The following information has been extracted from our CHEMINFO database, which also contains hazard control and regulatory information. [More about...] [Sample Record]

Access the complete CHEMINFO database by contacting CCOHS Client Services.


CHEMINFO Record Number: 595
CCOHS Chemical Name: Methyl formate

Formic acid, methyl ester
Methyl methanoate

Chemical Name French: Formiate de méthyle
Chemical Name Spanish: Formiato de metilo
CAS Registry Number: 107-31-3
UN/NA Number(s): 1243
RTECS Number(s): LQ8925000
EU EINECS/ELINCS Number: 203-481-7
Chemical Family: Aliphatic carboxylic acid ester / saturated aliphatic carboxylic acid ester / saturated aliphatic monocarboxylic acid ester / alkyl alkanoate / formic acid ester / formate / methyl ester
Molecular Formula: C2-H4-O2
Structural Formula: H-C(=O)-O-CH3


Appearance and Odour:
Colourless liquid with a pleasant, ethereal odour.(9,10,11)

Odour Threshold:
2000 ppm (detection); 2800 ppm (recognition) (11)

Warning Properties:
POOR - reliable odour threshold values are greater than 10 times the TLV; olfactory fatigue may occur (smell may not be noticed after short exposures).(7)(5)

May contain small amounts of methanol.

Uses and Occurrences:
Solvent for cellulose acetate; used as a fumigant and larvicide for tobacco, dried fruits and cereals; as an intermediate in organic synthesis (for formamide, dimethylformamide and formic acid); in preparation of antileukemic agents; and as a hardener for phenol esters. It has been identified in cigarette smoke.(4,9,12,13)


Colourless liquid with a pleasant, ethereal odour. EXTREMELY FLAMMABLE LIQUID AND VAPOUR. Vapour is heavier than air and may spread long distances. Distant ignition and flashback are possible. The vapour is irritating to the nose and throat. May cause lung injury -- effects may be delayed. Central nervous system depressant. High vapour concentrations may cause headache, nausea, dizziness, incoordination and confusion. Very high concentrations may cause unconsciousness and death. EYE IRRITANT. Causes severe eye irritation.


Effects of Short-Term (Acute) Exposure

Methyl formate easily forms high vapour concentrations at room temperature, posing a significant inhalation hazard. The vapour can irritate the nose and throat, and cause depression of the central nervous system (CNS) with symptoms such as headache, nausea, vomiting, incoordination, unconsciousness, and death based on animal and limited human information.
Severe exposures may cause a life-threatening accumulation of fluid in the lungs (pulmonary edema), based on animal information. In some cases, the symptoms of pulmonary edema, such as shortness of breath, can be delayed for several hours. There are no reported human cases of pulmonary edema following exposure to methyl formate.
One historical report indicates that gasping and shortness of breath were commonly reported among 15 employees occupationally exposed to mixed vapours of methyl formate and other related esters. Exposure concentrations were not reported. One case of psychological symptoms (euphoria, depression and loss of memory) was also reported.(2,3,4) No irritation or other symptoms were experienced by volunteers exposed to 1500 ppm vapour for one minute.(5)

Skin Contact:
The liquid and high vapour concentrations are expected to cause no to mild skin irritation, based on limited animal information for the vapour and on animal information for a closely related chemical, ethyl formate. There is no human information available.
There is limited information that methyl formate may be absorbed through the skin.(1,4) It is not known if health effects would result from this route of exposure.

Eye Contact:
The liquid is expected to cause moderate to severe irritation, based on comparison to a closely related chemical, ethyl formate, and the fact that methyl formate reacts slowly with water to form corrosive formic acid (1). The degree of irritation will depend on the concentration of methyl formate and the duration of contact. There is only limited animal and no human information available for contact with the liquid.
High vapour concentrations are expected to be irritating, based on animal and limited human information. Irritation and tearing were reported by 10/15 employees exposed to mixed vapours formed by boiling methyl formate and other esters. Vapour concentrations were not reported. Temporary harmful effects on vision, including one case of loss of sight lasting 2 weeks, were reported in this same group of employees.(3) No irritation was experienced by volunteers exposed to 1500 ppm methyl formate vapour for 1 minute.(5)

Methyl formate may irritate the mouth and throat. Ingestion of large doses may cause symptoms of CNS depression including drowsiness, incoordination and vomiting, based on animal information. There is no human information available. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

Repeated or prolonged contact with solvents in general may cause dermatitis (red, itchy, dry skin).


There is no human or animal information available.

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has not assigned a carcinogenicity designation to this chemical.

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
There is no human or animal information available.

Reproductive Toxicity:
There is no human or animal information available.

There is no information available.

Toxicologically Synergistic Materials:
There is no information available.

Potential for Accumulation:
Methyl formate probably does not accumulate in the body. It is probably absorbed through the lungs, digestive tract and the skin, and distributed to the brain, liver and stomach. It is readily hydrolyzed to form methanol and formic acid, with only small amounts remaining unmetabolized. Methanol and formic acid are further metabolized and exhaled as carbon dioxide.(4)


If victim is unconscious or does not respond, take proper precautions to ensure your own safety before attempting rescue, e.g. wear appropriate protective equipment, use the "buddy" system. Remove source of contamination or move victim to fresh air. If breathing has stopped, trained personnel should begin artificial respiration or, if the heart has stopped, cardiopulmonary resuscitation (CPR) immediately. If breathing is difficult, oxygen may be beneficial if administered by a person trained in its use, preferably on a doctor's advice. Immediately transport victim to an emergency care facility or obtain medical attention.

Skin Contact:
As quickly as possible, flush contaminated area with lukewarm, gently flowing water for at least 5 minutes, or until the chemical is removed. If irritation persists, obtain medical attention immediately. Completely decontaminate clothing, shoes and leather goods before re-use or discard.

Eye Contact:
Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 20 minutes or until the chemical is removed, while holding the eyelid(s) open. Take care not to rinse contaminated water into the non-affected eye. Obtain medical attention immediately.

NEVER give anything by mouth if victim is rapidly losing consciousness, or is unconscious or convulsing. Have victim rinse mouth thoroughly with water. DO NOT INDUCE VOMITING. Have victim drink 240 to 300 mL (8 to 10 ozs) of water. If vomiting occurs naturally, have victim rinse mouth and repeat administration of water. Obtain medical attention immediately.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest).
Consult a doctor and/or the nearest Poison Control Centre for all exposures except minor instances of inhalation or skin contact.
Some recommendations in the above sections may be considered medical acts in some jurisdictions. These recommendations should be reviewed with a doctor and appropriate delegation of authority obtained, as required.
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.

Note to Physicians:
May contain small amounts of methanol and can form methanol in the body. Methanol toxicity should be considered when treating a patient exposed to methyl formate.


Flash Point:
-19 deg C (-2 deg F) (closed cup) (13)

Lower Flammable (Explosive) Limit (LFL/LEL):
4.5% (13)

Upper Flammable (Explosive) Limit (UFL/UEL):
23% (13)

Autoignition (Ignition) Temperature:
449 deg C (840 deg F) (13); 456 deg C (853 deg F) (14)

Sensitivity to Mechanical Impact:
Probably not sensitive. Stable material.

Sensitivity to Static Charge:
Will not accumulate static charge, since it has a high electrical conductivity (1.92 X 10(9) pS/m).(15) Vapours in the flammable range may be ignited by a static discharge of sufficient energy.

Combustion and Thermal Decomposition Products:
Formaldehyde may be formed.

Fire Hazard Summary:
Extremely flammable liquid. Material will readily ignite at room temperature. Vapour is heavier than air and may travel a considerable distance to a source of ignition and flash back to a leak or open container. During a fire, irritating/toxic gases may be generated. Can accumulate in confined spaces, resulting in a toxicity and flammability hazard. Closed containers may rupture violently when heated.

Extinguishing Media:
Use water spray, carbon dioxide, dry chemical powder, "alcohol resistant" foam or polymer foam. Water may be ineffective because it will not cool methyl formate below its flash point. Fire fighting foams are the extinguishing agent of choice for most flammable liquid fires.(10)

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or protected location. Approach fire from upwind to avoid toxic decomposition products.
Stop leak before attempting to stop the fire. If the leak cannot be stopped, and if there is no risk to the surrounding area, let the fire burn itself out. If the flames are extinguished without stopping the leak, vapours could form explosive mixtures with air and reignite.
Water can extinguish the fire if used under favourable conditions and when hose streams are applied by experienced firefighters trained in fighting all types of flammable liquid fires. If possible, isolate materials not yet involved in the fire, and move containers from fire area if this can be done without risk, and protect personnel. Otherwise, fire-exposed containers or tanks should be cooled by application of hose streams and this should begin as soon as possible (within the first several minutes) and should concentrate on any unwetted portions of the container. If this is not possible, use unmanned monitor nozzles and immediately evacuate the area.
If a leak or spill has not ignited, use water spray in large quantities to disperse the vapours and to protect personnel attempting to stop a leak. Water spray can be used to dilute spills to nonflammable mixtures and flush spills away from ignition sources. Solid streams of water may be ineffective and spread material.
For a massive fire in a large area, use unmanned hose holder or monitor nozzles; if this is not possible withdraw from fire area and allow fire to burn. Stay away from ends of tanks, but be aware that flying material from ruptured tanks may travel in any direction. Withdraw immediately in case of rising sound from venting safety device or any discolouration of tank due to fire.
Although methyl formate is only slightly hazardous to health, it may form hazardous decomposition products. Do not enter without wearing specialized protective equipment suitable for the situation. Firefighter's normal protective equipment (Bunker Gear) may not provide adequate protection. Chemical resistant clothing (e.g. chemical splash suit) and positive pressure self-contained breathing apparatus (MSHA/NIOSH approved or equivalent) may be necessary.


NFPA - Health: 2 - Intense or continued (but not chronic) exposure could cause temporary incapacitation or possible residual injury.
NFPA - Flammability: 4 - Will rapidly or completely vaporize at atmospheric pressure and normal ambient temperature, or readily disperse in air and burn readily.
NFPA - Instability: 0 - Normally stable, even under fire conditions, and not reactive with water.


Molecular Weight: 60.05

Conversion Factor:
1 ppm = 2.45 mg/m3; 1 mg/m3 = 0.408 ppm at 25 deg C (calculated)

Physical State: Liquid
Melting Point: -100 deg C (-148 deg F) (12,13)
Boiling Point: 32 deg C (89.6 deg F) (12,13)
Relative Density (Specific Gravity): 0.982 at 15 deg C (16); 0.978 at 20 deg C (17) (water = 1)
Solubility in Water: Soluble (30.4 g/100 mL at 20 deg C) (12)
Solubility in Other Liquids: Soluble in all proportions in ethanol and diethyl ether; soluble in methanol.(4,9,16)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Pure methyl formate is probably neutral. It decomposes slowly in water, releasing formic acid.
Viscosity-Dynamic: 0.360 mPa.s (0.360 centipoises) at 15 deg C; 0.319 mPa.s (0.319 centipoises) at 29 deg C (16)
Viscosity-Kinematic: 0.367 mm2/s (0.367 centistokes) at 15 deg C (calculated)
Surface Tension: 25.15 mN/m (25.15 dynes/cm) at 20 deg C; 24.36 mN/m (24.36 dynes/cm) at 25 deg C (calculated) (16)
Vapour Density: 2.07 (air = 1) (12)
Vapour Pressure: 64 kPa (480 mm Hg) at 20 deg C; 93.3 kPa (700 mm Hg) at 30 deg C (12)
Saturation Vapour Concentration: 632000 ppm (63.2%) at 20 deg C; 921000 ppm (92.1%) at 30 deg C (calculated)
Evaporation Rate: Not available
Critical Temperature: 214 deg C (417.2 deg F) (cited as 487.2 deg K) (16)
Critical Pressure: 6000 kPa (59.2 atm) (16)


Stable in the anhydrous state. May slowly decompose (hydrolyze) to methanol and formic acid in the presence of water.(13)

Hazardous Polymerization:
Does not polymerize.

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

OXIDIZING AGENTS (e.g. chlorine, fluorine, perchlorates or peroxides) - reaction can be violent. Increased risk of fire and explosion.(10,15,18)
NITRATES - May explode.(18)
STRONG ACIDS (e.g. sulfuric acid, oleum, and chlorosulfonic acid) or STRONG BASES (sodium or potassium hydroxide or sodium methoxide) - decomposition (hydrolysis) can occur, releasing heat. The reaction may be vigorous or violent.(10,18,19)

Hazardous Decomposition Products:
Methanol and formic acid

Conditions to Avoid:
Flames, sparks, electrostatic discharge, heat and other ignition sources, moisture.

Corrosivity to Metals:
Anhydrous methyl formate is not corrosive to iron, steel, stainless steel, aluminum, copper and nickel and their alloys, and lead. In the presence of water or moisture, methyl formate may decompose slowly to formic acid, which is corrosive to iron, steel, some stainless steels, copper and its alloys and lead.(20)

Stability and Reactivity Comments:
May attack some plastics, rubber and coatings.(15,18)


LD50 (oral, rabbit): 1620 mg/kg (cited as 27 mmol/kg) (6)
LD50 (oral, rat): 475 mg/kg (23, unconfirmed)
LD50 (oral, mouse): 675 mg/kg (23, unconfirmed)

Eye Irritation:

An unpublished report describes methyl formate as a moderate eye irritant.(23) There are insufficient details available to evaluate this report. Squinting was observed in guinea pigs after 2-3 or 3-10 minute exposures to 3500-50000 ppm, but was not observed at 1500 ppm.(5) Eye irritation has also been observed in cats exposed to high vapour concentrations (5916 ppm for 60 minutes and 10200 ppm for 20 minutes).(2)

Skin Irritation:

There is no information available for contact with the liquid. In one study, skin irritation was observed in cats exposed to 9000-10000 ppm vapour for 1-2 hours, however this effect was not observed in other similar studies.(2)

Effects of Short-Term (Acute) Exposure:

Inhalation exposure of guinea pigs to 1500 to 3500 ppm for up to 8 hours has produced upper respiratory tract (nose and throat) irritation. Higher concentrations (10000 ppm) have produced signs of central nervous system (CNS) depression such as incoordination at 2 hours and unconsciousness and death in 2-3 hours. All animals exposed to 25000 ppm died within 72 minutes and animals exposed to 50000 ppm died within 20-30 minutes. Autopsy has shown severe lung injury (fluid accumulation and emphysema).(5) Similar results have been shown in other studies with CNS depression observed in cats exposed to a concentration as low as 5900 ppm for 50 minutes.(2,7,8)

Symptoms of CNS depression (stupor and loss of voluntary movements) were also observed in 50% of rabbits fed 1620 mg/kg (cited as 27 mmol/kg).(6)


Selected Bibliography:
(1) Bisesi, M.S. Esters. In: Patty's industrial hygiene and toxicology. 4th ed. Vol. 2. Toxicology. Part D. Edited by G.D. Clayton, et al. John Wiley and Sons, Inc., 1994. p. 2967-3118
(2) von Oettingen, W.F. The aliphatic acids and their esters: toxicity and potential dangers. A.M.A. Archives of Industrial Health. Vol. 20 (Dec. 1959). p. 81/517-95/531
(3) Grant, W.M., et al. Toxicology of the eye. 4th ed. Charles C. Thomas, 1993. p. 980
(4) Westberg, H., et al. Methyl formate. In: Criteria documents from the Nordic Expert Group, 1989. Edited by G. Heimburger, et al. Arbete och Halsa. Vol. 1989:37. p. 175-201
(5) Schrenk, H.H., et al. Acute response of guinea pigs to vapors of some new commercial organic compounds: XIII. Methyl formate. Public Health Reports. Vol. 51, no. 39 (Sept. 25, 1936). p. 1329-1337
(6) Munch, J.C. Aliphatic alcohols and alkyl esters: narcotic and lethal potencies to tadpoles and to rabbits. Industrial Medicine. Vol. 41, no. 4 (Apr. 1972). p. 31-33
(7) Lehmann, K.B., et. al., ed. Esters: methyl formate. In: Toxicology and hygiene of industrial solvents. The Williams and Wilkins Company, 1943. p. 216-218
(8) Nuckolls, A.H. The report on the comparative life, fire, and explosion hazards of common refrigerants. Miscellaneous Hazard No. 2375. Underwriter's Laboratories, Nov. 13, 1933
(9) HSDB record for methyl formate. Last revision date: 97/03/27
(10) The Sigma-Aldrich library of chemical safety data. Ed. II. Vol. 2. Sigma-Aldrich Corporation, 1988
(11) Odor thresholds for chemicals with established occupational health standards. American Industrial Hygiene Association, 1989. p. 24, 68
(12) Verschueren, K. Handbook of environmental data on organic chemicals. 3rd ed. Van Nostrand Reinhold, 1996. p. 1284-1285
(13) Tau, K.D., et al. Esters, organic. In: Kirk-Othmer encyclopedia of chemical technology. 4th ed. Vol. 9 . John Wiley and Sons, 1994. p. 781-812
(14) Fire protection guide to hazardous materials. 13th ed. Edited by A.B. Spencer, et al. National Fire Protection Association, 2002. NFPA 325; NFPA 49
(15) Chemical safety sheets: working safely with hazardous chemicals. Kluwer Academic Publishers, 1991. p. 599
(16) Dean, J.A. Lange's handbook of chemistry. 14th ed. McGraw-Hill, Inc., 1992. p. 1.254, 5.114, 6.142
(17) Stoye, D., et al. Solvents. In: Ullman's encyclopedia of industrial chemistry. 5th revised ed. Vol. A 24. VCH Verlagsgesellschaft, 1993. p. 448-453, 476-484
(18) Pohanish, R.P., et al. Rapid guide to chemical incompatibilities. Van Nostrand Reinhold, 1997. p. 530
(19) Urben, P.G., ed. Bretherick's handbook of reactive chemical hazards. 5th ed. Vol. 1. Butterworth-Heinemann, Ltd., 1995. p. 320
(20) Corrosion data survey: metals section. 6th ed. National Association of Corrosion Engineers, 1985. p. 82-3 to 83-3
(21) NIOSH pocket guide to chemical hazards. National Institute for Occupational Safety and Health, June 1994
(22) European Communities. Commission Directive 98/98/EC. Dec. 15, 1998
(23) Sharp, R. L. Toxicity and health hazard summary of methyl formate with cover letter dated 021594. Eastman Kodak Co., Apr. 21, 1980. EPA/OTS 8690000093. NTIS/OTS 0556689.

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 1999-02-01

Revision Indicators:
EU Class 2000-04-01
EU Risk 2000-04-01
EU Safety 2000-04-01
Acute exposure (ingestion) 2000-08-01
First aid (ingestion) 2000-08-01
Toxicological info 2003-05-12
Bibliography 2003-05-12
Short-term inhalation 2003-05-12
Short-term eye contact 2003-05-12
Carcinogenicity 2003-05-12
WHMIS detailed classification 2003-05-12
WHMIS proposed classification 2003-05-12
WHMIS health effects 2003-05-12
Emergency overview 2003-05-12
Handling 2003-05-26
Skin protection 2003-05-26
PEL transitional comments 2003-12-19
PEL-TWA final 2003-12-19
PEL-STEL final 2003-12-19

©2007 Canadian  Centre  for  Occupational  Health  &  Safety  E-mail:  Fax: (905) 572-2206  Phone: (905) 572-2981  
Mail:  250  Main  Street  East,  Hamilton  Ontario  L8N  1H6