Association of American Railroads

Angstrom (1E-10 meters)

Atomic Absorption: Refers to instrument for metals analysis.

Attainment Area (CAA)

Acceptable Ambient Concentration

Association of American Pesticide Control Officials, Inc.

Ambient Air Quality Standards (CAA)

Penetration of a substance into the body of another.

Asbestos Containing Building Materials

Actual Cubic Feet per Minute of gas or air flowing at existing temperature and pressure.

American Conference of Governmental & Industrial Hygienists

A hydrogen containing compound that reacts with water to produce hydrogen ions (H+) with a pH of less than 7.0.

Acid rain is a form of air pollution produced when acid chemicals are incorporated into rain, snow, fog or mist. The "acid" in acid rain comes from sulfur oxides and nitrogen oxides, products of burning coal and other fuels and from certain industrial processes. The sulfur oxides and nitrogen oxides are related to two strong acids: sulfuric acid and nitric acid. When sulfur dioxide and nitrogen oxides are released into the air and are blown into areas where the weather is et, the acids can fall to the Earth in the rain, snow, fog or mist. In areas where the weather is dry, the acid chemicals may become incorporated into dusts or smokes. Acid rain can damage the environment, human health and property.

Alternative Concentration Limit (40 CFR Part 403): General pretreatment regulations for existing and new sources of pollution (CWA).

Asbestos Containing Materials: Materials which contain greater than one percent asbestos.

American Chemical Society

An unanticipated grave natural disaster or other natural phenomenon (such as a tornado, earthquake, etc.), in which the effects of which could not have been prevented or avoided by the exercise of due care or foresight.

An adverse effect on humans or animals, after a single significant exposure (e.g.) cyanide gas.

Any EPA-RCRA hazardous waste beginning with the letter "P" (40 CFR 261.33 (e)) that by definition, is a commercial chemical product (non-process waste) and an off-specification commercial chemical product with only one active ingredient or any of the following "F" waste codes: F020, F021, F022, F023, F026, (40CFR 261.31).

A legal document signed by either a state or federal agency directing an individual, business or entity to take corrective action or refrain form an activity.