Any locality found to be in violation of one or more National Ambient Air Quality Standards set by the Environmental Protection Agency (EPA) under the provisions of the Clean Air Act. However, a nonattainment area for one standard may be an attainment area for a different standard. The seven criteria pollutants for which standards were established in 1970 under the Clean Air Act are carbon monoxide, lead, nitrogen dioxide, ozone (a key ingredient in smog), particulate matter, sulfur dioxide, and hydrocarbons. Violation of National Ambient Air Quality Standards for one of the seven criteria pollutants can have a variety of consequences for an area, including restrictions on permits for new stationary sources of pollution (or significant modifications to existing ones), mandatory institution of vehicle emissions inspection programs, or loss of federal funding (including funding unrelated to pollution problems).

See Also

Automobile Emissions