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Regulatory Development and Retrospective Review Tracker

Review of the NO2 Primary National Ambient Air Quality Standards (NAAQS)

a.k.a. NO2 NAAQS Review

RIN: 2060-AR57 (What's this?)

Docket No.: Not yet available (What's this?)

Current Phase: Pre-Proposal (What's this?)

Under the Clean Air Act Amendments of 1977, EPA is required to review the science upon which the national ambient air quality standards (NAAQS) are based and the standards themselves every 5 years. On February 9, 2010, EPA published a final rule revising the primary (health-based) NO2 NAAQS to provide increased protection for public health.

In that rule, EPA added a new 1-hour NO2 standard, with a level of 100 ppb, to the existing annual standard, with a level of 53 ppb. EPA has now initiated the next review of the primary NO2 NAAQS. This new review includes the preparation of an Integrated Review Plan, an Integrated Science Assessment, and, if warranted, a Risk/Exposure Assessment, and also a Policy Assessment by EPA, with opportunities for review by EPA's Clean Air Scientific Advisory Committee and the public. These documents will inform the Administrator's proposed decision as to whether to retain or revise the current standards. This decision will be published in the Federal Register with opportunity provided for public comment. The Administrator's final decisions will take into consideration the assessment documents, CASAC advice, and public comment on the proposed decision.

NPRM: Published in FR00/0000 (projected)

Potential Effects

Children's Health
This rule is likely to address an adverse impact on childhood lifestages, including prenatal (via exposure to women of childbearing age). The potential adverse impacts are expected to be due to toxicity (i.e., the developing fetus, infants, and/or children are more likely to have an adverse response than adult lifestages).

Participate / Learn More Regulatory Review

Some of EPA's rulemakings undergo regulatory review (What's this?), as prescribed by Executive Order 12866 and coordinated by the Office of Management and Budget (OMB). The following list describes which of this rulemaking's stages have completed review and published in the Federal Register, if any, and provides links to the review documents where available. Consult the "Timeline" section of this Web page for the dates of each review.

  • NPRM - No Information Available.
Citations & Authorities

Code of Federal Regulations (CFR) Citation
40 CFR 50 40 CFR 58

Legal Authority
Clean Air Act Title I


This site provides summaries of priority rulemakings and priority retrospective reviews of existing regulations. We update most of the site at the beginning of each month, though some data is updated more frequently if it is time sensitive. The information on this site is not intended to and does not commit EPA to specific conclusions or actions. For example, after further analysis, EPA may decide the effects of a rule would be different or it may decide to terminate a rulemaking.

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