National Ambient Air Quality Standards (NAAQS)

National Ambient Air Quality Standards are set by the EPA under the authority of Section 109 of the Clean Air Act. The standards set maximums for the amount certain air pollutants, sometimes referred as criteria pollutants in the US.

There are six criteria pollutants that these standards regulate. These are carbon monoxide, lead, nitrogen dioxide, particulate matter, ozone, and sulfur dioxide. Of these, the two main pollutants of concern with respect to fire are particulate matter and ozone.

Source:U.S. EPA. "National Ambient Air Quality Standards". Air and Radiation. 2012. Accessed on 9 September 2013. Available at