From the text ... 'Prescribed fire is an important forestry tool in the states of Virginia, North Carolina, and South Carolina. It is used primarily for hazard reduction, site preparation and other types of silvicultural purposes. Burning in all three states is done under permit with the state forestry agency, and all three states make use of a voluntary Smoke Management Plan. The Smoke Management Plan links the state agency responsible for air pollution control very closely with the state forestry agency. Forestry burning is generally exempt from control under the air pollution control agency, unless an extreme air stagnation condition develops -- in that case all outside burning is usually forbidden.'