About Particulate Matter Regulation

Particulate Matter, PM 10 and PM 2.5, is one of the components of smoke of greatest concern from a regulatory standpoint.

Updates in 2024

On February 7, 2024, EPA strengthened the National Ambient Air Quality Standards for Particulate Matter (PM NAAQS) to protect millions of Americans from harmful and costly health impacts, such as heart attacks and premature death. ​Particle or soot pollution is one of the most dangerous forms of air pollution, and an extensive body of science links it to a range of serious and sometimes deadly illnesses. ​ EPA is setting the level of the primary (health-based) annual PM2.5 standard at 9.0 micrograms per cubic meter to provide increased public health protection, consistent with the available health science.

Visit the EPA's webpage on the rule to read summaries and additional information:

National Ambient Air Quality Standards (NAAQS) for PM