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.
- 7/13/2020 - Review of the Ozone NAAQS - Proposed Decision
- Fact Sheet on the Proposed Decision
- Virtual Public Hearing - EPA intends to hold two virtual public hearings approximately 15 days after publication in the Federal Register of this proposal. Registration will begin when the proposal publishes in the Federal Register.
- Basic Information and Fact Sheets Regarding 2015 Revision to 2008 Ozone National Ambient Air Quality Standards (NAAQS)