US EPA

This first external review draft of the Air Quality Criteria for Ozone and Related Photochemical Oxidants (Ozone Criteria Document) is being released in January 2005 for public comment and for review by EPA's Clean Air Scientific Advisory Committee (CASAC) review. The public comment period ends May 2, 2005 and written comments should be sent to EPA, as indicated in the January 31, 2005 Federal Register notice announcing the public availability of this draft document for comment.

Background:

The Clean Air Act mandates periodic review of the National Ambient Air Quality Standards (NAAQS) for six common air pollutants, also referred to as criteria pollutants, including ozone. Under the review process, EPA's Office of Research and Development develops a criteria document -- a compilation and evaluation by U.S. EPA scientific staff and other expert authors of the latest scientific knowledge useful in assessing the health and welfare effects of the air pollutant. In this case, the Ozone Criteria Document presents the latest available pertinent information on atmospheric science, air quality, exposure, dosimetry, health effects, and environmental effects of ozone and other related photochemical oxidants. In developing criteria documents, EPA must consider the advice of CASAC. Learn more about the National Ambient Air Quality Standards.

Ozone Criteria Document Chronology:

• September 2000: The latest mandated periodic update revision of the Ozone Criteria Document began.
• December 2002: CASAC and the public reviewed and commented on a Project Work Plan for the Ozone Criteria Document.
• 2003-04: EPA prepared initial draft chapters of the Ozone Criteria Document, which were discussed at peer consultation meetings.
• 2004: EPA revised the chapters, taking into account comments from those peer consultation meetings.
• January 2005: EPA releases the first external review draft of the Ozone Criteria Document.

Next Steps:

CASAC will hold a public meeting to review this draft Ozone Criteria Document in early May 2005. A subsequent Federal Register notice will announce the meeting date and location. EPA will then review comments on the first draft from the public and CASAC. After reviewing them, we will issue a second draft and accept further comment from the public and CASAC. We will then issue the final version by February 28, 2006.

See description.

U.S. EPA. Air Quality Criteria for Ozone and Related Photochemical Oxidants (First External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/004aA-cA, 2005.