40 CFR 50.13 - National primary and secondary ambient air quality standards for PM 2.5 .

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There is 1 rule appearing in the Federal Register for 40 CFR 50. View below or at eCFR (GPOAccess)
§ 50.13 National primary and secondary ambient air quality standards for PM2.5.
(a) The national primary and secondary ambient air quality standards for particulate matter are 15.0 micrograms per cubic meter (µg/m3) annual arithmetic mean concentration, and 35 µg/m3 24-hour average concentration measured in the ambient air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers) by either:
(1) A reference method based on appendix L of this part and designated in accordance with part 53 of this chapter; or
(2) An equivalent method designated in accordance with part 53 of this chapter.
(b) The annual primary and secondary PM2.5 standards are met when the annual arithmetic mean concentration, as determined in accordance with appendix N of this part, is less than or equal to 15.0 µg/m3.
(c) The 24-hour primary and secondary PM2.5 standards are met when the 98th percentile 24-hour concentration, as determined in accordance with appendix N of this part, is less than or equal to 35 µg/m3.
[71 FR 61224, Oct. 17, 2006]

Title 40 published on 2013-07-01

The following are only the Rules published in the Federal Register after the published date of Title 40.

For a complete list of all Rules, Proposed Rules, and Notices view the Rulemaking tab.

  • 2013-07-03; vol. 78 # 128 - Wednesday, July 3, 2013
    1. 78 FR 40000 - Method for the Determination of Lead in Total Suspended Particulate Matter
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      ENVIRONMENTAL PROTECTION AGENCY
      Final rule.
      This final rule is effective on August 2, 2013.
      40 CFR Part 50

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United States Code

Title 40 published on 2013-07-01

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

  • 2014-02-13; vol. 79 # 30 - Thursday, February 13, 2014
    1. 79 FR 8644 - Notice of Workshop in Support of the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur
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      ENVIRONMENTAL PROTECTION AGENCY
      Notice of workshop.
      The workshop will be held March 4-6, 2014. The pre-registration deadline is February 28, 2014.
      40 CFR Part 50