US EPA

The Integrated Science Assessment for Ozone and Related Photochemical Oxidants document is a concise synthesis and evaluation of the most policy-relevant science, and has been prepared as part of the review of the primary (health-based) and secondary (welfare-based) National Ambient Air Quality Standards (NAAQS) for Ozone under the Clean Air Act. When final, the Ozone ISA, in conjunction with additional technical and policy assessments, will provide the scientific basis for EPA's decision on whether the current primary and secondary air quality standards for Ozone sufficiently protects public health and welfare.

Ozone (O₃) is one of six principal (or criteria) pollutants for which EPA has established NAAQS. The Clean Air Act requires EPA to periodically review the scientific basis for these standards by preparing an Integrated Science Assessment (ISA). The ISA, in conjunction with additional technical and policy assessments, provide the scientific basis for EPA decisions on the adequacy of the current NAAQS and the appropriateness of possible alternative standards. These reviews play a significant role in EPA’s commitment to ensuring a clean and healthy environment for the public.

This report provides critical evaluation and integration of the evidence on health and environmental effects of ozone to support EPA's Office of Air with the review of the NAAQS for ozone.

In December 2019, the Clean Air Scientific Advisory Committee (CASAC) will host a public meeting to review the draft Ozone ISA. Then a second draft will be released in 2020, which will address CASAC and public comments received on the first draft ISA. Once final, the complete ISA will be posted on the EPA Web site to provide the scientific basis for EPA’s periodic review and possible revision of the primary NAAQS for Ozone and Related Photochemical Oxidants.

U.S. EPA. Integrated Science Assessment (ISA) for Ozone and Related Photochemical Oxidants (External Review Draft, Sep 2019). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-19/093, 2019.

A limited number of CD-ROM copies will be available. Contact Ms. Marieka Boyd by phone: 919-541-0031; fax: 919-541-5078; or email: boyd.marieka@epa.gov to request a CD-ROM, and please provide your name, your mailing address, and the document title, “Integrated Science Assessment for Ozone and Related Photochemical Oxidants (External Review Draft)” to facilitate processing of your request.