An announcement issued when the following day is predicted to be a public health risk due to excessive air pollution. Air Pollution Watch days are intended to encourage citizens to reduce ozone producing behaviors to help the region avoid ozone exceedance target levels on that day. An Air Pollution Watch is issued via e-mail from the TCEQ's Au [..]

An announcement issued when actual air pollution measurements reach levels deemed to be unhealthy by the Environmental Protection Agency. Air Pollution Warnings are issued via e-mail from the TCEQ's Austin headquarters to local authorities, news organizations and interested citizens within approximately 30 minutes after ozone measurements reac [..]

A fuel that can replace ordinary gasoline. Alternative fuels may have desirable energy efficiency and pollution reduction features. Alternative fuels include compressed natural gas (CNG), alcohols, liquefied petroleum gas (LPG), and electricity.

Outdoor air.

For a region to be "in attainment," hourly measurements of air pollution in that region must not exceed those designated to be safe by the Federal Clean Air Act.

For a region to be "in compliance," hourly measurements of air pollution in that region must not exceed those designated to be safe by the Federal Clean Air Act.

Release of pollutants into the air from a source.

A measurement of air pollution that exceeds the level designated to be safe by the Federal Clean Air Act in any given hour or on any given day.

A moving object that emits pollutants. Mobile sources are divided into two categories: on-road sources include cars, trucks, sport utility vehicles, motorcycles, and buses; off-road sources include airplanes, trains, motorboats and lawn mowers.

A criteria air pollutant. Nitrogen oxides are produced from burning fuels, including gasoline and coal. Nitrogen oxides react with volatile organic compounds (VOCs) to form ozone, the main component of urban smog. Nitrogen oxides are also a precursor pollutant that contributes to the formation of acid rain.