Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

  • Environmental Topics
  • Laws & Regulations
  • Report a Violation
  • About EPA
Risk Assessment
Contact Us

Integrated Science Assessment (ISA) for Ozone and Related Photochemical Oxidants (Final Report, Apr 2020)

On this page:

  • Overview
  • History
  • Downloads

Alert
Alert Notice

EPA's announced the availability of the final Integrated Science Assessment for Ozone and Related Photochemical Oxidants in an April 20, 2020 Federal Register Notice.

Abstract

The Integrated Science Assessment for Ozone and Related Photochemical Oxidants 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 and Related Photochemical Oxidants under the Clean Air Act. Welfare effects are non-health effects which, according to the Clean Air Act include, but are not limited to, effects on soils, water, crops, vegetation, animals, wildlife and climate. The Ozone ISA, in conjunction with additional technical and policy assessments, provides the policy relevant scientific information necessary to conduct a review of the current primary and secondary air quality standards for Ozone sufficiently protects public health and welfare.
EPA has established NAAQS for six criteria pollutants. Presently the EPA is reviewing the air quality criteria and NAAQS for photochemical oxidants and ozone; ozone is the current indicator for this NAAQS. Periodically, EPA reviews the scientific basis for these standards by preparing an Integrated Science Assessment (ISA). The ISA, in conjunction with additional technical and policy assessments, provides the policy relevant scientific information necessary to conduct a review 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.

Impact/Purpose

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.

Citation

U.S. EPA. Integrated Science Assessment (ISA) for Ozone and Related Photochemical Oxidants (Final Report, Apr 2020). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-20/012, 2020.

History/Chronology

Date Description
13- Jun 2018 EPA put out a call for scientific and policy relevant papers in preparation of developing an updated Integrated Review Plan (IRP) and an Integrated Science Assessment (ISA) as part of the 5- year review of the air quality criteria and the National Ambient Air Quality Standards (NAAQS) this one specific to Ozone (O3) and related photochemical oxidants. [Federal Register Jun 26, 2018]
14- Oct/Nov 2018 EPA held a series of webinar workshops to evaluate initial draft materials for the Integrated Science Assessment for Ozone and Related Photochemical Oxidants on October 29 and 31, 2018, and November 1 and 5, 2018.
15- Sep 2019 EPA released the document Integrated Science Assessment for Ozone and Related Photochemical Oxidants (External Review Draft) (EPA/600/R-19/093) for public review and comment.[Federal Register Sep 26, 2019]
17- Dec 2019 The Clean Air Scientific Advisory Committee (CASAC) convened at a public meeting on February 11-12, 2020 to review the draft Ozone ISA.
18- Feb 2020 EPA's Science Advisory Board (SAB) released the Draft CASAC Review of the EPA’s Integrated Science Assessment for Ozone and Related Photochemical Oxidants (External Review Draft – September 2019).
19- Apr 2020 EPA updated the ISA based on CASAC comments on the draft and released the final report.
20- Sep 2021 EPA re-posts the final assessment with an errata sheet of the update.

Download(s)

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.

  • Integrated Science Assessment (ISA) for Ozone and Related Photochemical Oxidants (Apr 2020) (PDF)  (1468  pp, 20.1 MB, about PDF)
  • 1. ISA for Ozone - Executive Summary (PDF)  (22  pp, 1.3 MB, about PDF)
  • 2. ISA for Ozone - Integrated Synthesis (Main) (PDF)  (101  pp, 1.9 MB, about PDF)
  • Errata Sheet (PDF)  (1  pp, 125.0 KB, about PDF)

Related Link(s)

  • Preamble To The Integrated Science Assessments (ISA)
  • Integrated Science Assessment (ISA) for Ozone and Related Photochemical Oxidants (External Review Draft, Sep 2019)

Get the Report

cover-image-link

Federal Register Notices

  • FR Notice: Apr 20, 2020
  • Risk Assessment Home
  • About Risk Assessment
  • Risk Recent Additions
  • Human Health Risk Assessment
  • Ecological Risk Assessment
  • Risk Advanced Search
    • Risk Publications
  • Risk Assessment Guidance
  • Risk Tools and Databases
  • Superfund Risk Assessment
  • Where you live
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on October 20, 2020
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshots
  • Grants
  • No FEAR Act Data
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Open Government
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.