Formaldehyde General information Key Points Fire

Transcription

Formaldehyde
General information
Key Points
Fire




Flammable
Reactive with strong oxidising agents, bases and acrylonitrile
Emits toxic fumes of carbon monoxide and carbon dioxide when heated to
decomposition; and hydrogen gas on reaction with strong bases
In the event of a fire involving formaldehyde, use alcohol resistant foam, or normal
foam if not available, and liquid tight protective clothing with breathing apparatus
Health






Due to its gaseous nature, inhalation and eye exposure are most likely
Possible carcinogen, toxic and corrosive
Inhalation of formaldehyde can lead to irritation of the nose, mouth and throat. In
severe cases, respiratory distress and swelling of the larynx and lungs may occur
Ingestion of formaldehyde can cause burns and ulcers in the stomach or intestines in
the early stages after ingestion. Chest or abdominal pain, sickness, diarrhoea and
haemorrhages in the stomach or intestines may also result. Other clinical features
include rapid breathing, yellowish discolouration of the skin, blood in the urine and
kidney failure
Exposure of the eyes to formaldehyde causes immediate stinging and burning with
spasm of the eyelids and tearing. High concentrations may cause burns to the cornea
Skin contact with concentrated formaldehyde gas can cause burns to the skin
Environment


Avoid release into the environment
Inform Environment Agency of substantial incidents
Prepared by J C Wakefield
CHAPD HQ, HPA
2008
Version 1
FORMALDEHYDE – GENERAL INFORMATION
Background
Formaldehyde is a colourless, corrosive,
flammable gas with a pungent, suffocating
odour. Formaldehyde may be present in the
environment from either natural or industrial
sources.
spasm of the eyelids and tearing. Exposure
to high concentrations may cause burns to
the cornea. Exposure of the skin to
formaldehyde causes irritation with burns to
the skin.
Formaldehyde is produced in large quantities
industrially. It is predominantly used
commercially as a solution in water at
concentrations in the range of 25 – 56 %
formaldehyde. Formaldehyde is a common
constituent used in the manufacture of many
complex materials. It is used in the
production of resin polymers for permanent
adhesives such as those used in fibreboard,
particle board, plywood and carpeting. It is
also used in foam insulation and as paper
and
textile
finishing
treatments.
Formaldehyde at approximately 5% in a
solution with water is used as a disinfectant
and fumigant in hospitals, ships, dwellings
and animal handling facilities, as it is
effective in killing most bacteria, viruses and
fungi.
Ingestion of formaldehyde solutions can
cause
burns
and
ulcers
to
the
gastrointestinal tract in the early stages after
ingestion. Formaldehyde ingestion may also
cause chest or abdominal pain, nausea,
vomiting, diarrhoea and gastrointestinal tract
haemorrhage. Other clinical features can
include
rapid
breathing,
yellowish
discolouration of the skin, blood in the urine
and kidney failure.
Formaldehyde
is
produced
in
the
atmosphere due to the degradation of
methane by sunlight. It is also released
during the combustion of organic materials,
and as such may be present in smoke from
wood fires, automobile emissions and
tobacco smoke. Small quantities of
formaldehyde may also be produced as a
product of metabolism by most organisms.
Formaldehyde is very toxic to humans. The
most common routes of exposure to
formaldehyde gas are either inhalation or
skin contact. However, solutions containing
formaldehyde may also be toxic following
ingestion.
Repeated or prolonged skin contact with
solutions of formaldehyde can give rise to
skin sensitisation (allergic contact dermatitis)
in some individuals, with symptoms such as
redness, itching, rash and swelling of the
skin.
Children exposed to formaldehyde would be
expected to display similar effects to those
seen in exposed adults. Exposure to
formaldehyde during pregnancy is not
expected to cause damage to the unborn
child at doses which do not cause adverse
effects to the mother.
Formaldehyde has been classified by the
International Agency for Research on Cancer
as carcinogenic to humans. It produces
nasal tumours following prolonged exposure
by inhalation to levels producing chronic
irritant effects.
Inhalation of formaldehyde gas will cause
irritation to the nose, mouth and throat and in
severe cases may cause respiratory distress
and swelling of the larynx and lungs.
Inhalation of formaldehyde may cause the
onset of asthma in sensitive individuals.
Exposure of the eyes to vapour or splashes
of formaldehyde solutions causes irritation
with immediate stinging and burning, with
General information: Page 2 of 5
Production and Uses
Key Points





Formaldehyde can occur naturally in the environment and is also produced
industrially
Formaldehyde is mainly used commercially as a solution in water
It is commonly used in the manufacture of resin polymers to produce permanent
adhesives, foam insulation and paper and textile finishing treatments
It is used as a disinfectant and fumigant in hospitals, ships, dwellings and animal
handling facilities.
Formaldehyde is also used to fix tissues for histology and pathology
Formaldehyde can occur naturally in the environment as it is produced from the breakdown
of methane by sunlight. Small quantities of formaldehyde may be produced as a product of
metabolism by most organisms including humans. Formaldehyde is also released during the
combustion of organic materials, and as such may be present in smoke from wood fires,
automobile emissions and tobacco smoke.
Formaldehyde is also produced in large quantities industrially. It is predominantly used
commercially as a solution in water at concentrations in the range of 25 – 56 %
formaldehyde. Formaldehyde is a common constituent used in the manufacture of many
complex materials. It is used in the production of polymers such as urea formaldehyde resin,
phenolic resins and melamine resin. A common use of these resins is in permanent
adhesives such as those used in fibreboard, particle board, plywood and carpeting. They are
also used in foam insulation and as paper and textile finishing treatments. Formaldehyde at
approximately 5% in a solution with water is used as a disinfectant and fumigant in hospitals,
ships, dwellings and animal handling facilities, as it is effective in killing most bacteria,
viruses and fungi. A solution of approximately 37% formaldehyde is commonly known as
formalin and is used as a tissue fixative for histology and pathology.
Frequently Asked Questions
What is formaldehyde?
Formaldehyde is a colourless, corrosive, flammable gas with a pungent, suffocating odour. It
may be present in the environment from either natural sources or it may be produced
industrially. The main use of formaldehyde is in the production of resins for permanent
adhesives used in fibreboard, particle board, plywood and carpeting. Formaldehyde has also
been used as a disinfectant and fumigant.
How does formaldehyde get into the environment?
Formaldehyde can occur naturally in the environment from the breakdown of methane by
sunlight. Formaldehyde is also released during the combustion of organic materials, and as
such may be present in smoke from wood fires, automobile emissions and tobacco smoke.
As formaldehyde is used industrially it may also enter the environment from workplaces
where it is manufactured or used.
How will I be exposed to formaldehyde?
The greatest potential for exposure to formaldehyde is in occupations where it is
manufactured or used. Anyone working with formaldehyde is at risk of inhaling the vapours if
there is insufficient ventilation or if adequate protective equipment is not used. People
working with formaldehyde are also at risk of getting splashes of it on their skin if they are not
adequately protected. Ingestion of significant amounts of formaldehyde is not a common
route of occupational exposure. As formaldehyde may also be present naturally in the
environment, individuals may come into contact with very low levels of formaldehyde in air.
If there is formaldehyde in the environment will I have any adverse health effects?
The presence of formaldehyde in the environment does not always lead to exposure. Clearly,
in order for it to cause any adverse health effects you must come into contact with it. You
may be exposed by breathing, eating, or drinking the substance or by skin contact. Following
exposure to any chemical, the adverse health effects you may encounter depend on several
factors, including the amount to which you are exposed (dose), the way you are exposed, the
duration of exposure, the form of the chemical and if you were exposed to any other
chemicals.
Inhalation of formaldehyde gas will cause irritation to the nose, mouth and throat and in
severe cases may cause respiratory distress and swelling of the larynx and lungs. Inhalation
of formaldehyde may cause the onset of asthma in sensitive individuals. Exposure of the
eyes to vapour or splashes of formaldehyde solutions causes irritation with immediate
stinging and burning, with spasm of the eyelids and tearing. Exposure to high concentrations
may cause burns to the cornea. Exposure of the skin to formaldehyde causes irritation with
burns to the skin. Ingestion of formaldehyde solutions can cause burns and ulcers to the
gastrointestinal tract in the early stages after ingestion. Formaldehyde ingestion may also
cause chest or abdominal pain, nausea, vomiting, diarrhoea and gastrointestinal tract
haemorrhage. Other clinical features can include rapid breathing, yellowish discolouration of
the skin, blood in the urine and kidney failure.
Can formaldehyde cause cancer?
Formaldehyde is known to be a cancer causing substance and has been classified by the
International Agency for Research on Cancer as carcinogenic to humans. It may produce
nasal cancer following repeated exposure via inhalation to levels that produce chronic
irritation. Exposure to lower levels for shorter periods is not considered to present any
carcinogenic risk.
Does formaldehyde affect children or damage the unborn child?
Children will be affected by formaldehyde in the same way as adults. However, the effects
seen in children may potentially be more severe.
Exposure of a pregnant mother to formaldehyde is not expected to cause damage to the
unborn child at amounts below that which cause significant health effects to the mother.
What should I do if I am exposed to formaldehyde?
It is very unlikely that the general population will be exposed to a level of formaldehyde high
enough to cause adverse health effects.
This document from the HPA Centre for Radiation, Chemical and Environmental Hazards reflects
understanding and evaluation of the current scientific evidence as presented and referenced in this
document.
Formaldehyde
Incident management
Key Points
Fire




Flammable
Reactive with strong oxidising agents, bases and acrylonitrile
Emits toxic fumes of carbon monoxide and carbon dioxide when heated to
decomposition; and hydrogen gas on reaction with strong bases
In the event of a fire involving formaldehyde, use alcohol resistant foam, or normal
foam if not available, and liquid tight protective clothing with breathing apparatus
Health
 Due to its gaseous nature, inhalation and ocular exposure are most likely
 Inhalation of formaldehyde can lead to irritation of the mucous membranes and
respiratory tract. In severe cases laryngeal and pulmonary oedema, pneumonitis and
acute respiratory distress syndrome may occur.
 Ingestion of concentrated formaldehyde solutions can cause burns and ulceration to
the GI tract. Common features are a burning sensation in the mouth and throat, chest
or abdominal pain, nausea, vomiting, diarrhoea and GI haemorrhage.
 Dermal exposure to formaldehyde solutions may cause skin irritation
 Formaldehyde is irritating to the eyes
Environment
 Avoid release into the environment
 Inform Environment Agency of substantial incidents
CRCE HQ, HPA
03/2012
Version 2
FORMALDEHYDE – INCIDENT MANAGEMENT
Hazard Identification
Standard (UK) Dangerous Goods Emergency Action Codes(a)
1198
Formaldehyde solution, flammable
EAC
●2W
Use alcohol resistant foam but, if not available, fine water
spray can be used. Wear liquid-tight chemical protective
clothing in combination with breathing apparatus*. Danger
that the substance can be violently or explosively reactive.
Spillages and decontamination run-off should be prevented
from entering drains and watercourses.
APP
A(fl)
Gas-tight chemical protective suit with breathing apparatus **
UN
Class
3
Flammable liquid
Sub
risks
8
Corrosive substance
Hazards
HIN
38
UN
2209
EAC
●2X
APP
-
Class
8
Sub
risks
-
Flammable liquid (flash point between 23oC and 60oC
inclusive), slightly corrosive or self-heating liquid, corrosive
Formaldehyde solution, with not less than 25 %
formaldehyde
Use alcohol resistant foam but, if not available, fine water
spray can be used. Wear liquid-tight chemical protective
clothing in combination with breathing apparatus*. Spillages
and decontamination run-off should be prevented from
entering drains and watercourses.
Corrosive substance
Hazards
HIN
80
Corrosive or slightly corrosive substance
UN – United Nations number; EAC – Emergency Action Code; APP – Additional Personal
Protection; HIN - Hazard Identification Number
a
Dangerous Goods Emergency Action Code List 2011. National Chemical Emergency Centre
(NCEC). The Stationary Office, London.
Incident management: Page 2 of 13
*Liquid-tight chemical protective clothing (BS 8428or EN 14605) in combination with selfcontained open circuit positive pressure compressed air breathing apparatus (BS EN 137).
** Gas-tight chemical protective clothing conforming to BS EN 943 part 2 in combination with
self-contained open circuit positive pressure compressed air breathing apparatus to BS EN
137.
Chemical Hazard Information and Packaging for Supply Classification(a)
Carc. Cat 3
Classification
T
Toxic
C
Corrosive
R23/24/25
Toxic by inhalation, in contact with skin and if swallowed
R34
Causes burns
R40
Limited evidence of a carcinogenic effect
R43
May cause sensitisation by skin contact
S1/2
Keep locked up and out of the reach of children
Risk phrases
S26
Safety phrases
Category 3 carcinogen
S36/37/39
S45
In case of contact with eyes, rinse immediately with plenty of
water and seek medical advice
Wear suitable protective clothing, gloves and eye/face
protection
In case of accident or if you feel unwell seek medical advice
immediately (show the label where possible)
Use only in well-ventilated areas
S51
Specific concentration limits
Concentration
Classification
C ≥25 %
T; R23/24/25
5 % ≤ C < 25 %
Xn; R20/21/22
C ≥25 %
C; R34
5 % ≤ C < 25 %
Xi; R36/37/38
C ≥ 0,2 %
R43
a
Annex VI to Regulation (EC) No 1272/2008 on Classification, Labelling and Packaging of
Substances and Mixtures- Table 3.2.
http://esis.jrc.ec.europa.eu/index.php?PGM=cla (accessed 03/2012)
Globally Harmonised System of Classification and Labelling of Chemicals
)
(GHS)(a
Carc. 2
Carcinogenicity, category 2
Acute Tox. 3
Acute toxicity, category 3
Skin Corr.
1B
Skin corrosion, category 1B
Skin Sens. 1
Skin sensitizer, category 1
Hazard Class
and Category
Hazard
Statement
Signal Words
H351
Suspected of causing cancer
H331
Toxic if inhaled
H311
Toxic in contact with skin
H301
Toxic if swallowed
H314
Causes severe skin burns and eye damage
H317
May cause an allergic skin reaction
DANGER
Implemented in the EU on 20 January 2009.
Specific concentration limits
Concentration
Hazard Class
and Category
C ≥ 25 %
Skin Corr. 1B
Hazard Statement
H314
Causes severe skin burns and eye
a
Annex VI to Regulation (EC) No 1272/2008 on Classification, Labelling and Packaging of
Substances and Mixtures- Table 3.1.
http://esis.jrc.ec.europa.eu/index.php?PGM=cla (accessed 03/2012)
damage
5 % ≤ C < 25 %
Skin Irrit. 2
H315
Causes skin irritation
5 % ≤ C < 25 %
Eye Irrit. 2
H319
Causes serious eye irritation
C≥5%
STOT SE 3
H335
May cause respiratory irritation
C ≥ 0,2 %
Skin Sens. 1
H317
May cause an allergic skin reaction
Physicochemical Properties
CAS number
50-00-0
Molecular weight
30
Empirical formula
CH2O
Common synonyms
Methanal; Methylene glycol; Oxomethane; Methylene oxide;
Methyl aldehyde
State at room temperature
Gas
Volatility
Vapour pressure 3,890 mm Hg at 25°C
Specific gravity
1.1 at 25°C (air = 1)
Flammability
Flammable
Lower explosive limit
7.0%
Upper explosive limit
73.0%
Water solubility
Soluble in water at 25°C
Reactivity
Reactive. Formaldehyde can react violently with strong oxidising
agents, causing risk of fire and explosion. Reacts with strong
bases, producing hydrogen gas which is flammable. Reacts
violently with acrylonitrile
Reaction or degradation
products
Releases toxic fumes of carbon monoxide and carbon dioxide
when heated to decomposition. Produces hydrogen gas on
reaction with strong bases
Odour
Pungent, suffocating
Structure
References
(a,b,c)
Formaldehyde (HAZARDTEXT® Hazard Management). In: Klasco RK (Ed): TOMES® System,
Thomson Micromedex, Greenwood Village, Colorado, USA. (electronic version). RightAnswer.com,
Inc., Midland, MI, USA, Available at: http://www.rightanswerknowledge.com/data/dt/dt149.htm
(accessed 01/2012).
b
The Merck Index (14th Edition). Entry 4235: Formaldehyde, 2006.
c
The Dictionary of Substances and their Effects. Ed. S Gangolli. Second Edition, Volume 4, 1999.
a
Threshold Toxicity Values
EXPOSURE VIA INHALATION
ppm
mg m-3
0.05
0.06
0.08 – 2.5
0.1 - 3
>5
>6
SIGNS AND SYMPTOMS
Slight eye irritation
a
Throat and upper respiratory tract
irritation
a
Lower airway and pulmonary irritation
a
a
International Programme on Chemical Safety, Environmental Health Criteria 89: Formaldehyde,
1989.
Published Emergency Response Guidelines
Emergency Response Planning Guideline (ERPG) Values(a)
ERPG-1*
ERPG-2**
ERPG-3***
Listed value
(ppm)
1
10
40
Calculated value
(mg m-3)
1.2
12
48
* Maximum airborne concentration below which it is believed that nearly all individuals could be
exposed for up to 1 hr without experiencing other than mild transient adverse health effects or
perceiving a clearly defined, objectionable odour.
** Maximum airborne concentration below which it is believed that nearly all individuals could be
exposed for up to 1 hr without experiencing or developing irreversible or other serious health effects or
symptoms which could impair an individual's ability to take protective action.
*** Maximum airborne concentration below which it is believed that nearly all individuals could be
exposed for up to 1 hr without experiencing or developing life-threatening health effects.
Interim Acute Exposure Guideline Levels (AEGLs)(b)
AEGL-1†
AEGL-2††
AEGL-3†††
10 min
0.9
14
100
30 min
0.9
14
70
ppm
60 min
0.9
14
56
4 hr
0.9
14
35
8 hr
0.9
14
35
†
The level of the chemical in air at or above which the general population could experience notable
discomfort.
††
The level of the chemical in air at or above which there may be irreversible or other serious longlasting effects or impaired ability to escape.
†††
The level of the chemical in air at or above which the general population could experience lifethreatening health effects or death.
a
American Industrial Hygiene Association (AIHA). 2011 Emergency Response Planning Guideline
Values.
http://www.aiha.org/insideaiha/GuidelineDevelopment/ERPG/Documents/2011erpgweelhandbook_tabl
e-only.pdf (accessed 03/2012).
b
U.S. Environmental Protection Agency. Acute Exposure Guideline Levels,
http://www.epa.gov/oppt/aegl/pubs/chemlist.htm (accessed 03/2012).
Exposure Standards, Guidelines or Regulations
Occupational standards
LTEL(8 hour reference period): 2 ppm (2.5 mg m-3)
WEL(a)
http://www.hse.gov.uk/
STEL(15 min reference period): 2 ppm (2.5 mg m-3)
Public health guidelines
DRINKING
WATER QUALITY GUIDELINE(b)
http://www.who.int/en/
No formal guideline value specified
AIR QUALITY GUIDELINE(c)
http://www.who.int/en/
0.1 mg m-3 as a 30 minute average
SOIL GUIDELINE VALUE AND
HEALTH CRITERIA VALUES
No guideline value specified
WEL – Workplace exposure limit; LTEL - Long-term exposure limit; STEL – Short-term
exposure limit
a
EH40/2005 Workplace Exposure Limits (second edition, published 2011).
http://www.hse.gov.uk/pubns/priced/eh40.pdf (accessed 01/2012)
b
Guidelines for Drinking-Water Quality, Fourth Edition. WHO, Geneva. 2011.
c
Air Quality Guidelines for Europe. World Health Organization Regional Office for Europe,
Copenhagen WHO Regional Publications, European Series, No. 91, Second Edition, 2000.
Health Effects
Major route of exposure(a-b)


Due to its gaseous nature, inhalation is the most likely route of exposure.
Exposure to formaldehyde solutions may occur via ingestion and skin or eye contact.
Immediate Signs or Symptoms of Acute Exposure(b-e) b c







Inhalation of formaldehyde causes irritation of the mucous membranes and
respiratory tract. Sore throat, rhinitis, nasal irritation, bronchospasm and
breathlessness are common
In severe cases, laryngeal and pulmonary oedema, pneumonitis and acute
respiratory distress syndrome may occur.
Ingestion of concentrated formaldehyde solutions can cause burns and ulceration to
the GI tract. Common features are a burning sensation in the mouth and throat, chest
or abdominal pain, nausea, vomiting, diarrhoea and GI haemorrhage. The most
severe damage is found in the stomach; perforation has been reported. Rarely, free
fluid has been demonstrated in the abdomen in the absence of obvious perforation.
Hypotension and shock are common. Restlessness, drowsiness, coma and
convulsions may also occur. Respiratory failure occasionally secondary to acute
respiratory distress syndrome may also complicate severe poisoning. Death from
circulatory collapse may occur in severe cases.
Other clinical features include metabolic acidosis, disseminated intravascular
coagulation, jaundice, proteinuria, albuminuria, haematuria, hyperglycaemia , minor
increase in transaminase activity and methaemoglobinaemia.
Dermal contact with solutions of formaldehyde may produce skin irritation.
Sensitisation caused by dermal contact has been reported frequently. In some
individuals, formaldehyde can react with proteins in the epidermis, producing haptenprotein complexes that are capable of sensitising T lymphocytes so that subsequent
exposures result in allergic contact dermatitis through a type IV hypersensitivity
reaction.
Formaldehyde is irritating to the eyes.
TOXBASE - http://www.toxbase.org (accessed 01/2012)
a
TOXBASE: Formaldehyde, 2011
b
TOXBASE: Formalin and formaldehyde solutions- ingestion, 2011
c
TOXBASE: Formaldehyde – Inhalation, 2011
d
TOXBASE: Formalin and formaldehyde solutions – skin contact, 2011.
e
TOXBASE: Formalin and formaldehyde solutions – eye contact, 2011.
Decontamination and First Aid
Important Notes


Ambulance staff, paramedics and emergency department staff treating chemicallycontaminated casualties should be equipped with Department of Health approved,
gas-tight (Respirex) decontamination suits based on EN466:1995, EN12941:1998
and prEN943-1:2001, where appropriate.
Decontamination should be performed using local protocols in designated areas such
as a decontamination cubicle with adequate ventilation.
Dermal exposure(a)









Remove patient from exposure.
Do NOT apply neutralising chemicals as heat produced during neutralization
reactions may cause thermal burns and increase injury.
Contaminated clothing and any particulate matter adherent to skin should be
removed and the patient washed with copious amounts of water under low pressure
for at least 10-15 minutes, or until pH of skin is normal (pH of the skin is 4.5 – 6
although it may be closer to 7 in children, or after irrigation). The earlier irrigation
begins, the greater the benefit.
Pay special attention to skin folds, fingernails and ears.
Recheck pH of affected areas after a period of 15-20 minutes and repeat irrigation if
abnormal. Burns with strong solutions may require irrigation for several hours or
more.
Once the pH is normal and stabilised, treat as per a thermal injury.
Burns totalling more than 15% of body surface area in adults (>10% in children) will
require standard fluid resuscitation as for thermal burns.
Moderate/severe chemical burns should be reviewed by a burns specialist. Excision
or skin grafting may be required.
Other measures as indicated by the patient's clinical condition
Ocular exposure(b)




Remove contact lenses if present and immediately irrigate the affected eye
thoroughly with water or 0.9% saline for at least 10-15 minutes. Continue until the
conjunctival sac pH is normal (7.5 - 8.0), retest after 20 minutes and use further
irrigation if necessary..
Any particles lodged in the conjunctival recesses should be removed.
Patients with corneal damage or those whose symptoms do not resolve rapidly
should be referred for urgent ophthalmological assessment.
Inhalation(c)




Ensure a clear airway and adequate ventilation.
Give high-flow oxygen through a tight-fitting mask.
Apply other supportive measures as indicated by the patient’s clinical condition.
a
TOXBASE: Skin decontamination – corrosives, 2010.
b
TOXBASE: Chemicals splashed or sprayed into the eyes, 2007.
c
TOXBASE: Formaldehyde – Inhalation, 2011
Ingestion(a)





Ensure a clear airway and adequate ventilation.
There is no role for either gastric lavage or activated charcoal.
Look for evidence of burns in the mouth and throat and watch for features of GI
haemorrhage.
Monitor pulse, blood pressure and urine output.
Apply other supportive measures as indicated by the patient’s clinical condition.
document.
a
TOXBASE: Formalin and formaldehyde solutions- ingestion, 2011
Formaldehyde
Toxicological overview
Key Points
Kinetics and metabolism




Formaldehyde is readily absorbed following inhalation and ingestion, but poorly
absorbed following dermal exposure
Formaldehyde is rapidly metabolised at the initial site of contact into formate prior to
reaching the systemic circulation
Negligible amounts of inhaled or ingested formaldehyde reach the systemic
circulation
It is eliminated either by urinary excretion as formic acid or exhaled as carbon dioxide
Health effects of acute exposure




Acute inhalation exposure to formaldehyde results in irritation and burning of the
mucous membranes of the nose, mouth and upper respiratory tract
Severe inhalation may cause weakness, headache, nausea, vomiting, pneumonia,
dyspnoea, wheezing, coughing, laryngeal and pulmonary oedema, bronchospasm,
respiratory depression, laryngeal spasm, CNS depression, convulsions and coma
Acute ingestion will cause irritation, ulceration, burns and haemorrhage to the
gastrointestinal tract, as well as metabolic acidosis, tachypnoea, jaundice and acute
renal failure
Formaldehyde is corrosive and can cause irritation and burns to the skin and irritation
of the eyes. Ocular exposure may result in permanent vision alterations or blindness
Health effects of chronic exposure



Chronic exposure to formaldehyde causes irritation of the mucous membranes tract
as observed following acute exposure and may be associated with temporarily
decreased lung function
Chronic dermal exposure can lead to skin irritation and may cause skin sensitisation
(allergic contact dermatitis)
Formaldehyde is a human carcinogen
Prepared by J C Wakefield
CHAPD HQ, HPA
2008
Version 1
FORMALDEHYDE – TOXICOLOGICAL OVERVIEW
Toxicological Overview
Summary of Health Effects
Formaldehyde is readily absorbed from the respiratory tract following inhalation, and from the
gastrointestinal tract following ingestion, but is poorly absorbed following dermal exposure [1,
2]. Ingestion of formaldehyde is not a common route of exposure to formaldehyde in humans
and much of the data relating to the adverse effects of oral ingestion are from case reports of
acute poisoning incidents [1].
The predominant effects following an acute inhalation exposure to formaldehyde is irritation
and burning of the mucous membranes of the nose, mouth and upper respiratory tract [2].
Some adverse effects following acute exposure to large amounts of formaldehyde may
include weakness, headache, nausea, vomiting, pneumonia, dyspnoea, wheezing, coughing,
laryngeal and pulmonary oedema, bronchospasm, laryngeal spasm, respiratory depression,
obstructive tracheo-bronchitis, central nervous system depression, convulsions and coma [2,
3]. The onset of pulmonary oedema may be delayed for 24-48 hours post exposure and may
be fatal [3, 4]. Acute ingestion of formaldehyde will lead to irritation and burns of the mouth
and throat and burns and ulceration of the gastrointestinal tract, chest or abdominal pain,
nausea, vomiting, diarrhoea, gastrointestinal haemorrhage and renal failure [2, 5].
Formaldehyde is corrosive and can cause irritation and burns to the skin and irritation of the
eyes [1-3]. Ocular exposure to formaldehyde may result in permanent alterations to vision or
blindness [6].
Repeated or prolonged occupational exposure to formaldehyde causes irritation of the
mucous membranes tract similar to that observed following acute exposure [1]. Occupational
exposure to formaldehyde vapour has been associated with temporary reversible decreases
in lung function [3].
Repeated or prolonged dermal exposure to splashes of solutions containing formaldehyde
can lead to skin irritation and may also cause skin sensitisation (allergic contact dermatitis)
[2].
Formaldehyde is not considered to be a reproductive or developmental toxicant at exposures
below those which result in significant maternal toxicity [7].
The International Agency for Research on Cancer has evaluated that there is sufficient
evidence for the carcinogenicity of formaldehyde both in humans and in experimental
animals. Formaldehyde is therefore considered to be carcinogenic to humans (group 1) [7].
Toxicological overview: Page 2 of 10
Kinetics and metabolism
Formaldehyde is readily absorbed from the respiratory tract following inhalation, and from the
gastrointestinal tract following ingestion, but is poorly absorbed following dermal exposure [1,
2]. Studies involving human volunteers and experimental animals have demonstrated that
inhalation exposure to formaldehyde resulted in only local absorption in the upper respiratory
tract, with any absorbed formaldehyde rapidly undergoing metabolism prior to reaching the
systemic circulation [1].
Formaldehyde is metabolised at the initial site of contact into formate, by formaldehyde
dehydrogenase [1]. Formaldehyde is naturally a metabolic intermediate produced in all cells
during the metabolism of serine, glycine, methionine and choline [1]. Neither formaldehyde or
its metabolites accumulate in any of the body tissues to any appreciable extent. However,
the elimination of formate is slower than its formation from formaldehyde [2]. Formaldehyde
is eliminated mainly by urinary excretion as formic acid or exhaled as carbon dioxide [1-3].
Sources and route of human exposure
The major source of exposure to exogenous formaldehyde is from occupational exposure,
since it is produced and used in large quantities industrially. Formaldehyde is used in the
manufacture of many permanent adhesives such as those used to produce plywood,
fibreboard, particle board and carpet adhesives [1-3]. Small amounts of formaldehyde may
be released into the environment by off-gassing from such materials [2, 3]. Formaldehyde in
solutions of approximately 5% in water is also used as a disinfectant and fumigant in
hospitals [1-3].
Small amounts of formaldehyde occur naturally in the environment and may also be present
in the emissions from the combustion of organic materials such as wood and tobacco smoke,
and automobile emissions [1-3]. However, the amounts of formaldehyde present from such
sources are likely to be smaller than may be found in an occupational setting [2]. In
occupational settings the level of formaldehyde in the air should be controlled to the
occupational exposure standard (2 ppm in the UK) by adequate ventilation, if this cannot be
achieved breathing protection should be used [4]. Adequate personal protective equipment is
also recommended to protect against skin contact from splashes of formaldehyde solutions
[4].
The major routes of occupational exposure to formaldehyde are by inhalation of vapour or by
dermal contact with splashes of formaldehyde solutions. However, ingestion of formaldehyde
is not a significant occupational hazard [1-3].
Health Effects of Acute / Single Exposure
Human Data
General toxicity
Formaldehyde is toxic by inhalation and ingestion. Formaldehyde is also a severe irritant to
the skin, eyes, mouth, nose and upper respiratory tract [1-4].
Inhalation
The predominant effects following an acute inhalation exposure to formaldehyde is irritation
and burning of the mucous membranes of the nose, mouth and upper respiratory tract [2].
Acute inhalation exposure to large amounts of formaldehyde may also give rise to weakness,
headache, nausea, vomiting, pneumonia, dyspnoea, wheezing, coughing, laryngeal and
pulmonary oedema, bronchospasm, laryngeal spasm, respiratory depression, obstructive
tracheo-bronchitis, central nervous system depression, convulsions and coma [2, 3].
Inhalation of significant amounts of formaldehyde may be fatal due to the onset of pulmonary
oedema or respiratory failure [2].
Ingestion
Acute ingestion of solutions of formaldehyde is not likely to be a significant route of
occupational exposure. Much of the data relating to the adverse effects of oral ingestion of
formaldehyde in humans are from case reports of acute poisoning incidents [1]. Acute
ingestion of formaldehyde will lead to irritation and burns of the mouth and throat and burns
and ulceration of the gastrointestinal tract, chest or abdominal pain, nausea, vomiting,
diarrhoea and gastrointestinal haemorrhage [2, 5]. Formaldehyde ingestion may also result in
metabolic acidosis, tachypnoea, jaundice, proteinuria, haematuria and acute renal failure [5].
Dermal / ocular exposure
Exposure to either gaseous formaldehyde or splashes of solutions containing formaldehyde
are corrosive and can cause irritation and burns to the skin and irritation of the eyes [1-3].
Ocular exposure to formaldehyde may result in permanent alterations to vision or blindness
[6].
Delayed effects following an acute exposure
Following an acute inhalation exposure of formaldehyde, the onset of pulmonary oedema
which may be delayed for 24 to 48 hours post-exposure [3, 4].
Animal and In-Vitro Data
General toxicity
The acute toxicity of formaldehyde in experimental animals appears similar to that observed
in humans, with local irritation being the most common adverse effect [1, 2].
Inhalation
The LC50 for formaldehyde in rats following a 4-hour exposure is 578 mg m-3 (471 ppm),
whilst in mice the 4-hour LC50 is 497 mg m-3 (405 ppm) [2]. Mice exposed to formaldehyde by
inhalation at 0.6 mg m-3 (0.5 ppm) developed irritation of the eyes, nose and throat [2].
Severe irritation and damage to the epithelium of the nasal cavity has been observed in rats
exposed to formaldehyde at concentrations above 2-6 ppm (2.5 – 7.4 mg m-3) [1, 3].
Ingestion
The oral LD50 for formaldehyde in rats is 800 mg kg-1 body weight [2]. However, there is little
data available relating to the adverse health effects of formaldehyde in experimental animals
following acute oral exposure [1, 2].
Dermal / Ocular
Solutions of formaldehyde have been shown to produce mild to moderate skin irritation
following a 4-hour application of a 37% solution [6]. Formaldehyde has been shown to be an
eye irritant in rabbits [2].
Health Effects of Chronic / Repeated Exposure
Human Data
Inhalation
Repeated or prolonged inhalation exposure to formaldehyde as may be experienced in
occupational settings causes irritation of the mucous membranes of the eyes, nose, mouth
and upper respiratory tract similar to that observed following acute exposure [1].
Occupational exposure to formaldehyde vapour has been associated with temporary
reversible decreases in lung function [3]. Chronic inhalation of formaldehyde does not lead to
respiratory sensitisation but can cause symptoms of asthma in susceptible individuals due to
respiratory irritation [3].
Dermal / Ocular
Repeated or prolonged dermal exposure to splashes of solutions containing formaldehyde
can lead to skin irritation or allergic contact dermatitis and may also cause skin sensitisation
[2]. Following sensitisation dermal contact with small amounts of formaldehyde will give rise
to outbreaks of dermatitis which may spread from the hand and arms to the body and face
[6].
Genotoxicity
There is some evidence to suggest that formaldehyde may be genotoxic in humans. Studies
of workers occupationally exposed to formaldehyde showed increases in DNA-protein crosslinks compared to non-exposed individuals [1, 7]. Another study of workers exposed to
formaldehyde showed significant increases in chromosomal aberrations and chromosomal
breakage compared to unexposed controls. However, in the same study, no differences were
observed in the incidences of sister chromatid exchange and unscheduled DNA synthesis
and repair [1].
The Committee on Mutagenicity (COM) considered a number of biomonitoring studies of
genotoxicity in workers exposed to formaldehyde in a variety of occupations. They concluded
that there was no convincing evidence regarding direct systemic mutagenic effects of
formaldehyde from the available biomonitoring studies. They suggested that a secondary
mechanism might be involved, with regard to the genotoxic effects documented in peripheral
blood lymphocytes, in the biomonitoring studies reviewed [8].
The COM concluded that there was no reason to consider that direct systemic mutagenicity
would be involved in the mechanism of formaldehyde-induced systemic mutagenicity. For
occupational and environmental exposure to formaldehyde, the pattern of metabolism and
distribution indicates that a threshold level for in vivo systemic mutagenicity is likely [8].
Carcinogenicity
The International Agency for Research on Cancer (IARC) has evaluated that there is
sufficient evidence for the carcinogenicity of formaldehyde in humans, and has therefore
concluded that formaldehyde is carcinogenic to humans (group 1) [7].
Occupational exposure of workers to formaldehyde has been associated with a significant
increase in mortality due to nasopharyngeal cancers compared with the US national
population [7]. The results from the largest and most informative cohort of industrial workers
in the USA, supported by largely positive findings from other studies, provide sufficient
evidence that formaldehyde causes nasopharyngeal cancer in humans. There was only
limited epidemiological evidence that formaldehyde causes sinonasal cancer in humans [7].
There is strong but not sufficient evidence for a causal association between leukaemia and
occupational exposure to formaldehyde. Increased risk for leukaemia has consistently been
observed in studies of professional workers and in 2 of 3 of the most relevant
studies of industrial workers. These findings fall slightly short of being fully persuasive
because of some limitations in the findings from the cohorts of industrial and garment
workers in the USA and because they conflict with the non-positive findings from the British
cohort of industrial workers [7].
Reproductive and developmental toxicity
There have been relatively few studies investigating the reproductive and developmental
toxicity of formaldehyde. One study noted an increased incidence of menstrual disorders,
anaemia, toxaemia and low birth weight of offspring in female workers exposed to ureaformaldehyde [2]. Of these studies there is insufficient evidence to determine whether
formaldehyde causes reproductive toxicity, due to limitations such as small sample sizes, no
information of confounding factors, self-reporting and a lack of information regarding
concurrent exposure to other potentially harmful compounds [2, 3]. Formaldehyde is not
expected to cause reproductive or developmental toxicity at exposures below maternally
toxic doses [7].
Animal and In-Vitro Data
Inhalation
The chronic toxicity of formaldehyde has been investigated in male rats exposed by wholebody inhalation to concentrations up to 15 ppm (18.4 mg m-3) for 6 hours day-1, 5 days week-1
for 6 weeks. At doses above 6 ppm (7.4 mg m-3), a dose dependent increase in lesions of the
nasal passages was observed, in addition to a significant increase in cell proliferation in the
nasal cavity [3]. Mice exposed to formaldehyde by inhalation at concentrations up to 40 ppm
(49.1 mg m3) for 6 hours day-1, 5 days week-1 for 13 weeks displayed a marked reduction in
body weight, laboured breathing, listlessness, hunched posture and loss of coordination at
concentrations of 20 ppm (24.6 mg m-3) and above. In this study, damage to the trachea and
larynx were also noted at 20 and 40 ppm formaldehyde [3].
Ingestion
Male and female Wistar rats exposed to formaldehyde in drinking water for up to 2 years
displayed a significant reduction in body weight compared to the controls at 82 mg kg-1 body
weight day-1 for the males and 109 mg kg-1 body weight day-1 in the females. The body
weight reduction was associated with a decrease in food and water intake, with terminal
weights approximately 10 – 15% lower than the control animals [1, 6]. In this study,
gastrointestinal lesions including papillomatous hyperplasia and hyperkeratosis, chronic
atrophic gastritis, focal ulceration in the forestomach and hyperplasia in the glandular
stomach were first observed at the same concentrations after 53 weeks [1]. An increase in
renal papillary necrosis was also observed in this study in both male and female rats at
82 mg kg-1 and 109 mg kg-1, respectively, which in the female rats was also accompanied by
a relative increase in kidney weight [1].
Dermal
Hairless mice dermally exposed to 0.2 ml of a 10% aqueous solution of formaldehyde,
2 times week-1 for 60 weeks, developed epidermal hyperplasia and some mice developed
cutaneous ulcers [1, 6].
Studies in guinea pigs, using the guinea pig maximisation test and the Beuhler test, and in
mice using the local lymph node assay, have confirmed that repeated dermal exposure to
formaldehyde causes skin sensitisation [1, 6].
Genotoxicity
The potential of formaldehyde to induce genetic mutations has been extensively studied in
vitro in the Ames test using strains of Salmonella typhimurium both with and without
metabolic activation with liver S9 fraction. Both positive and negative results have been
obtained [2, 3, 6].
Formaldehyde has been found to be positive for mutations in many mammalian culture
systems in the absence of metabolic activation. An increase in sister chromatid exchanges
was reported in cultured human lymphocytes treated with formaldehyde [2]. Positive results
have also been obtained for unscheduled DNA synthesis and chromosomal aberrations in
the absence of metabolic activation [2, 3]. These data suggest that formaldehyde does
possess significant direct acting mutagenic potential in vitro.
In-vivo studies in rats and monkeys exposed to formaldehyde by inhalation at 6 ppm (7.4 mg
m-3) have reported positive results for DNA-protein cross-links in the nasal mucosa [3, 7].
Positive results for chromosomal aberrations have also been obtained in lung cells of rats
exposed to 15 ppm (18.4 mg m-3) formaldehyde by inhalation [3]. Studies of the potential for
formaldehyde to induce sister chromatid exchange in the bone marrow of mice exposed by
inhalation have however, proved to be inconclusive. These studies suggest that
formaldehyde has direct acting mutagenic potential in vivo.
The available in-vivo tests for mutagenicity using the well established bone marrow assays
for chromosome aberrations or micronuclei induction, using either the inhalation or the intraperitoneal route were predominantly negative [2, 7, 8]. They also considered the reported
positives for a dominant lethal effect in in-vivo germ cell assays using this endpoint and
concluded that it was unlikely that the effects resulted from a systemic mutagenic effect of
formaldehyde [8].
The mode of action regarding the induction of nasopharyngeal tumours in rats following
inhalation is consistent with formation of formaldehyde DNA protein cross links with a similar
dose-response to the formation of nasal tumours, with consequent marked local effects on
cytotoxicity, cell proliferation and local site of contact mutagenic events being key elements.
The magnitude of the formaldehyde induced local site of contact proliferation was
emphasised [8].
Overall, formaldehyde has been investigated for its genotoxic potential using both in-vitro
and in-vivo studies. Based on these results, formaldehyde is considered to be mutagenic at
the site of contact.
Carcinogenicity
Evidence of the carcinogenicity of formaldehyde was observed in several studies of rats
exposed by inhalation, particularly by the induction of squamous cell carcinomas in the nasal
cavities [7]. Similar studies in hamsters showed no evidence of carcinogenicity, and studies
in mice either showed no effect, or were inadequate to allow evaluation [3, 7]. Studies in rats
exposed to formaldehyde in drinking water have also shown evidence of carcinogenicity. A
study in male rats demonstrated an increase in forestomach papillomas. A further study in
both male and females rats showed an increase in gastrointestinal leiomyosarcomas,
particularly in the females, whilst another study identified an increased incidence in the male
rats of malignant tumours, lymphomas, leukaemias and testicular interstitial-cell adenomas
[7].
Overall, IARC has concluded that there is sufficient evidence for the carcinogenicity of
formaldehyde in experimental animals [7].
Reproductive and developmental toxicity
Studies of the reproductive and developmental toxicity of formaldehyde in rats, mice, rabbits
and dogs following inhalation, ingestion or dermal exposure have not identified any
embryotoxic, fetotoxic or teratogenic effects at doses below those causing significant
maternal toxicity [2, 6, 7]. Therefore formaldehyde is not considered to be a reproductive or
developmental toxicant.
References
[1]
Agency for Toxic Substances and Disease Registry (ATSDR) (1999). Toxicological
Profile for Formaldehyde. US department of Health and Human Services. Atlanta,
US.
[2]
International Programme on Chemical Safety (IPCS) (1989). Formaldehyde.
Environmental Health Criteria 89. WHO. Geneva.
[3]
Canadian Centre for Occupational
Formaldehyde gas, Cheminfo.
[4]
International Programme on Chemical Safety (IPCS) (2004). Formaldehyde.
International Chemical Safety Card: 0275. WHO. Geneva.
[5]
National Poisons Information Service (NPIS) (2002). Formaldehyde. TOXBASE®.
[6]
Canadian Centre for Occupational
Formaldehyde solutions, Cheminfo.
[7]
International Agency for the Research on Cancer (IARC) (2004). Formaldehyde. Vol
88. IARC. Lyon.
[8]
Committee on Mutagenicity (COM) (2007). Formaldehyde: Evidence for Systemic
Mutagenicity. COM/07/S5.
Health
Health
and
and
Safety
Safety
(CCOHS)
(CCOHS)
(2004).
(2004).
document.

Formaldehyde General information Key Points Fire

Transcription

Similar documents

Next Environmental Monitoring

Sealection 500 Superior Performance Flyer

Mobile Double Sided Bookcase

Carbohydrates III

transmittal - Log into PIX (Phipps Information Exchange)

view the PDF - Kerfkore Company

SERVICE BULLETIN RE: Laminate Flooring Formaldehyde

(MSDS) Multani Mitti Clay

FORMALDEHYDE AN UPDATE ON