View Rule

Under the Clean Air Act Amendments of 1977, EPA is required to review and if appropriate revise the air quality criteria for the primary (health-based) and secondary (welfare-based) national ambient air quality standards (NAAQS) every 5 years. On December 31, 2020, EPA published a final decision retaining the ozone (O3) NAAQS. As directed in Executive Order 13990, "Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis," signed by President Biden on January 20, 2021, EPA undertook a review of the December 2020 decision. Based on that review, EPA is undertaking a reconsideration of the December 31, 2020 decision. As part of this reconsideration, EPA intends to develop a policy assessment for the reconsideration to take into account all of the policy-relevant information developed throughout the 2020 review, and to engage with the Clean Air Scientific Advisory Committee (CASAC) and a newly-constituted expert O3 panel.