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SECTION 1. CHEMICAL IDENTIFICATION

CHEMINFO Record Number: 427
CCOHS Chemical Name: Methyl acetate

Synonyms:
Acetic acid, methyl ester
Methyl acetic ester
Methyl ethanoate
Acetate de methyle

Chemical Name French: Acétate de méthyle
Chemical Name Spanish: Acetato de metilo
Acido acético, éster metílico
CAS Registry Number: 79-20-9
UN/NA Number(s): 1231
RTECS Number(s): AI9100000
EU EINECS/ELINCS Number: 201-185-2
Chemical Family: Aliphatic carboxylic acid ester / saturated aliphatic carboxylic acid ester / saturated aliphatic monocarboxylic acid ester / alkyl alkanoate / acetic acid ester / acetate / methyl ester
Molecular Formula: C3-H6-O2
Structural Formula: CH3-C(=O)-O-CH3

SECTION 2. DESCRIPTION

Appearance and Odour:
Colourless, volatile liquid; pleasant, fruity odour (1,15)

Odour Threshold:
180 ppm (detection); 300 ppm (recognition) (16)

Warning Properties:
POOR - odour threshold is about the same magnitude as the TLV.

Composition/Purity:
Available commercially in pure form (in different grades depending on impurities) and as an 80:20 (methyl acetate:methanol) formulation. May contain small amounts (up to 0.1%) of acetic acid.(1)

Uses and Occurrences:
Widely used as a solvent for cellulose nitrate, cellulose acetate, lacquers, paint removers, resins and oils; in the manufacture of artificial leather; as a flavouring agent and odourant; chemical intermediate; raw material for production of acetic anhydride; catalyst for biodegradation of organic materials.(1,2) Methyl acetate occurs naturally in foods, mainly fruits.(3,4)


SECTION 3. HAZARDS IDENTIFICATION

EMERGENCY OVERVIEW:
Colourless, volatile liquid with a pleasant, fruity odour. EXTREMELY FLAMMABLE LIQUID AND VAPOUR. Vapour is heavier than air and may spread long distances. Distant ignition and flashback are possible. Harmful if swallowed. Eye irritant. Mild central nervous system depression. High vapour concentrations may cause headache, nausea, dizziness, incoordination and confusion.



POTENTIAL HEALTH EFFECTS

Effects of Short-Term (Acute) Exposure

Inhalation:
The vapour can probably irritate the nose and throat. Exposure to 4050 ppm for a short time was the lowest irritating level in humans. Exposure to 10000 ppm produced persistent irritation.(3) No further details are available.
Based on animal information, severe exposures can probably produce signs of central nervous system depression such as shortness of breath, headache, drowsiness and dizziness.

Skin Contact:
There is no human information available. Based on animal data, the liquid is probably a mild irritant.
Based on a dermal LD50, methyl acetate can be absorbed through the skin but is not expected to be toxic by this route of exposure.

Eye Contact:
There is no human information available. Animal evidence indicates that the liquid would cause moderate to severe irritation. Based on animal information, the vapour is probably irritating at high concentrations.(3)
If ingested, methyl acetate may form methanol in the body, which can cause severe damage to vision. There is one case report of eye damage following ingestion of methyl acetate.(5)

Ingestion:
Methyl acetate can probably irritate the mouth and throat. One drop of methyl acetate placed on the human tongue produced a burning sensation, followed by reddening and swelling.(4) Ingestion of small quantities may cause shortness of breath, headache, drowsiness and dizziness; more severe exposures may lead to acidosis, vision impairment and possibly death.(3,5,6).
These severe effects may be caused by methanol and acetic acid which are formed when methyl acetate is broken down (hydrolyzed) in the body. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

SKIN: Methyl acetate can remove natural oils from the skin, resulting in dryness, redness and itching (dermatitis).(6) Sensitization was not reported in 25 volunteers following maximization testing.(4)

No other effects of chronic exposure to methyl acetate have been reported. Because methyl acetate is metabolized (broken down) to methanol in the body, effects similar to those of methanol (CHEMINFO 23) might occur.

Carcinogenicity:

No human or animal information available. Probably not carcinogenic. The metabolites of methyl acetate, methanol and acetic acid, have not been shown to be carcinogenic.

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:
No human or animal information is available.

Reproductive Toxicity:
No human or animal information is available.

Mutagenicity:
No human or animal information is available. Methyl acetate was not mutagenic in one in vitro test with bacteria, but the vapour was mutagenic to yeast.(7,8)

Toxicologically Synergistic Materials:
No information is available.

Potential for Accumulation:
Does not accumulate. Methyl acetate is readily absorbed through the lungs and gastrointestinal tract. It is partly excreted in the expired air and in the urine. It has been shown in humans that methyl acetate is hydrolyzed in the body to acetic acid, which is naturally formed in the body, and methanol, which is excreted in urine.(1,3)


SECTION 4. FIRST AID MEASURES

Inhalation:
This chemical is extremely flammable. Take proper precautions (e.g. remove any sources of ignition). If the 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. Obtain medical attention immediately.

Skin Contact:
As quickly as possible, flush with lukewarm, gently flowing water for at least 5 minutes or until the chemical is removed. Obtain medical advice.

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 or onto the face. Obtain medical attention immediately.

Ingestion:
NEVER give anything by mouth if victim is rapidly losing consciousness, is unconscious or convulsing. DO NOT INDUCE VOMITING. Have victim drink 240 to 300 mL (8 to 10 oz.) of water to dilute material in the stomach. If vomiting occurs naturally, rinse mouth and repeat administration of water. If breathing has stopped, trained personnel should begin artificial respiration or, if the heart has stopped, cardiopulmonary resuscitation (CPR) immediately. 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.
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.



SECTION 5. FIRE FIGHTING MEASURES

Flash Point:
-10 deg C (14 deg F) (closed cup) (2)

Lower Flammable (Explosive) Limit (LFL/LEL):
3.1% (2)

Upper Flammable (Explosive) Limit (UFL/UEL):
16% (2)

Autoignition (Ignition) Temperature:
454 deg C (850 deg F) (2)

Sensitivity to Mechanical Impact:
Not sensitive, since it is a stable compound.

Sensitivity to Static Charge:
Probably will not accumulate static charge, since it has a high electrical conductivity (3.4 x 10(8) pS/m).(13) Vapours in the flammable range may be ignited by a static discharge of sufficient energy.

Fire Hazard Summary:
Extremely flammable. 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. Concentrated solutions in water may be flammable. Closed containers may rupture violently when heated.

Extinguishing Media:
Carbon dioxide, dry chemical powder, alcohol foam, polymer foam. Water may be ineffective because it will not cool methyl acetate below its flash point. Fire fighting foams are the extinguishing agent of choice for most flammable liquid fires.(14)

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or protected location. Approach fire from upwind to avoid hazardous vapours and 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.
Isolate materials not yet involved in the fire and protect personnel. Move containers from fire area if this can be done without risk. 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, to protect personnel attempting to stop a leak. Water spray can be used to dilute spills to nonflammable mixtures and to flush spills away from ignition sources. Solid streams of water may be ineffective and spread material. For a massive fire in a large area,and allow fire to burn. Stay away from ends of tanks. Withdraw immediately in case of rising sound from venting safety device or any discolouration of tank due to fire.
Firefighters may enter the area if positive pressure self-contained breathing apparatus (MSHA/NIOSH approved or equivalent) and full Bunker Gear is worn.



NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) HAZARD IDENTIFICATION

NFPA - Health: 2 - Intense or continued (but not chronic) exposure could cause temporary incapacitation or possible residual injury.
NFPA - Flammability: 3 - Liquids and solids that can be ignited under almost all ambient temperature conditions.
NFPA - Instability: 0 - Normally stable, even under fire conditions, and not reactive with water.

SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES

Molecular Weight: 74.08

Conversion Factor:
1 ppm = 3.02 mg/m3; 1 mg/m3 = 0.33 ppm at 25 deg C (calculated)

Physical State: Liquid
Melting Point: -98.1 deg C (-144.6 deg F) (1,3)
Boiling Point: 56.9 deg C (134.4 deg F) (3,8)
Relative Density (Specific Gravity): 0.933 at 20 deg C (water = 1) (1,2)
Solubility in Water: Very soluble (24.5 g/100 g at 20 deg C) (8)
Solubility in Other Liquids: Soluble in all proportions in ethyl alcohol and diethyl ether; soluble in acetone, benzene and chloroform.(1)
Coefficient of Oil/Water Distribution (Partition Coefficient): Log Poct = 0.18 (17)
pH Value: Can form acetic acid in the presence of water, producing some acidity.
Vapour Density: 2.55 (3,14); 2.8 (1) (air = 1)
Vapour Pressure: 23.1 kPa (173 mm Hg) at 20 deg C (8,14)
Saturation Vapour Concentration: 227700 ppm (22.77%) at 20 deg C (calculated)
Evaporation Rate: 11.8 (butyl acetate = 1) (6)
Critical Temperature: 233.7 deg C (452.7 deg F) (1)

Other Physical Properties:
VISCOSITY-DYNAMIC: 0.381 mPa.s (0.381 centipoises) at 20 deg C (1)
SURFACE TENSION: 24 mN/m (24 dynes/cm) at 20 deg C (1)
CRITICAL PRESSURE: 4590 kPa (45.3 atm) (1)


SECTION 10. STABILITY AND REACTIVITY

Stability:
Stable in the anhydrous state. In the presence of water, methyl acetate may slowly hydrolyze to methanol and acetic acid.(2,15)

Hazardous Polymerization:
Does not occur

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. nitrates, perchlorates, peroxides) - increased risk of fire and explosion.(14,15)
STRONG ACIDS (e.g. sulfuric acid, oleum, and chlorosulfonic acid), STRONG BASES - decomposition (hydrolysis) can occur. Reaction may be vigorous.(14,15)
POTASSIUM TERT-BUTOXIDE - contact with methyl acetate vapour may cause ignition.

Hazardous Decomposition Products:
Methanol, acetic acid

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

Corrosivity to Metals:
Probably not corrosive to metals. The related esters, methyl formate and ethyl acetate are not corrosive to iron, steel, aluminum, copper and nickel and their alloys.(18)

Stability and Reactivity Comments:
Can attack some plastics.(2)


SECTION 11. TOXICOLOGICAL INFORMATION

LC50 (rat): 16000-32000 ppm (4-hour exposure) (9)
LCLO (mouse): 11300 ppm (4-hour exposure); cited as 34 g/m3 (4-hour exposure) (7)

LD50 (oral, rat): greater than 5000 mg/kg (4, unconfirmed)
LD50 (oral, rabbit): 3700 mg/kg (cited as 50 millimols/kg) (10)

LD50 (skin, rabbit): greater than 5000 mg/kg (4)

Eye Irritation:

Application of 100 mg in a standard Draize test produced moderate irritation in rabbits.(7; unconfirmed) Application of 0.005 mL produced severe injury to the corneas of rabbits.(9)

Skin Irritation:

In two studies, application of 500 mg or 0.01 mL produced mild irritation in rabbits in standard Draize tests.(4,9) In another study, application of 20 mg produced moderate irritation in rabbits in a standard Draize test.(7, unconfirmed)

Effects of Short-Term (Acute) Exposure:

Inhalation:
Cats and mice exposed to 18500 ppm or less for short periods (up to 6 hours) experienced eye irritation, difficulty in breathing and central nervous system depression. Exposures up to 55440 ppm for 10-20 minutes (mice) and 53790 ppm for 14-18 minutes (cats) caused fluid accumulation in the lungs and deaths. No effects were noted in mice exposed to 5000 ppm for 20 minutes. While, similar exposure produced eye irritation and salivation in cats.(3,11) Cats exposed to 6600 ppm, 6 hours/day for 7 days showed eye irritation, central nervous system depression, weight loss and some minor effects. Four of 5 cats survived and recovered slowly.(11)


SECTION 16. OTHER INFORMATION

Selected Bibliography:
(1) HSDB record for methyl acetate. Date of last update: 9505
(2) Tau, K.D., et al. Esters, organic. In: Kirk-Othmer encyclopedia of chemical technology. 4th Edition. Vol. 9. John Wiley and Sons, 1994. p. 781-812
(3) Bisesi, M.S. Esters. In: Patty's Industrial Hygiene and Toxicology. 4th edition. Volume II. Toxicology. Part D. John Wiley & Sons, Inc., 1994. p. 2967-2971, 2976-2981
(4) Opdyke, D.L. Monographs on fragrance raw materials: methyl acetate. Food and Cosmetics Toxicology. Vol. 17 (Supplement - Special Issue V) (1979). p. 859-861
(5) Grant W.M. Toxicology of the eye. 4th edition. Charles Thomas, 1993. p. 962
(6) NIOSH/OSHA. Occupational health guideline for methyl acetate. U.S. Department of Health and Human Services, September, 1978. p. 1-5
(7) RTECS record for methyl acetate. Date of last update: 9504.
(8) Methyl acetate. In: Documentation of the threshold limit values and biological exposure indices. 6th edition. American Conference of Governmental Industrial Hygienists, 1992. p. 927-928
(9) Smyth, Jr., H.F., et al. Range-finding toxicity data: list VI. American Industrial Hygiene Association Journal. Vol. 23 (1962). p. 95-107
(10) Munch, J.C. Aliphatic alcohols and alkyl esters. Narcotic and lethal potencies to tadpoles and to rabbits. IMIS: The International Journal of Industrial Medicine and Surgery. Vol. 41, no. 4 (April, 1972). P. 31-33
(11) von Oettingen, W.F. The aliphatic acids and their esters: toxicity and potential dangers. A.M.A. Archives of Industrial Health. Vol. 21. (January, 1960). p. 28-65
(12) Fire protection guide to hazardous materials. 13th ed. Edited by A.B. Spencer, et al. National Fire Protection Association, 2002. NFPA 325
(13) Chemical safety sheets: working safely with hazardous chemicals. Kluwer Academic Publishers, 1991. p. 571
(14) The Sigma-Aldrich library of chemical safety data. Edition II. Vol. 2. Sigma-Aldrich Corporation, 1988. p. 2278B
(15) NIOSH pocket guide to chemical hazards. National Institute for Occupational Safety and Health, June, 1994. p. 196-197
(16) Odor thresholds for chemicals with established occupational health standards. American Industrial Hygiene Association, 1989. p. 22, 65
(17) Leo, A., et al. Partition coefficients and their uses. Chemical Reviews. Vol. 71, no. 6 (December. 1971). p. 560
(18) Corrosion data survey: metals section. 6th edition. National Association of Corrosion Engineers, 1985. p. 54-55, 82-83
(19) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(20) European Communities. Commission Directive 98/98/EC. December 15, 1998
(21) Occupational Safety and Health Administration (OSHA). Organic Vapors. In: OSHA Analytical Methods Manual. Revision Date: Oct. 31, 2001. Available at: <www.osha-slc.gov/dts/sltc/methods/toc.html>
(22) National Institute for Occupational Safety and Health (NIOSH). Methyl Acetate. In: NIOSH Manual of Analytical Methods (NMAM(R)). 4th ed. Edited by M.E. Cassinelli, et al. DHHS (NIOSH) Publication 94-113. Aug. 1994. Available at: <www.cdc.gov/niosh/nmam/nmammenu.html>

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: 1995-11-29

Revision Indicators:
Sampling 1996-03-01
EU number 1996-03-01
Respiratory guidelines 1995-03-01
US transport 1998-03-01
Resistance of materials 1998-06-01
EU Class 2000-04-01
EU Risk 2000-04-01
EU Safety 2000-04-01
EU Comments 2000-04-01
Bibliography 2000-04-01
Bibliography 2003-04-15
NFPA (health) 2003-04-15
PEL transitional comments 2003-11-18
PEL-TWA final 2003-11-18
PEL-STEL final 2003-11-18
PEL transitional comments 2003-11-18
TLV basis 2004-01-04
Resistance of materials for PPE 2004-03-31
Bibliography 2005-03-20
Passive Sampling Devices 2005-03-20
Sampling/analysis 2005-03-20



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