Ozone National Ambient Air Quality Standards (NAAQS)
On this page:
0.070 parts per million (ppm), as the fourth-highest daily maximum 8-hour concentration, averaged across three consecutive years.
- 12/23/2020 - Review of the Ozone NAAQS - Final Decision
- 7/13/2020 - Review of the Ozone NAAQS - Proposed Decision
- Fact Sheet on the Decision
- Basic Information and Fact Sheets Regarding 2015 Revision to 2008 Ozone National Ambient Air Quality Standards (NAAQS)