The primary purpose of the Smoke Management Program (SMP) is to mitigate the effects of smoke from forestry related prescribed burning on Smoke Sensitive Areas (SSAs). The primary impetus is the Clean Air Act of 1970 and subsequent amendments in 1977 and 1990. The Clean Air Act established National Ambient Air Quality Standards (NAAQS) for the entire country. These standards are set for many different types of pollutants. However, the US Environmental Protection Agency (EPA) has determined that the primary health hazard concern from smoke emissions from prescribed burns is particulate matter of 2.5 microns in diameter or less, or PM2.5.