Acetone.

Acetone is an analyte commonly detected in tests for volatile organic compounds (VOCs). Synonyms for acetone include

* dimethyl ketone,

* 2-propanone, and

* dimethylketal.

Acetone is a manufactured chemical, but it is also found naturally in the environment. It occurs in plants, trees, volcanic gases, and forest fires, and as a by-product of body fat breakdown.

Acetone is a colorless, extremely flammable liquid. Its chemical formula is [CH.sub.3[COCH.sub.3]]. It has a boiling point of 56[degrees]C, a melting point of -95[degrees]C, dissolves easily in water, and is a member of the ketone family

Industrial processes are the main sources of acetone in the environment. Large quantities of acetone are used in the production of rayon and explosives (as a gelatinizing agent). The chemical can be found in plastics, fibers, drugs, lacquer solvents, gum and resin dissolvers, rubber cement, other chemicals, and some cleaning fluids. Acetone is also present in vehicle exhaust, tobacco smoke, and landfill sites.

The National Institute for Occupational Safety and Health (NIOSH) recommends that exposure from workplace air not exceed 250 parts per million (ppm) for a 10-hour workday 40 hours per week. Most concentrations of acetone found in air samples range from 50 to 200 parts per billion by volume (ppbv) (0.05-0.2 ppm). These concentrations are more than 1,000 times lower than the NIOSH-recommended exposure limits. Acetone has been determined by the U.S. EPA to have negligible effect on the ozone and is exempt from some air pollution regulations. For this reason, many industries are starting to use acetone as a substitute compound for other hazardous air pollutants. Concentrations of acetone in the air may be on the rise because of lack of regulation.

Approximately one-half of the total acetone concentration in air will break down after 22 days. Sunlight and other chemicals that may be present encourage degradation. In small doses, acetone will not bind to soil or build up in animals or humans. The human health effects of long-term exposure to this chemical have not been completely evaluated, but acetone is not known to cause cancer.

Prolonged inhalation of moderate-to-high levels of acetone can cause nose, throat, eye, and lung irritation; headaches; lightheadedness; confusion; increased pulse rate; nausea; vomiting; unconsciousness; and possibly coma.

(Source: This material appeared in Precision Analytical Laboratories' Environmental Tech Tip Program, a free program distributed by Precision Analytical Laboratories, Inc.