IPCS INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
Health and Safety Guide No. 105
METHANOL
HEALTH AND SAFETY GUIDE
UNITED NATIONS ENVIRONMENT PROGRAMME
INTERNATIONAL LABOUR ORGANISATION
WORLD HEALTH ORGANIZATION
WORLD HEALTH ORGANIZATION, GENEVA 1997
This is a companion volume to
Environmental Health Criteria 196: Methanol
Published by the World Health Organization for the International
Programme on Chemical Safety (a collaborative programme of the United
Nations Environment Programme, the International Labour Organisation,
and the World Health Organization) and produced within the framework
of the Inter-Organization Programme for the Sound Management of
Chemicals
WORLD HEALTH ORGANIZATION, GENEVA 1997
This report contains the collective views of an international group of
experts and does not necessarily represent the decisions or the stated
policy of the United Nations Environment Programme, the International
Labour Organisation, or the World Health Organization.
WHO Library Cataloguing in Publication Data
Methanol: health and safety guide.
(Health and safety guide ; no. 105)
1.Alcohol, Methyl - toxicity 2.Environmental exposure
I.Series
ISBN 92 4 151105 2 (NLM Classification: QV 83)
ISSN 0259-7268
The World Health Organization welcomes requests for permission to
reproduce or translate its publications, in part or in full.
Applications and enquiries should be addressed to the Office of
Publications, World Health Organization, Geneva, Switzerland, which
will be glad to provide the latest information on any changes made to
the text, plans for new editions, and reprints and translations
already available.
(c) World Health Organization 1997
Publications of the World Health Organization enjoy copyright
protection in accordance with the provisions of Protocol 2 of the
Universal Copyright Convention. All rights reserved.
The designations employed and the presentation of the material in this
publication do not imply the expression of any opinion whatsoever on
the part of the Secretariat of the World Health Organization
concerning the legal status of any country, territory, city or area or
of its authorities, or concerning the delimitation of its frontiers or
boundaries.
The mention of specific companies or of certain manufacturers'
products does not imply that they are endorsed or recommended by the
World Health Organization in preference to others of a similar nature
that are not mentioned. Errors and omissions excepted, the names of
proprietary products are distinguished by initial capital letters.
CONTENTS
INTRODUCTION
1. PRODUCT IDENTITY AND USES
1.1. Identity
1.2. Physical and chemical properties
1.2.1. Physical properties
1.3. Analytical methods
1.4. Production and uses
2. SUMMARY AND EVALUATION
2.1. Human exposure to methanol
2.2. Uptake, metabolism and excretion
2.3. Effects on organisms in the environment
2.4. Effects on laboratory animals and in vitro test systems
2.5. Effects on humans
3. CONCLUSIONS
4. HUMAN HEALTH HAZARDS, PREVENTION AND PROTECTION, EMERGENCY ACTION
4.1. Human health hazards, prevention and protection, first aid
4.2. Information for physicians
4.3. Health surveillance advice
4.4. Explosion and fire hazards
4.4.1. Explosion hazards
4.4.2. Fire hazards
4.4.3. Prevention
4.4.4. Fire-extinguishing agents
4.5. Storage
4.6. Transport
4.7. Spillage and disposal
5. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION
6. SUMMARY OF CHEMICAL SAFETY INFORMATION
7. CURRENT REGULATIONS, GUIDELINES AND STANDARDS
7.1. Exposure limit values
7.2. Labelling, packaging and transport
BIBLIOGRAPHY
INTRODUCTION
The Environmental Health Criteria (EHC) monographs produced by the
International Programme on Chemical Safety include an assessment of
the effects on the environment and on human health of exposure to a
chemical or combination of chemicals, or physical or biological
agents. They also provide guidelines for setting exposure limits.
The purpose of a Health and Safety Guide is to facilitate the
application of these guidelines in national chemical safety
programmes. The first three sections of a Health and Safety Guide
highlight the relevant technical information in the corresponding EHC.
Section 4 includes advice on preventive and protective measures and
emergency action; health workers should be thoroughly familiar with
the medical information to ensure that they can act efficiently in an
emergency. Within the Guide is a Summary of Chemical Safety
Information which should be readily available, and should be clearly
explained, to all who could come into contact with the chemical. The
section on regulatory information has been extracted from the legal
file of the International Register of Potentially Toxic Chemicals
(IRPTC) and from other United Nations sources.
The target readership includes occupational health services, those in
ministries, governmental agencies, industry, and trade unions who are
involved in the safe use of chemicals and the avoidance of
environmental health hazards, and those wanting more information on
this topic. An attempt has been made to use only terms that will be
familiar to the intended user. However, sections 1 and 2 inevitably
contain some technical terms. A bibliography has been included for
readers who require further background information.
Revision of the information in this Guide will take place in due
course, and the eventual aim is to use standardized terminology.
Comments on any difficulties encountered in using the Guide would be
very helpful and should be addressed to:
The Director
International Programme on Chemical Safety
World Health Organization
1211 Geneva 27
Switzerland
THE INFORMATION IN THIS GUIDE
SHOULD BE CONSIDERED AS A
STARTING POINT TO A COMPREHENSIVE
HEALTH AND SAFETY PROGRAMME
1. PRODUCT IDENTITY AND USES
1.1 Identity
Common name: methanol
Chemical formula: CH3OH
Chemical structure:
H
'
H - C - OH
'
H
Relative molecular mass: 32.04
Common synonyms: methyl alcohol; methyl carbinol;
carbinol; wood alcohol; wood spirits;
wood naphtha; Columbian spirits;
Manhattan spirits
Abbreviations: None
CAS registry number: 67-56-1
RTECS number: PC 1400000
United Nations number: 1230
EC number: 603-001-00-X
Conversion factors: 1 ppm = 1.31 mg/m3;
1 mg/m3 = 0.763 ppm at 25°C and
101.4 kPa (760 mmHg)
1.2 Physical and chemical properties
Methanol is a colourless, polar, volatile, flammable liquid with
a mild alcoholic odour when pure. It decomposes on heating producing
carbon monoxide and formaldehyde. Methanol reacts violently with
oxidizing materials such as perchlorates, chromium trioxide, bromine,
sodium hypochlorite, chlorine and hydrogen peroxide resulting in fire
and explosive mixtures.
Methanol mixes well with air, easily forming explosive mixtures.
It is miscible with water, alcohols, esters, ketones and most organic
solvents and forms many azeotropic mixtures.
Methanol for laboratory use is available in various purity grades
for fine chemicals: 1) "synthesis" quality corresponding to normal
commercial methanol; 2) certified analytical quality and 3) extremely
pure quality for semiconductor manufacture. In addition to laboratory
grades, commercial methanol is generally classified according to ASTM
purity grades A and AA. The composition of methanol varies according
to synthesis conditions. In addition to water, typical impurities
include acetone, acetaldehyde, ethanol and higher alcohols, methyl
formate and higher esters.
1.2.1 Physical properties
Melting point (°C) -97.8
Boiling point (°C) 64.7
Refractive index n20 1.3284
Solubility in water miscible
Relative density (d 20/4) 0.7915
Relative vapour density 1.1
(air= 1)
Vapour pressure (kPa at 20°C) 12.3
Ignition temperature (°C) 470
Explosive limits in air lower 5.5
(% by volume) upper 44
Flash-point (°C)
(open cup) 15.60
(closed cup) 12.20
1.3 Analytical methods
For the analysis of production batches of methanol, comparative
ultraviolet spectroscopy has proved to be a convenient rapid test
method. Further tests for establishing the quality of methanol include
measurements of boiling point range, permanganate number, turbidity
colour index and acid number.
More comprehensive tests include water determination according to
the Karl Fischer method and gas chromatographic determination of
by-products of synthesis. The most important standardized test methods
for methanol are: ASTM D1078, boiling range; ASTM D1209, colour index;
ASTM D1353, dry residue; ASTM D1363, permanganate number; ASTM D1364,
water content; ASTM D1612, acetone content; ASTM D1613, acid content;
and ASTM D941, density.
1.4 Production and uses
Modern industrial-scale methanol production is based exclusively
on the catalytic conversion of pressurized synthesis gas (hydrogen,
carbon monoxide and carbon dioxide) in the presence of metallic
heterogenous catalysts. All carbonaceous materials such as coal, coke,
natural gas, petroleum and fractions obtained from petroleum (asphalt,
gasoline and gaseous compounds) can be employed as starting material
for synthesis gas production.
The required synthesis pressure is dependent upon the activity of
the particular metallic catalyst employed with copper-containing zinc
oxide-alumina catalysts, the most effective employed with low pressure
processes (50-100 atm) in modern methanol plants. Methanol is purified
by distillation.
Prior to 1930, the earliest important source of methanol (wood
alcohol) was the dry distillation of wood at about 350°C.
Approximately 70% of the methanol produced worldwide is used in
chemical synthesis. The products, in order of importance, are: methyl
tertiary-butyl ether (MTBE), formaldehyde, acetic acid, methyl
methacrylate and dimethyl terephthalate.
Methanol is widely used as an industrial and laboratory solvent
for extracting, washing, drying and recrystallization.
Methanol is present in a broad variety of commercial and consumer
products, including paints, varnishes, shellacs, antifreeze and
gasoline deicers, windshield washer fluids, cleansing solutions, mixed
solvents in duplicating machines, and hobby glues and adhesives.
Only a small proportion of methanol is currently used for energy
production. There is a potential for its use as an oxygenate for
alternative fuel or in fuel blends with gasolines.
2. SUMMARY AND EVALUATION
2.1 Human exposure to methanol
Methanol occurs naturally. It is a natural constituent in blood,
urine, saliva and expired air. Mean blood methanol levels of about
0.73 mg/litre in unexposed individuals have been reported. A mean
level of 0.25 µg methanol/litre is expired by unexposed humans. The
two most important sources of background body burdens of methanol (and
its metabolite formate) are diet and metabolic processes.
Methanol is available in the diet principally from fresh citrus
fruits and juices, vegetables, fermented beverages and diet foods
(principally soft drinks) containing the artificial sweetener
aspartame (which on hydrolysis yields 10% by weight of the molecule to
free methanol that is available for absorption).
The general population may be exposed to methanol principally
from air emissions from miscellaneous industrial and domestic solvent
use, methanol production, end-product manufacturing and bulk storage
and handling losses. General population exposures through air are
currently typically 10 000 times lower than occupational limits.
Occupational exposure to methanol via inhalation is generally low
but may be greater in less controlled conditions. Accidental or
intentional ingestion of methanol-containing products occurs less
frequently and is associated with high morbidity and mortality.
2.2 Uptake, metabolism and excretion
Methanol is readily absorbed by inhalation, ingestion and dermal
exposure and is rapidly distributed to tissues according to the
distribution of body water. A small amount of methanol is excreted
unchanged by the lungs and kidneys.
Metabolism of methanol occurs in a three-step process initially
involving oxidation to formaldehyde by hepatic alcohol dehydrogenase,
which is a saturable rate-limiting process. In the second step,
formaldehyde is oxidized by aldehyde dehydrogenase to formic acid or
formate depending on the pH. In the third step, formic acid is
detoxified by a folate-dependent pathway to carbon dioxide.
Elimination of methanol from the blood appears to be slow in all
species, especially when compared to ethanol. In humans, urinary
methanol concentrations have been found to be proportional to the
concentration of methanol in blood.
Formate clearance from the blood of exposed primates is at least
50% slower than for rodents.
2.3 Effects on organisms in the environment
Methanol is readily degraded in the environment by photooxidation
and by biodegradation processes. Many genera and strains of
microorganisms are capable of using methanol as a growth substrate.
Methanol is readily degradable under both aerobic and anaerobic
conditions in a broad spectrum of environmental media including fresh
and salt water, sediments and soils, ground water, aquifer material
and industrial wastewater.
Methanol is a normal growth substrate for many soil
microorganisms, which are capable of completely degrading methanol to
carbon dioxide and water.
LC50 values in aquatic organisms range from 1300 to
15 900 mg/litre for invertebrates (48- and 96-h exposures), and
13 000 to 29 000 mg/litre for fish (96-h exposure).
LC50 values in aquatic organisms range from 1300 to
15 900 mg/litre for invertebrates (48-h and 96-h exposures), and
13 000 to 29 000 mg/litre for fish (96-h exposures).
Methanol is of low toxicity to aquatic and terrestrial organisms
and effects due to environmental exposure to methanol are unlikely to
be observed, except in the case of spillage.
2.4 Effects on laboratory animals and in vitro test systems
Methanol has a low acute toxicity to non-primate animals. The
LD50 values after oral exposure in the rat, mouse, rabbit and dog
range from 6200 to 13 000 mg/kg and the MLD value is 2000-7000 mg/kg
for the monkey.
Methanol causes profound species-specific toxicity, dependent on
the extent to which formate accumulates in the body following methanol
exposure. Sensitive primate species develop increased blood formate
concentrations following methanol exposure while resistant rodents,
rabbits and dogs do not.
Exposure of non-primate laboratory mammals to high methanol doses
results in CNS depression. Toxic effects found in methanol-exposed
primates include metabolic acidosis and ocular toxicity, effects not
normally found in methanol-exposed lower animals.
Monkeys exposed by inhalation to up to 6550 mg/m3 (5000 ppm)
methanol 6 h/day, 5 days/week for 4 weeks, showed no treatment-related
effects. Twenty repeated exposures to 6550 mg/m3 failed to elicit
optic effects in exposed monkeys.
The inhalation of methanol by pregnant rodents throughout the
period of embryogenesis induces a wide range of concentration-
dependent teratogenic and embryolethal effects.
Negative findings have been reported in studies investigating
the ability of methanol to produce gene mutations in bacteria
( Salmonella typhimurium and E.coli) and yeast ( Saccharomyces
pombe). It induces chromosomal malsegragation in Aspergillus
nidulans.
Methanol does not induce sister chromatid exchanges in Chinese
hamster cells in vitro but caused significant increases in mutation
frequencies in L5178Y mouse lymphoma cells. Administration by
inhalation does not induce chromosomal damage in mice, but there is
some evidence that oral or intraperitoneal administration does.
There are no adequate studies to assess carcinogenicity.
2.5 Effects on humans
Methanol is irritating to the eyes, skin and respiratory tract.
A broad range of ocular effects have been associated with longer-term
occupational exposure to lower levels of methanol. Acute oral and
inhalation exposures and, to a lesser extent, percutaneous absorption
of high concentrations of methanol have resulted in central nervous
system depression, blindness, coma and death.
Repeated or prolonged contact of methanol with skin may result in
dermatitis. Liquid methanol defats the skin. It is also an effective
extracting solvent and may damage the skin permeability barrier.
Nearly all the information on methanol toxicity in humans relates
to the consequences of acute rather than chronic exposure and the vast
majority of poisonings result from the consumption of adulterated
beverages or methanol-containing products. Although oral ingestion is
the most frequent route of poisoning, in severe and exceptional
conditions inhalation of methanol vapour and percutaneous absorption
of methanolic liquids are also effective in producing acute toxic
syndrome characterized by metabolic acidosis, central nervous system
depression, blindness, coma and death.
The severity of the metabolic acidosis is variable and may not
correlate well with the amount of methanol ingested. The variability
of the toxic dose is a prominent feature in methanol toxicity.
The symptoms of methanol poisoning, which may not appear for 12
to 24 h, include visual disturbances, nausea, abdominal and muscle
pain, dizziness, weakness and disturbances of consciousness ranging
from coma to clonic seizures.
The lethal dose of methanol for humans is not known for certain,
but is reported to range from 0.3 to 1 g/kg. Autopsies from victims
of lethal methanol poisoning reveal retinal and optic nerve
degeneration and gross pathology in the visceral organs, lungs and
central nervous system, involving a variety of oedematous,
haemorrhagic and degenerative changes.
Visual disturbances of several types (blurring, constriction of
the visual field, changes in colour perception and temporary or
permanent blindness) have been reported in workers exposed to methanol
air levels in excess of occupational exposure limits.
No epidemiological data are available to evaluate the
carcinogenicity of methanol for humans. Folate-deficient individuals
might be at greater risk of methanol toxicity compared to normal
individuals. Human populations that are potentially at risk of folate
deficiency include pregnant women, the elderly, alcoholics,
individuals with poor quality diets and individuals on certain
medication.
3. CONCLUSIONS
The general population may be exposed to very low levels of
methanol due to emissions in air from its production, end-uses,
storage and handling, and the broad range of methanol-containing
products.
Occupational exposure may occur during the production of methanol
and its storage and handling, as well as in end-use product synthesis.
Although the individual responses of humans to methanol may vary
considerably, industrial exposures are not considered hazardous if
concentrations are maintained within prescribed occupational exposure
limits.
Methanol occurs naturally and is present in the diet. It can be
absorbed rapidly by the inhalation, oral and dermal routes and
distributed in the body, but it is only slowly metabolized to formate
(which is believed to be the cause of visual damage) and then
excreted. Methanol is rapidly degraded in the environment with no
evidence of bioaccumulation. The available data do not indicate that
there are any significant effects in the environment.
4. HUMAN HEALTH HAZARDS, PREVENTION AND PROTECTION, EMERGENCY ACTION
4.1 Human health hazards, prevention and protection, first aid
Methanol vapour and solutions are irritating to the skin and
eyes. Prolonged or repetitive skin contact can cause dryness, cracking
and dermatitis.
Methanol is well absorbed by the inhalation, oral and
percutaneous routes and can cause metabolic acidosis and damage to the
central nervous system, optic nerve, retina and liver. The onset of
symptoms may be delayed following exposure (see Summary of Chemical
Safety Information, section 6).
4.2 Information for physicians
Full information on the diagnosis and treatment of methanol
poisoning is contained in the IPCS Poisons Information Monograph
No. 335.
Thorough and vigorous washing of the skin with water will
minimize systemic absorption following skin contamination. Gastric
decontamination should be considered if the patient is seen relatively
early (e.g., within one hour after ingestion).
Following ingestion, effects may be delayed and it is important
to keep the patient under observation. The treatment of poisoning is
based upon the use of ethanol as antidote, haemodialysis and
correction of acidosis (by bicarbonate administration). It is
recommended to contact urgently the nearest poisons information
centre.
4.3 Health surveillance advice
Control of exposure by containment and good working conditions
and hygiene is most important.
A complete medical and occupational pre-employment history should
be taken and a physical examination performed with particular
attention to the skin, eyes, liver and kidneys. Pre-existing skin
disease and a history of alcoholism require a decision as to fitness
for employment.
Because the recognized toxic effects of methanol include retinal
toxicity, optic atrophy and blindness, pre-existing eye disease and
folic acid deficiency should be identified and used as a baseline for
future health assessments.
Subsequent medical examination should be on a regular basis, and
should also be performed in the event of excessive exposure, splashes
in the eye or for any employee who develops ocular symptoms while
working with methanol.
4.4 Explosion and fire hazards
4.4.1 Explosion hazards
Methanol vapour/air mixtures are explosive. Violent reactions of
methanol can occur with oxidizing agents (see section 1.2).
4.4.2 Fire hazards
Methanol is highly flammable and burns with an invisible or light
blue flame. Methanol may be ignited by heat, sparks or flames and
vapour may travel to a source of ignition and flash back.
4.4.3 Prevention
There should be no ignition sources such as open flames, sparks
or smoking in the vicinity of methanol storage or use. Contact of
methanol with oxidants should be avoided. Methanol must be used and
stored in cool closed systems with adequate ventilation and explosion-
proof electrical equipment and lighting.
4.4.4 Fire-extinguishing agents
Small fires can be fought with dry chemical, carbon dioxide,
water spray, alcohol-resistant foam or, if these are not available, by
dilution with plenty of water.
Large fires can be attacked with water spray, fog or alcohol-
resistant foam.
Water spray should be used to cool down containers in fire area.
4.5 Storage
Methanol should be stored in clean containers made from either
mild steel, stainless steel, high density polyethylene or vulcanized
natural rubber. Unsuitable container materials include zinc,
aluminium, magnesium, magnesium alloys, lead, tin, titanium,
plasticised PVC, polystyrene or polymethyl-methacrylate. Storage
tanks should be constructed with an internal floating roof and an
inert gas pad to minimize vapour emissions.
Methanol should be stored in well-ventilated areas away from
direct sunlight and moisture. It should not be stored with oxidizing
materials such as perchlorates, chromium trioxide, bromine, sodium
hypochlorite, chlorine or hydrogen peroxide, owing to fire and
explosive dangers.
Because of the flammability of methanol, storage tanks should be
enclosed by a dike and protected by a foam-type (either carbon dioxide
or dry chemical) fire-extinguishing system.
4.6 Transport
All shipping containers (tank cars, tank trucks, barges, drums
and barrels) should be of carbon steel and in a clean and dry
condition prior to loading.
Air pressure should never be used to load or unload methanol.
Pumping is preferred but inert gas should be used when pressure
loading or unloading.
In case of an accident involving tank trucks or transport
carrying drums or barrels of methanol, the vehicle should be
immediately stopped, and all sources of ignition rapidly removed. In
case of spillage or fire, methods advised in sections 4.7 and 4.4,
respectively, should be used.
4.7 Spillage and disposal
Evacuate danger area, collect leaking liquid in sealable
containers, or dike far ahead of liquid spill for later disposal.
Flush spilled liquids with copious amounts of water and prevent direct
access of run-off to water courses.
For relatively small spillages (about 25 litres), the liquid may
be absorbed onto sand or vermiculite and transferred into suitable
containers. The site of the spillage should be washed thoroughly with
water.
Protective wear, appropriate to the degree of spillage, should
be worn, and personnel allowed to enter the hazard area only when
necessary. Extra personal protection can be achieved by using
complete protective clothing, including self-contained breathing
apparatus.
5. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION
Methanol does not pose a significant hazard for aquatic or
terrestrial life, except in the case of a spillage. Contamination of
soil, water and the atmosphere can be avoided by proper methods of
storage, handling, transport and waste disposal.
6. SUMMARY OF CHEMICAL SAFETY INFORMATION
This summary should be easily available to all health workers
concerned with, and users of methanol. It should be displayed at or
near entrances to areas where there is potential exposure to
methanol, and on processing equipment and containers. The summary
should be translated into the appropriate language(s). All persons
potentially exposed to the chemical should also have the
instructions in the summary clearly explained.
The National Occupational Exposure Limit, the address and
telephone number of the nearest Poison Information Centre, and
local trade names should be added to the summary.
SUMMARY OF CHEMICAL SAFETY INFORMATION
METHANOL
CH3OH
PHYSICAL PROPERTIES OTHER CHARACTERISTICS
Relative molecular mass 32.04 Flammable liquid; slight alcoholic odour
Melting point (°C) -97.8 when pure; crude material may have a
Boiling point (°C) (760 mmHg) 64.7 repulsive pungent odour; burns with
Flash point (closed up) (°C) 12.2 non-luminous blue flame; miscible with
Ignition temperature (°C) 470 water, ethanol, ether, benzene, ketones
Relative density (20°C) 0.792 and most other organic solvents
Relative vapour density 1.1
Vapour pressure (kPa at 20°C) 12.3
HAZARDS/SYMPTOMS PREVENTION AND PROTECTION FIRST AID
SKIN: Vapour and solutions are Wear protective gloves and protective clothing Remove contaminated clothing immediately,
irritant; irritation, redness wash contaminated skin thoroughly with
clear running water and refer for medical
attention
EYES: irritation, redness, pain Ensure vapour concentrations are below Rinse eyes with plenty of water for at least
occupational exposure limits; wear chemical 15 min, then obtain medical advice
safety goggles; use face visor when handling
solutions
SUMMARY OF CHEMICAL SAFETY INFORMATION (Con't)
METHANOL
CH3OH
PHYSICAL PROPERTIES OTHER CHARACTERISTICS
INGESTION AND SYSTEMIC Do not eat, drink or smoke during work Do not induce vomiting; obtain medical
ABSORPTION BY OTHER ROUTES: attention immediately; the possibility of
Possibility of delayed CNS, optic alcohol administration should be considered
nerve, retina and liver damage
SPILLAGE STORAGE FIRE AND EXPLOSION
SOLUTIONS: Evacuate danger area, Store in cool, fireproof area separated from
collect leaking liquid in sealable strong oxidants
containers, wash away spilled liquid
with plenty of water
WASTE DISPOSAL LABELLING
Collect in sealable containers United Nations Hazard Class; 3
Subsidiary risks; 6.1
Packing group; 11
7. CURRENT REGULATIONS, GUIDELINES AND STANDARDS
7.1 Exposure limit values
Some exposure limit values are given in the accompanying table.
7.2 Labelling, packaging and transport
UN: UN Hazard Class: 3
UN Subsidiary Risks: 6.1
UN Packing Group: 11
EU: The European Union legislation requires labelling as a
dangerous substance, using the designated symbols.
The following standard risk phrases should be used:
F symbol, T symbol
R: 11-23/25
S: 2-7-16-24
CURRENT REGULATIONS, GUIDELINES AND STANDARDS
Exposure Limit Values
Medium Specification Country/organization Exposure limit description Value Effective date
(mg/m3)
AIR Occupational Australia Time-weighted average (TWA) 260
(skin absorption)
Short-term exposure limit (STEL) 310
(Skin absorption)
Belgium Time-weighted average (TWA) 262
(Skin absorption)
Short-term exposure limit (STEL) 328
(skin absorption)
Czech Time-weighted average (TWA) 100
Republic Short-term exposure limit (STEL) 500
Denmark Time-weighted average (TWA) 260 1988
(skin absorption)
Finland Time-weighted average (TWA) 260
(skin absorption)
Short-term exposure limit (STEL) 325
France Time-weighted average (TWA) 260 1982-1989
Short-term exposure limit (STEL) 1300
Germany Time-weighted average (TWA) 260 1990
(skin absorption)
CURRENT REGULATIONS, GUIDELINES AND STANDARDS (Con't)
Exposure Limit Values
Medium Specification Country/organization Exposure limit description Value Effective date
(mg/m3)
Hungary Time-weighted average (TWA) 50
(skin absorption)
Short-term exposure limit (STEL) 100
(skin absorption)
Ireland Time-weighted average (TWA) 262
(skin absorption)
Short-term exposure limit (STEL) 328
(skin absorption)
Italy Time-weighted average limit (STEL) 262
(skin absorption)
Short-term exposure limit (STEL) 328
(skin absorption)
Japan Time-weighted average (TWA) 260
(skin absorption)
Luxembourg Time-weighted average (TWA) 262
(skin absorption)
Short-term exposure limit (STEL) 328
(skin absorption)
Netherlands Time-weighted average (TWA) 260 1989
CURRENT REGULATIONS, GUIDELINES AND STANDARDS (Con't)
Exposure Limit Values
Medium Specification Country/organization Exposure limit description Value Effective date
(mg/m3)
Poland Time-weighted average (TWA) 100
Portugal Time-weighted average (TWA) 262
(skin absorption)
Short-term exposure limit (STEL) 328
(skin absorption)
Spain Time-weighted average (TWA) 262
(skin absorption)
Short-term exposure limit (STEL) 328
(skin absorption)
Sweden Time-weighted average (TWA) 250
(skin absorption)
Short-term exposure limit (STEL) 350
(skin absorption)
Switzerland Time-weighted average (TWA) 260
(skin absorption)
Short-term exposure limit (STEL)
(skin absorption) 520
United Time-weighted average (TWA) 260 1990
Kingdom (skin absorption)
Short-term exposure limit (STEL) 310
(skin absorption)
CURRENT REGULATIONS, GUIDELINES AND STANDARDS (Con't)
Exposure Limit Values
Medium Specification Country/organization Exposure limit description Value Effective date
(mg/m3)
USA Time-weighted average (TWA) 262 1989-
(ACGIH) (skin absorption) 1990
Short-term exposure limit (STEL) 328
(skin absorption)
USA Time-weighted average (TWA) 260
(NIOSH/OSHA) (skin absorption)
Short-term exposure limit (STEL) 310
(skin absorption)
Former Time-weighted average (TWA)
USSR (skin absorption)
Short-term exposure limit (STEL) 5
(skin absorption)
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