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ATS Testifies in Support of More Protective Ozone Standard
This week, ATS testified before the Clean Air Scientific Advisory Committee (CASAC) supporting the EPA’s issuing a more protective National Ambient Air Quality Standard for ozone exposure. CASAC is an external panel of experts convened by the EPA to provide the agency scientific and policy guidance on the health effects of air pollution.

EPA staff is recommending that the agency retain the current ozone standard of 70 ppb over eight hours. The ATS and several other medical and environmental organizations support a more protective standard of 60 ppb. During the CASAC meeting, the ATS noted a wide range of well-constructed scientific studies that clearly show significant adverse health effects from exposure to ozone at levels below the current 70 ppb standard.

While the CASAC panel has not finalized its recommendations, it appears that all but one of the CASAC panel members agrees the current ozone standard is not protective and the EPA should consider a more protective standard in the range of 55-60 ppb. CASAC is expected to finalize is recommendations to EPA leadership in May. The EPA Administrator is ultimately responsible for choosing whether to revise the ozone standard and at what level. The EPA Administrator is not obligated to follow CASAC’s recommendation, but the Administrator does have to justify any standard that does not follow the panel’s recommendations.
Last Reviewed: April 2023