Acetic acid

(Ethanoic acid)

CAS 64-19-7





Physical Properties

Colorless liquid

bp 118 °C, mp 17 °C

Miscible in water (100 g/100 mL)



Strong, pungent, vinegar-like odor detectable at 0.2 to 1.0 ppm

Vapor Density

2.1 (air = 1.0)


Vapor Pressure

11 mmHg at 20 °C


Flash Point

39 °C


Autoignition Temperature

426 °C


Toxicity Data

LD50 oral (rat)

3310 mg/kg


LD50 skin (rabbit)

1060 mg/kg


LC50 inhal (mice)

5620 ppm (1 h)



10 ppm (25 mg/m3)



10 ppm (25 mg/m3)



15 ppm (37 mg/m3)

Major Hazards

Corrosive to the skin and eyes; vapor or mist is very irritating and can be destructive to the eyes, mucous membranes, and respiratory system; ingestion causes internal irritation and severe injury.


The acute toxicity of acetic acid is low. The immediate toxic effects of acetic acid are due to its corrosive action and dehydration of tissues with which it comes in contact. A 10% aqueous solution of acetic acid produced mild or no irritation on guinea pig skin. At 25 to 50%, generally severe irritation results. In the eye, a 4 to 10% solution will produce immediate pain and sometimes injury to the cornea. Acetic acid solutions of 80% or greater concentration can cause serious burns of the skin and eyes. Acetic acid is slightly toxic by inhalation; exposure to 50 ppm is extremely irritating to the eyes, nose, and throat.

Acetic acid has not been found to be carcinogenic or to show reproductive or developmental toxicity in humans.

Flammability and Explosibility

Acetic acid is a combustible substance (NFPA rating = 2). Heating can release vapors that can be ignited. Vapors or gases may travel considerable distances to ignition source

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