40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

§ 50.15 National primary and secondary ambient air quality standards for ozone.

(a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts per million (ppm), daily maximum 8-hour average, measured by a reference method based on appendix D to this part and designated in accordance with part 53 of this chapter or an equivalent method designated in accordance with part 53 of this chapter.

(b) The 8-hour primary and secondary O3 ambient air quality standards are met at an ambient air quality monitoring site when the 3-year average of the annual fourth-highest daily maximum 8-hour average O3 concentration is less than or equal to 0.075 ppm, as determined in accordance with appendix P to this part.

[ 73 FR 16511, Mar. 27, 2008]

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

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United States Code

Title 40 published on 2015-08-22

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 40 CFR Part 50 after this date.

  • 2017-04-14; vol. 82 # 71 - Friday, April 14, 2017
    1. 82 FR 17947 - Release of the Policy Assessment for the Review of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen
      GPO FDSys XML | Text
      ENVIRONMENTAL PROTECTION AGENCY
      Notice of availability.
      The NO 2 PA will be available on or about April 12, 2017.
      40 CFR Parts 50 and 58
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