodic examinations shall
incude at least the following elements:
(A) A brief history regarding any new
exposure to potential marrow toxins,
changes in medicinal drug use, and the
appearance of physical signs relating
to blood disorders:
(B) A complete blood count including
a leukocyte count with differential,
quantitative thrombocyte count, hemoglobin,
hematocrit,
erythrocyte
count and erythrocyte indices (MCV,
MCH, MCHC); and
(C) Appropriate additional tests as
necessary, in the opinion of the examining physician, in consequence of alterations in the components of the
blood or other signs which may be related to benzene exposure.
(ii) Where the employee develops
signs and symptoms commonly associated with toxic exposure to benzene,
the employer shall provide the employee with an additional medical examination which shall include those
elements considered appropriate by the
examining physician.
(iii) For persons required to use respirators for at least 30 days a year, a
pulmonary function test shall be performed every three (3) years. A specific
evaluation of the cardiopulmonary system shall be made at the time of the
pulmonary function test.
(4) Emergency examinations. (i) In addition to the surveillance required by
(i)(1)(i), if an employee is exposed to
benzene in an emergency situation, the
employer shall have the employee provide a urine sample at the end of the
employee’s shift and have a urinary
phenol test performed on the sample
within 72 hours. The urine specific
gravity shall be corrected to 1.024.
(ii) If the result of the urinary phenol
test is below 75 mg phenol/L of urine,
no further testing is required.
235
§ 1910.1028
(iii) If the result of the urinary phenol test is equal to or greater than 75
mg phenol/L of urine, the employer
shall provide the employee with a complete blood count including an erythrocyte count, leukocyte count with differential and thrombocyte count at
monthly intervals for a duration of
three (3) months following the emergency exposure.
(iv) If any of the conditions specified
in paragraph (i)(5)(i) of this section exists, then the further requirements of
paragraph (i)(5) of this section shall be
met and the employer shall, in addition, provide the employees with periodic examinations if directed by the
physician.
(5) Additional examinations and referrals. (i) Where the results of the complete blood count required for the initial and periodic examinations indicate
any of the following abnormal conditions exist, then the blood count shall
be repeated within 2 weeks.
(A) The hemoglobin level or the hematocrit falls below the normal limit
[outside the 95% confidence interval
(C.I.)] as determined by the laboratory
for the particular geographic area and/
or these indices show a persistent
downward trend from the individual’s
pre-exposure norms; provided these
findings cannot be explained by other
medical reasons.
(B) The thrombocyte (platelet) count
varies more than 20 percent below the
employee’s most recent values or falls
outside the normal limit (95% C.I.) as
determined by the laboratory.
(C) The leukocyte count is below
4,000 per mm3 or there is an abnormal
differential count.
(ii) If the abnormality persists, the
examining physician shall refer the
employee to a hematologist or an internist for further evaluation unless
the physician has good reason to believe such referral is unnecessary. (See
Appendix C for examples of conditions
where a referral may be unnecessary.)
(iii) The employer shall provide the
hematologist or internist with the information required to be provided to
the physician under paragraph (i)(6) of
this section and the medical record required to be maintained by paragraph
(k)(2)(ii) of this section.
(iv) The hematologist’s or internist’s
evaluation shall include a determination as to the need for additional tests,
and the employer shall assure that
these tests are provided.
(i) A copy of this regulation and its
appendices;
(iii) The employee’s actual or representative exposure level:
protective equipment used or to be
used; and
(v) Information from previous employment-related medical examinations of the affected employee which is
not otherwise available to the examining physician.
(7) Physician’s written opinions. (i) For
each examination under this section,
the employer shall obtain and provide
the employee with a copy of the examining physician’s written opinion within 15 days of the examination. The
written opinion shall be limited to the
following information:
(A) The occupationally pertinent results of the medical examination and
tests;
(B) The physician’s opinion concerning whether the employee has any
detected medical conditions which
would place the employee’s health at
greater than normal risk of material
impairment from exposure to benzene;
(C) The physician’s recommended
limitations upon the employee’s exposure to benzene or upon the employee’s
use of protective clothing or equipment
and respirators.
and any medical conditions resulting
from benzene exposure which require
further explanation or treatment.
(ii) The written opinion obtained by
the employer shall not reveal specific
records, findings and diagnoses that
have no bearing on the employee’s ability to work in a benzene-exposed workplace.
236
(8) Medical removal plan. (i) When a
physician makes a referral to a hematologist/internist as required under
paragraph (i)(5)(ii) of this section, the
employee shall be removed from areas
where exposures may exceed the action
level until such time as the physician
makes a determination under paragraph (i)(8)(ii) of this section.
(ii) Following the examination and
evaluation by the hematologist/internist, a decision to remove an employee
from areas where benzene exposure is
above the action level or to allow the
employee to return to areas where benzene exposure is above the action level
shall be made by the physician in consultation with the hematologist/internist. This decision shall be communicated in writing to the employer and
employee. In the case of removal, the
physician shall state the required probable duration of removal from occupational exposure to benzene above the
action level and the requirements for
future medical examinations to review
the decision.
(iii) For any employee who is removed pursuant to paragraph (i)(8)(ii)
of this section, the employer shall provide a follow-up examination. The physician, in consultation with the hematologist/internist, shall make a decision within 6 months of the date the
employee was removed as to whether
the employee shall be returned to the
usual job or whether the employee
should be removed permanently.
(iv) Whenever an employee is temporarily removed from benzene exposure
pursuant to paragraph (i)(8)(i) or
(i)(8)(ii) of this section, the employer
shall transfer the employee to a comparable job for which the employee is
qualified (or can be trained for in a
short period) and where benzene exposures are as low as possible, but in no
event higher than the action level. The
employer shall maintain the employee’s current wage rate, seniority and
other benefits. If there is no such job
available, the employer shall provide
medical removal protection benefits
until such a job becomes available or
for 6 months, whichever comes first.
(v) Whenever an employee is removed
permanently from benzene exposure
based on a physician’s recommendation
pursuant to paragraph (i)(8)(iii) of this
§ 1910.1028
section, the employee shall be given
the opportunity to transfer to another
position which is available or later becomes available for which the employee is qualified (or can be trained
for in a short period) and where benzene exposures are as low as possible
but in no event higher than the action
level. The employer shall assure that
such employee suffers no reduction in
current wage rate, seniority or other
benefits as a result of the transfer.
(9) Medical removal protection benefits.
(i) The employer shall provide to an
employee 6 months of medical removal
protection benefits immediately following each occasion an employee is
removed from exposure to benzene because of hematological findings pursuant to paragraphs (i)(8) (i) and (ii) of
this section, unless the employee has
been transferred to a comparable job
where benzene exposures are below the
action level.
(ii) For the purposes of this section,
the requirement that an employer provide medical removal protection benefits means that the employer shall
maintain the current wage rate, seniority and other benefits of an employee
as though the employee had not been
removed.
(iii) The employer’s obligation to
provide medical removal protection
benefits to a removed employee shall
be reduced to the extent that the employee receives compensation for earnings lost during the period of removal
either from a publicly or employerfunded compensation program, or from
employment with another employer
made possible by virtue of the employee’s removal.
(j) Communication of benzene hazards
to employees—(1) Signs and labels. (i) The
employer shall post signs at entrances
to regulated areas. The signs shall bear
the following legend:
DANGER
BENZENE
CANCER HAZARD
FLAMMABLE—NO SMOKING
RESPIRATOR REQUIRED
lables or other appropriate forms of
warning are provided for containers of
benzene within the workplace. There is
237
§ 1910.1028
no requirement to label pipes. The labels shall comply with the requirements of 29 CFR 1910.1200(f) and in addition shall include the following legend:
DANGER
CONTAINS BENZENE
CANCER HAZARD
(2) Material safety data sheets. (i) Employers shall obtain or develop, and
shall provide access to their employees, to a material safety data sheet
(MSDS) which addresses benzene and
complies with 29 CFR 1910.1200.
(ii) Employers who are manufacturers or importers shall:
(A) Comply with paragraph (a) of this
section, and
(B) Comply with the requirement in
OSHA’s Hazard Communication Standard, 29 CFR 1910.1200, that they deliver
to downstream employers an MSDS
which addresses benzene.
(3) Information and training. (i) The
employer shall provide employees with
information and training at the time of
their initial assignment to a work area
where benzene is present. If exposures
are above the action level, employees
shall be provided with information and
training at least annually thereafter.
(ii) The training program shall be in
accordance with the requirements of 29
CFR 1910.1200(h) (1) and (2), and shall
include specific information on benzene
for each category of information included in that section.
(iii) In addition to the information
required under 29 CFR 1910.1200, the
employer shall:
(A) Provide employees with an explanation of the contents of this section,
including Appendices A and B, and indicate to them where the standard is
available; and
(B) Describe the medical surveillance
program required under paragraph (i)
of this section, and explain the information contained in Appendix C.
(k) Recordkeeping—(1) Exposure measurements. (i) The employer shall establish and maintain an accurate record of
all measurements required by paragraph (e) of this section, in accordance
with 29 CFR 1910.20.
(A) The dates, number, duration, and
results of each of the samples taken,
including a description of the procedure used to determine representative
employee exposures;
analytical methods used;
(C) A description of the type of respiratory protective devices worn, if
any; and
(D) The name, social security number, job classification and exposure levels of the employee monitored and all
other employees whose exposure the
measurement is intended to represent.
this record for at least 30 years, in accordance with 29 CFR 1910.20.
accurate record for each employee subject to medical surveillance required
by paragraph (i) of this section, in accordance with 29 CFR 1910.20.
(B) The employer’s copy of the physician’s written opinion on the initial,
periodic and special examinations, including results of medical examinations and all tests, opinions and recommendations;
(C) Any employee medical complaints related to exposure to benzene;
(D) A copy of the information provided to the physician as required by
paragraphs (i)(6) (ii) through (v) of this
section; and
(E) A copy of the employee’s medical
and work history related to exposure
to benzene or any other hematologic
toxins.
this record for at least the duration of
employment plus 30 years, in accordance with 29 CFR 1910.20.
assure that all records required to be
maintained by this section shall be
made available upon request to the Assistant Secretary and the Director for
(ii) Employee exposure monitoring
records required by this paragraph
shall be provided upon request for examination and copying to employees,
employee representatives, and the Assistant Secretary in accordance with 29
CFR 1910.20 (a) through (e) and (g)
through (i).
238
(iii) Employee medical records required by this paragraph shall be provided upon request for examination and
copying, to the subject employee, to
anyone having the specific written consent of the subject employee, and to
the Assistant Secretary in accordance
with 29 CFR 1910.20.
(4) Transfer of records. (i) The employer shall comply with the requirements involving transfer of records set
forth in 29 CFR 1019.20(h).
(ii) If the employer ceases to do business and there is no successor employer
to receive and retain the records for
the prescribed period, the employer
shall notify the Director, at least three
(3) months prior to disposal, and transmit them to the Director if required by
the Director within that period.
(l) Observation of monitoring—(1) Employee observation. The employer shall
provide affected employees, or their
designated representatives, an opportunity to observe the measuring or
monitoring of employee exposure to
benzene conducted pursuant to paragraph (e) of this section.
(2) Observation procedures. When observation of the measuring or monitoring of employee exposure to benzene
requires entry into areas where the use
of protective clothing and equipment
or respirators is required, the employer
shall provide the observer with personal protective clothing and equipment or respirators required to be worn
by employees working in the area, assure the use of such clothing and equipment or respirators, and require the
observer to comply with all other applicable safety and health procedures.
(m) Dates—(1) Effective date. The
standard shall become effective December 10, 1987.
(2) Start-up dates. (i) The requirements of paragraph (a) through (m) of
this section, except the engineering
control requirements of paragraph
(f)(1) of this section shall be completed
within sixty (60) days after the effective date of the standard.
(ii) Engineering and work practice
controls required by paragraph (f)(1) of
this section shall be implemented no
later than 2 years after the effective
date of the standard.
(iii) Coke and coal chemical operations may comply with paragraph
§ 1910.1028
(m)(2)(ii) of this section or alternately
include within the compliance program
required by paragraph (f)(2) of this section, a requirement to phase in engineering controls as equipment is repaired and replaced. For coke and coal
chemical operations choosing the latter alternative, compliance with the
engineering controls requirements of
paragraph (f)(1) of this section shall be
achieved no later than 5 years after the
effective date of this standard and substantial compliance with the engineering control requirements shall be
achieved within 3 years of the effective
date of this standard.
(n) Appendices. The information contained in Appendices A, B, C, and D is
not intended, by itself, to create any
imposed or to detract from any existing obligations. The protocols on respiratory fit testing in Appendix E are
mandatory.
SAFETY DATA SHEET, BENZENE
I. SUBSTANCE IDENTIFICATION
A. Substance: Benzene.
B. Permissible Exposure: Except as to the
use of gasoline, motor fuels and other fuels
subsequent to discharge from bulk terminals
and
other
exemptions
specified
in
§ 1910.1028(a)(2):
1. Airborne: The maximum time-weighted
average (TWA) exposure limit is 1 part of
benzene vapor per million parts of air (1
ppm) for an 8-hour workday and the maximum short-term exposure limit (STEL) is 5
ppm for any 15-minute period.
2. Dermal: Eye contact shall be prevented
and skin contact with liquid benzene shall be
limited.
C. Appearance and odor: Benzene is a clear,
colorless liquid with a pleasant, sweet odor.
The odor of benzene does not provide adequate warning of its hazard.
A. Ways in which benzene affects your
health. Benzene can affect your health if you
inhale it, or if it comes in contact with your
skin or eyes. Benzene is also harmful if you
happen to swallow it.
B. Effects of overexposure. 1. Short-term
(acute) overexposure: If you are overexposed
to high concentrations of benzene, well
above the levels where its odor is first recognizable, you may feel breathless, irritable,
euphoric, or giddy; you may experience irritation in eyes, nose, and respiratory tract.
239
§ 1910.1028
You may develop a headache, feel dizzy, nauseated, or intoxicated. Severe exposures may
lead to convulsions and loss of consciousness.
2. Long-term (chronic) exposure. Repeated
or prolonged exposure to benzene, even at
relatively low concentrations, may result in
various blood disorders, ranging from anemia
to leukemia, an irreversible, fatal disease.
Many blood disorders associated with benzene exposure may occur without symptoms.
III. PROTECTIVE CLOTHING AND EQUIPMENT
A. Respirators. Respirators are required for
those operations in which engineering controls or work practice controls are not feasible to reduce exposure to the permissible
level. However, where employers can document that benzene is present in the workplace less than 30 days a year, respirators
may be used in lieu of engineering controls.
If respirators are worn, they must have joint
Mine Safety and Health Administration and
the National Institute for Occupational Safety and Health (NIOSH) seal of approval, and
cartridge or canisters must be replaced before the end of their service life, or the end
of the shift, whichever occurs first. If you experience difficulty breathing while wearing a
respirator, you may request a positive pressure respirator from your employer. You
must be thoroughly trained to use the assigned respirator, and the training will be
provided by your employer.
B. Protective Clothing. You must wear appropriate protective clothing (such as boots,
gloves, sleeves, aprons, etc.) over any parts
of your body that could be exposed to liquid
benzene.
C. Eye and Face Protection. You must wear
splash-proof safety goggles if it is possible
that benzene may get into your eyes. In addition, you must wear a face shield if your
face could be splashed with benzene liquid.
IV. EMERGENCY AND FIRST AID PROCEDURES
A. Eye and face exposure. If benzene is
splashed in your eyes, wash it out immediately with large amounts of water. If irritation persists or vision appears to be affected see a doctor as soon as possible.
B. Skin exposure. If benzene is spilled on
your clothing or skin, remove the contaminated clothing and wash the exposed skin
with large amounts of water and soap immediately. Wash contaminated clothing before
you wear it again.
C. Breathing. If you or any other person
breathes in large amounts of benzene, get
the exposed person to fresh air at once.
Apply artificial respiration if breathing has
stopped. Call for medical assistance or a doctor as soon as possible. Never enter any vessel or confined space where the benzene concentration might be high without proper
safety equipment and at least one other per-
son present who will stay outside. A life line
should be used.
D. Swallowing. If benzene has been swallowed and the patient is conscious, do not induce vomiting. Call for medical assistance or
a doctor immediately.
V. MEDICAL REQUIREMENTS
If you are exposed to benzene at a concentration at or above 0.5 ppm as an 8-hour
time-weighted average, or have been exposed
at or above 10 ppm in the past while employed by your current employer, your employer is required to provide a medical examination and history and laboratory tests
within 60 days of the effective date of this
standard and annually thereafter. These
tests shall be provided without cost to you.
In addition, if you are accidentally exposed
to benzene (either by ingestion, inhalation,
or skin/eye contact) under emergency conditions known or suspected to constitute toxic
exposure to benzene, your employer is required to make special laboratory tests
available to you.
VI. OBSERVATION OF MONITORING
Your employer is required to perform
measurements that are representative of
your exposure to benzene and you or your
designated representative are entitled to observe the monitoring procedure. You are entitled to observe the steps taken in the
measurement procedure, and to record the
results obtained. When the monitoring procedure is taking place in an area where respirators or personal protective clothing and
equipment are required to be worn, you or
your representative must also be provided
with, and must wear the protective clothing
and equipment.
VII. ACCESS TO RECORDS
You or your representative are entitled to
see the records of measurements of your exposure to benzene upon written request to
your employer. Your medical examination
records can be furnished to yourself, your
physician or designated representative upon
request by you to your employer.
VIII. PRECAUTIONS FOR SAFE USE, HANDLING
AND STORAGE
Benzene liquid is highly flammable. It
should be stored in tightly closed containers
in a cool, well ventilated area. Benzene vapor
may form explosive mixtures in air. All
sources of ignition must be controlled. Use
nonsparking tools when opening or closing
benzene containers. Fire extinguishers,
where provided, must be readily available.
Know where they are located and how to operate them. Smoking is prohibited in areas
where benzene is used or stored. Ask your supervisor where benzene is used in your area
and for additional plant safety rules.
240
§ 1910.1028
3. Hazardous decomposition products:
Toxic gases and vapors (such as carbon monoxide).
TECHNICAL GUIDLINES, BENZENE
I. PHYSICAL AND CHEMICAL DATA
III. SPILL AND LEAK PROCEDURES
A. Substance identification.
1. Synonyms: Benzol, benzole, coal naphtha,
cyclohexatriene, phene, phenyl hydride,
pyrobenzol. (Benzin, petroleum benzin and
Benzine do not contain benzene).
2. Formula: C6 H6 (CAS Registry Number:
71–43–2)
B. Physical data.
1. Boiling Point (760 mm Hg); 80.1 ° C (176
° F)
2. Specific Gravity (water=1): 0.879
3. Vapor Density (air=1): 2.7
4. Melting Point: 5.5 ° C (42 ° F)
5. Vapor Pressure at 20 ° C (68 ° F): 75 mm
Hg
6. Solubility in Water: .06%
7. Evaporation Rate (ether=1): 2.8
8. Appearance and Odor: Clear, colorless
liquid with a distinctive sweet odor.
A. Steps to be taken if the material is released or spilled. As much benzene as possible should be absorbed with suitable materials, such as dry sand or earth. That remaining must be flushed with large amounts
of water. Do not flush benzene into a confined space, such as a sewer, because of explosion danger. Remove all ignition sources.
Ventilate enclosed places.
B. Waste disposal method. Disposal methods must conform to other jurisdictional regulations. If allowed, benzene may be disposed
of: (a) By absorbing it in dry sand or earth
and disposing in a sanitary landfill; (b) if
small quantities, by removing it to a safe location from buildings or other combustible
sources, pouring it in dry sand or earth and
cautiously igniting it; and (c) if large quantities, by atomizing it in a suitable combustion chamber.
II. FIRE, EXPLOSION, AND REACTIVITY HAZARD
DATA
A. Fire.
1. Flash Point (closed cup): ¥11 ° C (12 ° F)
2. Autoignition Temperature: 580 ° C (1076 °
F)
3. Flammable limits in Air. % by Volume:
Lower: 1.3%, Upper: 7.5%
4. Extinguishing Media: Carbon dioxide,
dry chemical, or foam.
5. Special Fire-Fighting procedures: Do not
use solid stream of water, since stream will
scatter and spread fire. Fine water spray can
be used to keep fire-exposed containers cool.
6. Unusual fire and explosion hazards: Benzene is a flammable liquid. Its vapors can
form explosive mixtures. All ignition sources
must be controlled when benzene is used,
handled, or stored. Where liquid or vapor
may be released, such areas shall be considered as hazardous locations. Benzene vapors
are heavier than air; thus the vapors may
travel along the ground and be ignited by
open flames or sparks at locations remote
from the site at which benzene is handled.
7. Benzene is classified as a 1 B flammable
liquid for the purpose of conforming to the
requirements of 29 CFR 1910.106. A concentration exceeding 3,250 ppm is considered
a potential fire explosion hazard. Locations
where benzene may be present in quantities
sufficient to produce explosive or ignitable
mixtures are considered Class I Group D for
the purposes of conforming to the requirements of 29 CFR 1910.309.
B. Reactivity.
1. Conditions contributing to instability:
Heat.
2. Incompatibility: Heat and oxidizing materials.
IV. MISCELLANEOUS PRECAUTIONS
A. High exposure to benzene can occur
when transferring the liquid from one container to another. Such operations should be
well ventilated and good work practices
must be established to avoid spills.
B. Use non-sparking tools to open benzene
containers which are effectively grounded
and bonded prior to opening and pouring.
C. Employers must advise employees of all
plant areas and operations where exposure to
benzene could occur. Common operations in
which high exposures to benzene may be encountered are: the primary production and
utilization of benzene, and transfer of benzene.
SURVEILLANCE GUIDELINES FOR BENZENE
I. ROUTE OF ENTRY
Inhalation; skin absorption.
II. TOXICOLOGY
Benzene is primarily an inhalation hazard.
Systemic absorption may cause depression of
the hematopoietic system, pancytopenia,
aplastic anemia, and leukemia. Inhalation of
high concentrations can affect central nervous system function. Aspiration of small
amounts of liquid benzene immediately
causes pulmonary edema and hemorrhage of
pulmonary tissue. There is some absorption
through the skin. Absorption may be more
rapid in the case of abraded skin, and benzene may be more readily absorbed if it is
present in a mixture or as a contaminant in
solvents which are readily absorbed. The
defatting action of benzene may produce primary irritation due to repeated or prolonged
241
§ 1910.1028
contact with the skin. High concentration
are irritating to the eyes and the mucuous
membranes of the nose, and respiratory
tract.
III. SIGNS AND SYMPTOMS
Direct skin contact with benzene may
cause erythema. Repeated or prolonged contact may result in drying, scaling dermatitis, or development of secondary skin infections. In addition, there is benzene absorption through the skin. Local effects of
benzene vapor or liquid on the eye are slight.
Only at very high concentrations is there
any smarting sensation in the eye. Inhalation of high concentrations of benzene may
have an initial stimulatory effect on the central nervous system characterized by exhilaration, nervous excitation, and/or giddiness,
followed by a period of depression, drowsiness, or fatigue. A sensation of tightness in
the chest accompanied by breathlessness
may occur and ultimately the victim may
lose consciousness. Tremors, convulsions and
death may follow from respiratory paralysis
or circulatory collapse in a few minutes to
several hours following severe exposures.
The detrimental effect on the blood-forming system of prolonged exposure to small
quantities of benzene vapor is of extreme importance. The hematopoietic system is the
chief target for benzene’s toxic effects which
are manifested by alterations in the levels of
formed elements in the peripheral blood.
These effects have occurred at concentrations of benzene which may not cause irritation of mucous membranes, or any unpleasant sensory effects. Early signs and symptoms of benzene morbidity are varied, often
not readily noticed and non-specific. Subjective complaints of headache, dizziness, and
loss of appetite may precede or follow clinical signs. Rapid pulse and low blood pressure, in addition to a physical appearance of
anemia, may accompany a subjective complaint of shortness of breath and excessive
tiredness. Bleeding from the nose, gums, or
mucous membranes, and the development of
purpuric spots (small bruises) may occur as
the condition progresses. Clinical evidence of
leukopenia, anemia, and thrombocytopenia,
singly or in combination, has been frequently reported among the first signs.
Bone marrow may appear normal, aplastic,
or hyperplastic, and may not, in all situations, correlate with peripheral blood forming tissues. Because of variations in the susceptibility to benzene morbidity, there is no
‘‘typical’’ blood picture. The onset of effects
of prolonged benzene exposure may be delayed for many months or years after the actual exposure has ceased and identification
or correlation with benzene exposure must
be sought out in the occupational history.
IV. TREATMENT OF ACUTE TOXIC EFFECTS
Remove from exposure immediately. Make
sure you are adequately protected and do not
risk being overcome by fumes. Give oxygen
or artificial resuscitation if indicated. Flush
eyes, wash skin if contaminated and remove
all contaminated clothing. Symptoms of intoxication may persist following severe exposures. Recovery from mild exposures is
usually rapid and complete.
V. SURVEILLANCE AND PREVENTIVE
CONSIDERATIONS
A. General
The principal effects of benzene exposure
which form the basis for this regulation are
pathological changes in the hematopoietic
system, reflected by changes in the peripheral blood and manifesting clinically as
pancytopenia, aplastic anemia, and leukemia. Consequently, the medical surveillance program is designed to observe, on a
regular basis, blood indices for early signs of
these effects, and although early signs of leukemia are not usually available, emerging
diagnostic technology and innovative regimes make consistent surveillance for leukemia, as well as other hematopoietic effects, essential.
Initial examinations are to be provided
within 60 days of the effective date of this
standard, or at the time of initial assignment, and periodic examinations annually
thereafter. There are special provisions for
medical tests in the event of hematologic abnormalities or for emergency situations.
The blood values which require referral to
a hematologist or internist are noted in the
standard in paragraph (i)(5). The standard
specifies that blood abnormalities that persist must be referred ‘‘unless the physician
has good reason to believe such referral is
unnecessary’’ (paragraph (i)(5)). Examples of
conditions that could make a referral unnecessary despite abnormal blood limits are
iron or folate deficiency, menorrhagia, or
blood loss due to some unrelated medical abnormality.
Symptoms and signs of benzene toxicity
can be non-specific. Only a detailed history
and appropriate investigative procedures
will enable a physician to rule out or confirm conditions that place the employee at
increased risk. To assist the examining physician with regard to which laboratory tests
are necessary and when to refer an employee
to the specialist, OSHA has established the
following guidelines.
B. Hematology Guidelines
A minimum battery of tests is to be performed by strictly standardized methods.
1. Red cell, white cell, platelet counts,
white blood cell differential, hematacrit and
242
red cell indices must be performed by an accredited laboratory. The normal ranges for
the red cell and white cell counts are influenced by altitude, race, and sex, and therefore should be determined by the accredited
laboratory in the specific area where the
tests are performed.
Either a decline from an absolute normal
or an individual’s base line to a subnormal
value or a rise to a supra-normal value, are
indicative of potential toxicity, particularly
if all blood parameters decline. The normal
total white blood count is approximately
7,200/mm 3 plus or minus 3,000. For cigarette
smokers the white count may be higher and
the upper range may be 2,000 cells higher
than normal for the laboratory. In addition,
infection, allergies and some drugs may raise
the white cell count. The normal platelet
count is approximately 250,000 with a range
of 140,000 to 400,000. Counts outside this range
should be regarded as possible evidence of
benzene toxicity.
Certain abnormalities found through routine screening are of greater significance in
the benzene-exposed worker and require
prompt consultation with a specialist, namely:
a. Thrombocytopenia.
b. A trend of decreasing white cell, red cell,
or platelet indices in an individual over time
is more worrisome than an isolated abnormal finding at one test time. The importance
of trend highlights the need to compare an
individual’s test results to baseline and/or
previous periodic tests.
c. A constellation or pattern of abnormalities in the different blood indices is of more
significance than a single abnormality. A
low white count not associated with any abnormalities in other cell indices may be a
normal statistical variation, whereas if the
low white count is accompanied by decreases
in the platelet and/or red cell indices, such a
pattern is more likely to be associated with
benzene toxicity and merits thorough investigation.
Anemia, leukopenia, macrocytosis or an
abnormal differential white blood cell count
should alert the physician to further investigate and/or refer the patient if repeat tests
confirm the abnormalities. If routine screening detects an abnormality, follow-up tests
which may be helpful in establishing the etiology of the abnormality are the peripheral
blood smear and the reticulocyte count.
The extreme range of normal for
reticulocytes is 0.4 to 2.5 percent of the red
cells, the usual range being 0.5 to 1.2 percent
of the red cells, but the typical value is in
the range of 0.8 to 1.0 percent. A decline in
reticulocytes to levels of less than 0.4 percent is to be regarded as possible evidence
(unless another specific cause is found) of
benzene toxicity requiring accelerated surveillance. An increase in reticulocyte levels
to about 2.5 percent may also be consistent
§ 1910.1028
with (but is not as characteristic of) benzene
toxicity.
2. An important diagnostic test is a careful
examination of the peripheral blood smear.
As with reticulocyte count the smear should
be with fresh uncoagulated blood obtained
from a needle tip following venipuncture or
from a drop of earlobe blood (capillary
blood). If necessary, the smear may, under
certain limited conditions, be made from a
blood sample anticoagulated with EDTA (but
never with oxalate or heparin). When the
smear is to be prepared from a specimen of
venous blood which has been collected by a
commercial Vacutainer  type tube containing neutral EDTA, the smear should be
made as soon as possible after the
venesection. A delay of up to 12 hours is permissible between the drawing of the blood
specimen into EDTA and the preparation of
the smear if the blood is stored at refrigerator (not freezing) temperature.
3. The minimum mandatory observations
to be made from the smear are:
a. The differential white blood cell count.
b. Description of abnormalities in the appearance of red cells.
c. Description of any abnormalities in the
platelets.
d. A careful search must be made throughout of every blood smear for immature white
cells such as band forms (in more than normal proportion, i.e., over 10 percent of the
total differential count), any number of
metamyelocytes, myelocytes or myeloblasts.
Any nucleate or multinucleated red blood
cells should be reported. Large ‘‘giant’’
platelets or fragments of megakaryocytes
must be recognized.
An increase in the proportion of band
forms among the neutrophilic granulocytes
is an abnormality deserving special mention,
for it may represent a change which should
be considered as an early warning of benzene
toxicity in the absence of other causative
factors (most commonly infection). Likewise, the appearance of metamyelocytes, in
the absence of another probable cause, is to
be considered a possible indication of benzene-induced toxicity.
An upward trend in the number of
basophils, which normally do not exceed
about 2.0 percent of the total white cells, is
to be regarded as possible evidence of benzene toxicity. A rise in the eosinophil count
is less specific but also may be suspicious of
toxicity if the rises above 6.0 percent of the
total white count.
The normal range of monocytes is from 2.0
to 8.0 percent of the total white count with
an average of about 5.0 percent. About 20 percent of individuals reported to have mild but
persisting abnormalities caused by exposure
to benzene show a persistent monocytosis.
The findings of a monocyte count which persists at more than 10 to 12 percent of the normal white cell count (when the total count is
243
§ 1910.1028
normal) or persistence of an absolute monocyte count in excess of 800/mm 3 should be regarded as a possible sign of benzene-induced
toxicity.
A less frequent but more serious indication
of benzene toxicity is the finding in the peripheral blood of the so-called ‘‘pseudo’’ (or
acquired) Pelger-Huet anomaly. In this
anomaly many, or sometimes the majority,
of the neutrophilic granulocytes possess two
round nuclear segements—less often one or
three round segments—rather than three
normally elongated segments. When this
anomaly is not hereditary, it is often but not
invariably predictive of subsequent leukemia. However, only about two percent of
patients who ultimately develop acute
myelogenous leukemia show the acquired
Pelger-Huet anomaly. Other tests that can
be administered to investigate blood abnormalities are discussed below; however, such
procedures should be undertaken by the hematologist.
An uncommon sign, which cannot be detected from the smear, but can be elicited by
a ‘‘sucrose water test’’ of peripheral blood, is
transient
paroxysmal
nocturnal
hemoglobinuria (PNH), which may first occur insidiously during a period of established
aplastic anemia, and may be followed within
one to a few years by the appearance of rapidly fatal acute myelogenous leukemia. Clinical detection of PNH, which occurs in only
one or two percent of those destined to have
acute myelogenous leukemia, may be difficult; if the ‘‘sucrose water test’’ is positive,
the somewhat more definitive Ham test, also
known as the acid-serum hemolysis test,
may provide confirmation.
e. Individuals documented to have developed acute myelogenous leukemia years
after initial exposure to benzene may have
progressed through a preliminary phase of
hematologic abnormality. In some instances
pancytopenia (i.e., a lowering in the counts
of all circulating blood cells of bone marrow
origin, but not to the extent implied by the
term ‘‘aplastic anemia’’) preceded leukemia
for many years. Depression of a single blood
cell type or platelets may represent a harbinger of aplasia or leukemia. The finding of
two or more cytopenias, or pancytopenia in
a benzene-exposed individual, must be regarded as highly suspicious of more advanced
although
still
reversible,
toxicity.
‘‘Pancytopenia’’ coupled with the appearance
of immature cells (myelocytes, myeloblasts,
erythroblasts, etc.), with abnormal cells
(pseudo Pelger-Huet anomaly, atypical nuclear heterochromatin, etc.), or unexplained
elevations of white blood cells must be regarded as evidence of benzene overexposure
unless proved otherwise. Many severely
aplastic patients manifested the ominous
finding of 5–10 percent myeloblasts in the
marrow,
occasional
myeloblasts
and
myelocytes in the blood and 20–30% mono-
cytes. It is evident that isolated cytopenias,
pancytopenias, and even aplastic anemias induced by benzene may be reversible and complete recovery has been reported on cessation of exposure. However, since any of
these abnormalities is serious, the employee
must immediately be removed from any possible exposure to benzene vapor. Certain
tests may substantiate the employee’s prospects for progression or regression. One such
test would be an examination of the bone
marrow, but the decision to perform a bone
marrow aspiration or needle biopsy is made
by the hematologist.
The findings of basophilic stippling in circulating red blood cells (usually found in 1 to
5% of red cells following marrow injury), and
detection in the bone marrow of what are
termed ‘‘ringed sideroblasts’’ must be taken
seriously, as they have been noted in recent
years to be premonitory signs of subsequent
leukemia.
Recently peroxidase-staining of circulating
or marrow neutrophil granulocytes, employing benzidine dihydrochloride, have revealed
the disappearance of, or diminution in, peroxidase in a sizable proportion of the
granulocytes, and this has been reported as
an early sign of leukemia. However, relatively few patients have been studied to
date. Granulocyte granules are normally
strongly peroxidase positive. A steady decline in leukocyte alkaline phosphatase has
also been reported as suggestive of early
acute leukemia. Exposure to benzene may
cause an early rise in serum iron, often but
not always associated with a fall in the
reticulocyte count. Thus, serial measurements of serum iron levels may provide a
means of determining whether or not there
is a trend representing sustained suppression
of erythropoiesis.
Measurement of serum iron, determination
of peroxidase and of alkaline phosphatase activity in peripheral granulocytes can be performed in most pathology laboratories. Peroxidase and alkaline phosphatase staining
are usually undertaken when the index of
suspecion for leukemia is high.
APPENDIX D TO § 1910.1028—SAMPLING
AND ANALYTICAL METHODS FOR BENZENE MONITORING AND MEASUREMENT PROCEDURES
Measurements taken for the purpose of determining employee exposure to benzene are
best taken so that the representative average 8-hour exposure may be determined from
a single 8-hour sample or two (2) 4-hour samples. Short-time interval samples (or grab
samples) may also be used to determine average exposure level if a minimum of five
measurements are taken in a random manner over the 8-hour work shift. Random sampling means that any portion of the work
shift has the same change of being sampled
244
as any other. The arithmetic average of all
such random samples taken on one work
shift is an estimate of an employee’s average
level of exposure for that work shift. Air
samples should be taken in the employee’s
breathing zone (air that would most nearly
represent that inhaled by the employee).
Sampling and analysis must be performed
with procedures meeting the requirements of
the standard.
There are a number of methods available
for monitoring employee exposures to benzene. The sampling and analysis may be performed by collection of the benzene vaptor or
charcoal absorption tubes, with subsequent
chemical analysis by gas chromatography.
Sampling and analysis may also be performed by portable direct reading instruments, real-time continuous monitoring systems, passive dosimeters or other suitable
methods. The employer has the obligation of
selecting a monitoring method which meets
the accuracy and precision requirements of
the standard under his unique field conditions. The standard requires that the method
of monitoring must have an accuracy, to a 95
percent confidence level, of not less than
plus or minus 25 percent for concentrations
of benzene greater than or equal to 0.5 ppm.
The OSHA Laboratory modified NIOSH
Method S311 and evaluated it at a benzene
air concentration of 1 ppm. A procedure for
determining the benzene concentration in
bulk material samples was also evalauted.
This work, reported in OSHA Laboratory
Method No. 12, includes the following two
analytical procedures:
I. OSHA Method 12 for Air Samples
Analyte: Benzene
Matrix: Air
Procedure:
Adsorption
on
charcoal,
desorption with carbon disulfide, analysis
by GC.
Detection limit: 0.04 ppm
Recommended air volume and sampling rate:
10L to 0.2 L/min.
1. Principle of the Method.
1.1 A known volume of air is drawn
through a charcoal tube to trap the organic
vapors present.
1.2. The charcoal in the tube is transferred
to a small, stoppered vial, and the anlyte is
desorbed with carbon disulfide.
1.3. An aliquot of the desorbed sample is injected into a gas chromatograph.
1.4 The area of the resulting peak is determined and compared with areas obtained
from standards.
2. Advantages and disadvantages of the
method.
2.1 The sampling device is small, portable,
and involved no liquids. Interferences are
minimal, and most of those which do occur
can
be
eliminated
by
altering
chromatographic conditions. The samples
§ 1910.1028
are analyzed by means of a quick, instrumental method.
2.2 The amount of sample which can be
taken is limited by the number of milligrams that the tube will hold before overloading. When the sample value obtained for
the backup section of the charcoal tube exceeds 25 percent of that found on the front
section, the possibility of sample loss exists.
3. Apparatus.
3.1 A calibrated personal sampling pump
whose flow can be determined within ±5 percent at the recommended flow rate.
3.2. Charcoal tubes: Glass with both ends
flame sealed, 7 cm long with a 6-mm O.D. and
a 4-mm I.D., containing 2 sections of 20/40
mesh activated charcoal separated by a 2mm portion of urethane foam. The activated
charcoal is prepared from coconut shells and
is fired at 600 °C prior to packing. The adsorbing section contains 100 mg of charcoal,
the back-up section 50 mg. A 3-mm portion of
urethane foam is placed between the outlet
end of the tube and the back-up section. A
plug of silanized glass wool is placed in front
of the adsorbing section. The pressure drop
across the tube must be less than one inch of
mercury at a flow rate of 1 liter per minute.
3.3. Gas chromatograph equipped with a
flame ionization detector.
3.4. Column (10-ft × 1⁄8-in stainless steel)
packed with 80/100 Supelcoport coated with
20 percent SP 2100, 0.1 percent CW 1500.
3.5. An electronic integrator or some other
suitable method for measuring peak area.
3.6. Two-milliliter sample vials with Teflon-lined caps.
3.7. Microliter syringes: 10-microliter (10µL syringe, and other convenient sizes for
making standards, 1-µL syringe for sample
injections.
3.8. Pipets: 1.0 mL delivery pipets
3.9. Volumetric flasks: convenient sizes for
making standard solutions.
4. Reagents.
4.1. Chromatographic quality carbon disulfide (CS2). Most commercially available carbon disulfide contains a trace of benzene
which must be removed. It can be removed
with the following procedure:
Heat under reflux for 2 to 3 hours, 500 mL
of carbon disulfide, 10 mL concentrated sulfuric acid, and 5 drops of concentrated nitric
acid.
The
benzene
is
converted
to
nitrobenzene. The carbon disulfide layer is
removed, dried with anhydrous sodium sulfate, and distilled. The recovered carbon disulfide should be benzene free. (It has recently been determined that benzene can
also be removed by passing the carbon disulfide through 13x molecular sieve).
4.2. Benzene, reagent grade.
4.3. p-Cymene, reagent grade, (internal
standard).
4.4. Desorbing reagent. The desorbing reagent is prepared by adding 0.05 mL of p-cymene per milliliter of carbon disulfide. (The
245
§ 1910.1028
internal standard offers a convenient means
correcting analytical response for slight inconsistencies in the size of sample injections. If the external standard technique is
preferred, the internal standard can be eliminated).
4.5. Purified GC grade helium, hydrogen
and air.
5. Procedure.
5.1. Cleaning of equipment. All glassware
used for the laboratory analysis should be
properly cleaned and free of organics which
could interfere in the analysis.
5.2. Calibration of personal pumps. Each
pump must be calibrated with a representative charcoal tube in the line.
5.3. Collection and shipping of samples.
5.3.1. Immediately before sampling, break
the ends of the tube to provide an opening at
least one-half the internal diameter of the
tube (2 mm).
5.3.2. The smaller section of the charcoal is
used as the backup and should be placed
nearest the sampling pump.
5.3.3. The charcoal tube should be placed in
a vertical position during sampling to minimize channeling through the charcoal.
5.3.4 Air being sampled should not be
passed through any hose or tubing before entering the charcoal tube.
5.3.5. A sample size of 10 liters is recommended. Sample at a flow rate of approximately 0.2 liters per minute. The flow rate
should be known with an accuracy of at least
±5 percent.
5.3.6. The charcoal tubes should be capped
with the supplied plastic caps immediately
after sampling.
5.3.7. Submit at least one blank tube (a
charcoal tube subjected to the same handling
procedures, without having any air drawn
through it) with each set of samples.
5.3.8. Take necessary shipping and packing
precautions to minimize breakage of samples.
5.4. Analysis of samples.
5.4.1. Preparation of samples. In preparation for analysis, each charcoal tube is
scored with a file in front of the first section
of charcoal and broken open. The glass wool
is removed and discarded. The charcoal in
the first (larger) section is transferred to a 2ml vial. The separating section of foam is removed and discarded; the second section is
transferred to another capped vial. These
two sections are analyzed separately.
5.4.2. Desorption of samples. Prior to analysis, 1.0 mL of desorbing solution is pipetted
into each sample container. The desorbing
solution consists of 0.05 µL internal standard
per mL of carbon disulfide. The sample vials
are capped as soon as the solvent is added.
Desorption should be done for 30 minutes
with occasional shaking.
5.4.3. GC conditions. Typical operating conditions for the gas chromatograph are:
1.30 mL/min (60 psig) helium carrier gas
flow.
2.30 mL/min (40 psig) hydrogen gas flow to
detector.
3.240 mL/min (40 psig) air flow to detector.
4.150 ° C injector temperature.
5.250 ° C detector temperature.
6.100 ° C column temperature.
5.4.4. Injection size. 1 µ L.
5.4.5. Measurement of area. The peak areas
are measured by an electronic integrator or
some other suitable form of area measurement.
5.4.6. An internal standard procedure is
used. The integrator is calibrated to report
results in ppm for a 10 liter air sample after
correction for desorption efficiency.
5.5. Determination of desorption efficiency.
5.5.1. Importance of determination. The
desorption efficiency of a particular compound can vary from one laboratory

29 CFR 1910 (continued, Section 1910.100 to end)

Transcription

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