EPA has released the Final Policy Assessment for the Ozone National Ambient Air Quality Standards (PA, EPA–452/R–20–001). This document was prepared as part of the current review of the national ambient air quality standards (NAAQS) for photochemical oxidants including ozone (O3). The PA serves to “bridge the gap” between the currently available scientific and technical information and the judgments required of the Administrator in determining whether to retain or revise the existing O3 NAAQS. The primary and secondary O3 NAAQS are set to protect the public health and the public welfare from O3 and other photochemical oxidants in ambient air.
The final PA is available here: https://www.epa.gov/naaqs/ozone-o3-standards-policy-assessments-current-review