Air pollution episode

Air Pollution Episode
A period of abnormally high concentration of air pollutants, often due to low winds and temperature inversion, that can cause illness and death. (See episode, pollution.)
Source: Terms of the Environment ...

(See> air pollution episode.)
Emergency Exemption
Provision in FIFRA under which EPA can grant temporary exemption to a state or another federal agency to allow the use of a pesticide product not registered for that particular use.

Inversion- A layer of warm air that prevents the rise of cooling air and traps pollutants beneath it; can cause an air pollution episode.
Ion- An electrically charged atom or group of atoms.

See also: Solution, Air pollution, Air, Episode, Pollution