2012 National Ambient Air Quality Standards (NAAQS) for Particulate Matter (PM)
In 2012, based on EPA’s review of the air quality criteria and the national ambient air quality standards (NAAQS) for particulate matter (PM), the EPA revised the annual PM2.5 standards, and made related revisions in:
- data handling conventions
- the Air Quality Index (AQI)
- the ambient air monitoring, reporting and network design requirements
- regulations for the prevention of significant deterioration (PSD) program
The EPA retained the existing primary (health-based) and secondary (welfare-based) 24-hour standards for PM2.5 and PM10, without revision.
01/15/2013 – Final Rule