Air pollution — the introduction by man, directly or indirectly, of substances or energy into the air resulting in deleterious effects of such a nature as to endanger human health, harm living resources and ecosystems and material property and impair or interfere with amenities and other legitimate uses of the environment art_2__para

Air quality limit values — the concentration of polluting substances in the air during a specified period which is not to be exceeded 4.

Emission limit values — the concentration and/or mass of polluting substances in emissions from plants during a specified period which is not to be exceeded 5.

Existing plant — a plant in operation before 1 July 1987 or built or authorized before that date 3.

Plant — any establishment or other stationary plant used for industrial or public utility purposes which is likely to cause air pollution 2.