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: 752
CCOHS Chemical Name: Acetic acid (solutions of 10% or less)

Ethanoic acid
Ethylic acid
Methanecarboxylic acid
Vinegar acid
Acetic acid (non-specific name)
Acide acetique

Chemical Name French: Acide acétique
Chemical Name Spanish: Acido acético
CAS Registry Number: 64-19-7
RTECS Number(s): AF1225000
EU EINECS/ELINCS Number: 200-580-7
Chemical Family: Saturated aliphatic carboxylic acid / saturated aliphatic monocarboxylic acid / alkanoic acid / acetic acid
Molecular Formula: C2-H4-O2
Structural Formula: CH3-C(=O)-OH


Appearance and Odour:
Clear, colourless liquid; odour of vinegar.

Odour Threshold:
0.037-0.15 ppm (detection) (geometric mean odour threshold: 0.074 ppm).(32)

Warning Properties:
GOOD - The TLV is more than 10 times the odour threshold.

Acetic acid is available as the pure liquid or as solutions in water (6- 90%). Virtually pure acetic acid (99.5% or higher) is called glacial acetic acid. Refer to CHEMINFO record 181 for information on acetic acid solutions of greater than 10%, including glacial acetic acid. Acetic acid forms a monohydrate containing about 23% water.(28)

Uses and Occurrences:
Chemical intermediate (e.g. vinyl acetate monomer, cellulose acetate, acetic anhydride, chloroacetic acid, terephthalic acid), used in manufacture of latex emulsion resins, paints, coatings, adhesives, rubber, nylon, fibres, dyes, aspirin and other pharmaceuticals and medicinals, plastics, lacquers, herbicides, solvents, and other chemicals and products; textile dyeing and finishing; laboratory reagent; deliming agent, acidifying and neutralizing agent; food additive or flavorant; constituent of photographic fixing baths, bacteriocide, fungicide.(17,28,29)
Occurs widely in the environment. Occurs naturally in plant and animal tissues and is a normal metabolite in both plants and animals. Occurs naturally in many fruit juices and in the stems and woody parts of plants.(17)


Clear, colourless liquid with the odour of vinegar. Will not burn. May be harmful if inhaled. Vapour is irritating to the respiratory tract. Causes eye irritation.


Effects of Short-Term (Acute) Exposure

Accidental inhalation of high concentrations has produced nose and throat irritation, shortness of breath, cough, wheezing, and reversible lung injury in workers.(2,3)

Skin Contact:
Acetic acid solutions of 10% or less can cause no to mild irritation, based on animal and human information. Application of 10% acetic acid to intact or abraded skin of human volunteers in a 4-hour patch test showed slight irritation.(4)

Eye Contact:
Acetic acid is a severe eye irritant. Even very dilute solutions of acetic acid have caused severe irritation in animal studies.

Acetic acid solutions of 10% or less are probably mildly irritating to the mouth, throat and gastrointestinal tract. Intentional ingestion 100-200 mL of 80-100% acetic acid has caused severe corrosive injury to the gastrointestinal tract and stomach.(5,6)
Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

There are 2 case reports involving workers exposed to acetic acid (concentration not specified) during the production of cellulose acetate. One report describes workers exposed to 60 ppm acetic acid daily, with a one- hour exposure to 100-260 ppm. No evidence of injury was reported, other than slight irritation of the air passages, stomach and skin.(7) Another report describes 5 workers who were exposed to 82 and 265 ppm acetic acid during particular work phases for 7-12 years. Chronic bronchitis (asthmatic-like in 3 cases and emphysema in one) was observed.(8) These brief reports involved a very small number of workers and do not indicate if there were any other potential exposures or if there were any personal pre-disposing factors. Therefore, no conclusions can be drawn.
Another report describes a photographer who developed reversible airways obstruction after long-term exposure to acetic and sulfuric acids in a dark room.(9) No conclusions can be drawn due to the concurrent exposure and lack of exposure information.

SKIN SENSITIZATION: There is one case report of occupational skin sensitization. A worker occupationally exposed to soldering flux which contained acetic acid, among other ingredients, developed contact dermatitis. No history of allergy was recorded. Patch testing showed a positive result for 2% acetic acid.(10) This single case report does not prove that acetic acid is a skin sensitizer. Two other reports of skin sensitization due to acetic acid cannot be evaluated due to lack of information.(11,12)

RESPIRATORY SENSITIZATION: There is one case report of a 58-year old man developing an asthmatic response following occupational exposure to glacial acetic acid. The man had a history of childhood asthma, but remained symptom free from age 11-56 until the current exposure commenced. The asthmatic response was confirmed by pulmonary function testing.(13) This single case report does not prove that acetic acid is a respiratory sensitizer.


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 human information available. The mutagenicity of acetic acid appears to be an effect of pH on the culture media, rather than mutagenic activity of acetic acid itself. There have been no positive reports of mutagenicity, once the effect of pH on the culture media has been controlled.

Toxicologically Synergistic Materials:
Oral administration of 3% acetic acid to male rats for 8 months has increased the incidence of esophageal cancer caused by N-nitrososarcosin ethyl ester (NSEE).(14) Dermal application of acetic acid to female mice has increased the incidence and rate of development of skin carcinomas caused by 7,12-dimethylbenz[a] anthracene.(15)

Potential for Accumulation:
Acetic acid is absorbed from the gastrointestinal tract and through the lungs. Acetic acid is a normal body component and does not accumulate in the body. It is rapidly metabolized by most tissues and excreted, or used in the production of chemicals required for bodily functions.(16)


If symptoms are experienced, remove source of contamination or have victim move to fresh air and obtain medical advice.

Skin Contact:
As quickly as possible, flush with lukewarm, gently flowing water for at lease 5 minutes or until the chemical is removed. Obtain medical advice. Completely decontaminate clothing, shoes and leather goods before re-use.

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 unaffected eye or onto the face. Obtain medical attention immediately.

If irritation or discomfort occur, obtain medical advice. If vomiting occurs naturally, have victim rinse mouth.

First Aid Comments:
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.


Flash Point:
Will not burn (not combustible)

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable

Autoignition (Ignition) Temperature:
Not applicable

Sensitivity to Mechanical Impact:
Not sensitive. Stable material.

Sensitivity to Static Charge:
Will not accumulate static discharge.

Combustion and Thermal Decomposition Products:
Irritant gases, which may include unburned acid and toxic constituents.

Fire Hazard Summary:
The fire properties of acetic acid depend upon the strength of the solution. In concentrated form, its properties approach those of glacial acetic acid which is combustible. In dilute solution, it is nonhazardous.(30) In a fire situation, water may boil off resulting in a more concentrated solution, which may become combustible. Closed containers may rupture violently when heated.

Extinguishing Media:
Dilute acetic acid solutions do not burn. Use fire extinguishing media appropriate to the surrounding fire conditions.

Fire Fighting Instructions:
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. Application should begin as soon as possible and should concentrate on any unwetted portions of the container.
Dilute solutions of acetic acid are only slightly hazardous to health. Firefighters may enter the area if positive pressure self-contained breathing apparatus (MSHA/NIOSH approved or equivalent) and full Bunker Gear is worn.


NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


Molecular Weight: 60.05 (glacial acetic acid)

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

Physical State: Liquid
Melting Point: FREEZING POINT: -0.317 deg C (1 wt.%); -1.576 deg C (5 wt.%); -3.226 deg C (10 wt.%) (31)
Boiling Point: Approximately 100 deg C (approx. 212 deg F)
Relative Density (Specific Gravity): 0.9996 (1 wt.%); 1.005 (5 wt.%); 1.0121 (10 wt.%) at 20 deg C (water = 1) (31)
Solubility in Water: Soluble in all proportions.
Solubility in Other Liquids: Soluble in all proportions in ethanol, acetone, and glycerol.
Coefficient of Oil/Water Distribution (Partition Coefficient): Log P(oct) = -0.31 (16)
pH Value: 2.4 (1 M (approx. 6%)); 2.9 (0.1 M (approx. 0.6%)), 3.4 (0.01 M (approx. 0.06%))
Vapour Density: 2.07 (air = 1) (33)
Vapour Pressure: Not available; 1.52 kPa (11.4 mm Hg) at 20 deg C (glacial acetic acid) (16,33)
Saturation Vapour Concentration: Not available; 1.5% (15000 ppm) at 20 deg C (glacial acetic acid) (calculated)
Evaporation Rate: 0.97 (butyl acetate = 1) (16)
Critical Temperature: Not available

Other Physical Properties:
VISCOSITY-DYNAMIC: 1.02 mPa.s (1.02 centipoises) (1 wt.%); 1.105 mPa.s (5%); 1.21 mPa.s (10%) at 20 deg C.(31)
SURFACE TENSION: 68 mN/m (68 dynes/cm) (1 wt.%); 60.1 mN/m (5 wt.%); 54.6 mN/m (10 wt.%) at 30 deg C.(31)


Normally stable.

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.

STRONG OXIDIZING AGENTS (e.g. chromic acid, hydrogen peroxide, nitric acid, perchloric acid, potassium permanganate, sodium peroxide) - react violently, with risk of fire and explosion.(30,34,35)
STRONG ALKALIS or CAUSTICS (e.g. sodium or potassium hydroxide), or BASES - may react violently.(30,34)
ACETALDEHYDE - polymerization occurs, with evolution of heat.(30,35)
2-AMINOETHANOL, CHLOROSULFONIC ACID, ETHYLENE DIAMINE, ETHYLENEIMINE, OLEUM - mixing in a closed container caused the temperature and pressure to rise.(30)
For other possible reactions which have been reported for more concentrated solutions, refer to CHEMINFO record 181.

Hazardous Decomposition Products:
None reported.

Conditions to Avoid:
Temperatures above 100 deg C (boiling point of water).

Corrosivity to Metals:
There is no specific information available for very dilute solutions of acetic acid. Concentrated acetic acid attacks most common metals, including steel, iron, most stainless steels, copper, bronze and brass, particularly when diluted with water. Aluminum slowly corrodes, forming a layer of aluminum acetate that prevents further corrosion.(28,29,36,37)

Stability and Reactivity Comments:
Attacks many forms of plastics, rubber and coatings. It dissolves synthetic resins and rubber.(36)


LC50 (mouse): 2810 ppm (4-hour exposure); cited as 5620 ppm (1-hour exposure) (17)

LD50 (oral, rat): 3530 mg/kg (concentration not specified) (18)

Eye Irritation:

Application of in excess of a 1% solution produced severe eye injury in rabbits, which included tissue death (scored 10/10).(18) Application of 0.1 mL of 5% reagent grade acetic acid in a modified Draize test produced moderate to severe irritation in rabbits.(19) Application of an unspecified amount of a 10% solution produced severe, permanent injury in rabbits, while a 5% solution produced severe injury which gradually cleared over a period of 14 days.(20, unconfirmed)

Skin Irritation:

Application of 10% acetic acid in a 4-hour patch test using rabbits and guinea pigs showed negligible to very slight irritation.(4) Application of 0.5 mL of 4% acetic acid to guinea pigs produced mild irritation (scored 1.9/4 (intact) and 1.9/4 (abraded)). Similar application to rabbits produced mild irritation to intact skin (scored 1.5/4) and moderate to severe irritation to abraded skin (scored 3.6/4).(21)

Effects of Short-Term (Acute) Exposure:

Reversible upper respiratory tract irritation and reversible effects on respiratory function have been observed in mice and guinea pigs following inhalation of the vapour. Guinea pigs were exposed for 1 hour to 5, 40, 120 or 570 ppm generated from glacial (99.8%) acetic acid. Dose-dependent reversible effects on respiratory function (e.g. increased pulmonary flow resistance and decreased compliance) were observed. Concentrations of 120 and 570 ppm also caused a decrease in respiration rate and minute volume and increased resistance to airflow.(1) Mice exposed to concentrations greater than 1000 ppm experienced reversible irritation of the upper respiratory tract.(17)

Effects of Long-Term (Chronic) Exposure:

Continuous inhalation exposure to a low concentration (2 ppm) has produced slight changes in the blood and slight changes in liver function in male rats.(22)

Oral exposure to 0.5 mL of 3% acetic acid for 8 months has caused increased cell growth (hyperplasia) of the esophagus and forestomach in male rats.(14) Other studies of oral exposure to concentrations of acetic acid less than 10% cannot be evaluated due to limitations of the studies or lack of information necessary for evaluation.(23,24)

The mutagenicity of acetic acid appears to be an effect of pH on the culture media, rather than mutagenic activity of acetic acid itself. There have been no positive reports of mutagenicity, once the effect of pH on the culture media has been controlled.(25,26) One study showed positive results in Eschericheri coli, but the effects of pH were not considered in the evaluation.(27)


Selected Bibliography:
(1) Amdur, M.O. The respiratory response of guinea pigs to the inhalation of acetic acid vapor. Industrial Hygiene Journal. Vol. 22, no. 1 (February, 1961). p. 1-5
(2) Rajan, K.G., et al. Reversible airways obstruction and interstitial pneumonitis due to acetic acid. British Journal of Industrial Medicine. Vol. 46, no. 1 (January, 1989). p. 67-68
(3) Kern, D.G. Outbreak of the reactive airways dysfunction syndrome after a spill of glacial acetic acid. American Review of Respiratory Disease. Vol. 144, no. 5 (November, 1991). p. 1058-1064
(4) Nixon, G.A., et al. Interspecies comparisons of skin irritancy. Toxicology and Applied Pharmacology. Vol. 31 (1975). p. 481-490
(5) Jurim, O., et al. Disseminated intravascular coagulopathy caused by acetic acid ingestion. Acta Haematologica. Vol. 89 (1993). p. 204-205
(6) Hakenbeck, Von H., et al. Vergiftung mit 80%iger Essigsaure. [English summary]. Zeitschrift fur Urologie und Nephrologie. Vol. 77 (1984). p. 311-314
(7) Vigliani, E.C., et al. Experiences of the Clinica del Lavoro with maximum allowable concentrations of industrial poisons. Archiv fuer Gewerbepathologie und Gewerbehygiene. Vol. 13 (1955). p. 528-535. (English translation: Archives of Industrial Health. Vol. 13 (1956). p. 403)
(8) Parmeggiani, L., et al. On the injuries to health caused by acetic acid in the production of cellulose acetate. [English summary]. Medicina del Lavoro. Vol. 45 no. 5 (1954). p. 319-323
(9) Hodgson, M.J., et al. Respiratory disease in a photographer. American Journal of Industrial Medicine. Vol. 9, no. 4 (April, 1986). p. 349-354
(10) Goh, C.L. Occupational dermatitis from soldering flux among workers in the electronics industry. Contact Dermatitis. Vol. 13. no. 1 (1985). p. 85-90
(11) Weil, A.J., et al. Allergic reactivity to simple aliphatic acids in man. Journal of Investigative Dermatology. Vol. 17 (October, 1951). p. 227-231
(12) Vaneckova, J., et al. Hypersensitivity to rubber surgical gloves in healthcare personnel. Contact Dermatitis. Vol. 31, no. 4 (October, 1994). p. 266-268
(13) Kivity, S., et al. Late asthmatic response to inhaled glacial acetic acid. Thorax. Vol. 49, no. 7 (July, 1994). p. 727-728
(14) Alexandrov, V.A., et al. The stimulating effect of acetic acid, alcohol and thermal burn injury on esophagus and forestomach carcinogenesis induced by N-nitrososarcosin ethyl ester in rats. Cancer Letters. Vol. 47 (1989). p. 179-185
(15) Rostein, J.B. et al. Acetic acid, a potent agent of tumor progression in the multistage mouse skin model for chemical carcinogenesis. Cancer Letters. Vol. 42, nos. 1,2 (September/October, 1988). p. 87-90
(16) HSDB record for acetic acid. Last revision date: 96/01/18
(17) Ghiringhelli, L., et al. Pathology due to acetic acid: observations on experimental animals and on men. [English summary]. Medicina del Lavoro. Vol. 48, no. 10 (1957). p. 559-565
(18) Smyth, Jr., H.F., et al. Range-finding toxicity data: list IV. Archives of Industrial Hygiene and Occupational Medicine. Vol. 4 (1951). p. 119-122
(19) Murphy, J.C., et al. Ocular irritancy responses to various pHs of acids and bases with and without irrigation. Toxicology. Vol. 23 (1982). p. 281-291
(20) Acetic acid. Hygienic Guide Series. American Industrial Hygiene Association, June 1978.
(21) Roudabush, R.L., et al. Comparative acute effects of some chemicals on the skin of rabbits and guinea pigs. Toxicology and Applied Pharmacology. Volume 7 (1965). p. 559-565
(22) Takhirov, M.T. Hygienic standards for acetic acid and acetic anhydride in air. Hygiene and Sanitation. Vol. 34, no. 4 (June, 1969). p. 122-125
(23) Joint FAO/WHO Expert Committee on Food Additives. Acetic acid and its potassium and sodium salts. In: Toxicological evaluation of some food additives including anticaking agents, antimicrobials, antioxidants, emulsifiers and thickening agents. WHO Food Additives Series. Number 5. World Health Organization, 1974. p. 31-33
(24) Solmann, T. Studies of chronic intoxications on albino rats. III. Acetic and formic acids. Journal of Pharmacology and Experimental Therapeutics. Vol. 16 (1921). p. 463-474
(25) Sipi, P., et al. Sister-chromatid exchanges induced by vinyl esters and respective carboxylic acids in cultured human lymphocytes. Mutation Research. Vol. 279, no. 2 (16 May, 1992). p. 75-82
(26) Morita, T., et al. Evaluation of clastogenicity of formic acid, acetic acid and lactic acid on cultured mammalian cells. Mutation Research. Vol. 240, no. 3 (March, 1990). p. 195-202
(27) Demerec, M., et al. A survey of chemicals for mutagenic action in E. Coli. The American Naturalist. Vol. LXXXV, no. 821 (March-April, 1951). p. 119-136
(28) Wagner, Jr., F.S. Acetic acid. In: Kirk-Othmer encyclopedia of chemical technology. 4th edition. Volume 1. John Wiley and Sons, 1991. p. 121-139
(29) Aguilo, A, et al. Acetic acid. In: Ullmann's encyclopedia of industrial chemistry. 5th completely revised edition. Volume A 1. VCH Verlagsgesellschaft, 1985. p. 45-64
(30) Fire protection guide to hazardous materials. 13th ed. Edited by A.B. Spencer, et al. National Fire Protection Association, 2002. NFPA 325; NFPA 491
(31) Weast, R.C., ed. Handbook of chemistry and physics. 66th edition. CRC Press, 1985-1986. p. C-47, D-146, D-161, D-221, F-31
(32) Odor thresholds for chemicals with established occupational health standards. American Industrial Hygiene Association, 1989. p. 12, 42
(33) The Sigma-Aldrich library of chemical safety data. Edition II. Volume 1. Sigma-Aldrich Corporation, 1988. p. 13A
(34) NIOSH pocket guide to chemical hazards. National Institute of Occupational Safety and Health, June 1994. p. 2-3
(35) Urben, P.G., ed. Bretherick's handbook of reactive chemical hazards. 5th edition. Volume 1. Butterworth-Heinemann Ltd., 1995. p. 319-320
(36) Emergency action guide for acetic acid. Association of American Railroads, January, 1988
(37) Corrosion data survey: metals section. 6th edition. National Association of Corrosion Engineers, 1985. p. 2-4,5,6 to 3-4,5,6
(38) European Economic Community. Commission Directive 93/72/EEC. September 1, 1993
(39) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(40) Occupational Safety and Health Administration (OSHA). Acetic and Formic Acids in Workplace Atmospheres. In: OSHA Analytical Methods Manual. Revision Date: Oct. 31, 2001. Available at: <>
(41) Occupational Safety and Health Administration (OSHA). Acetic Acid. In: OSHA Analytical Methods Manual. Revision Date: Oct. 31, 2001. Available at: <>
(42) National Institute for Occupational Safety and Health (NIOSH). Acetic Acid. 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: <>

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: 1996-11-28

Revision Indicators:
Bibliography 1998-05-01
Resistance of material 1999-10-01
Emergency overview 2000-08-01
Acute exposure (ingestion) 2000-08-01
First aid (ingestion) 2000-08-01
Bibliography 2003-03-25
Carcinogenicity 2003-07-03
Resistance of materials for PPE 2004-04-05
Bibliography 2004-04-05
ERPG-1 2004-06-30
ERPG-2 2004-06-30
ERPG-3 2004-06-30
Bibliography 2005-03-12
Passive Sampling Devices 2005-03-12
Sampling/analysis 2005-03-12

©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