40 CFR 50.7 - National primary and secondary ambient air quality standards for PM 2.5 .

§ 50.7 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 65 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 micrograms per cubic meter.
(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 65 micrograms per cubic meter.
[62 FR 38711, July 18, 1997, as amended at 69 FR 45595, July 30, 2004]
Beta! The text on the eCFR tab represents the unofficial eCFR text at ecfr.gov.
§ 50.7 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/m 3) annual arithmetic mean concentration, and 65 µg/m 3 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 micrograms per cubic meter.

(c) The 24-hour primary and secondary PM2.5 standards are met when the 98 th percentile 24-hour concentration, as determined in accordance with appendix N of this part, is less than or equal to 65 micrograms per cubic meter.

[62 FR 38711, July 18, 1997, as amended at 69 FR 45595, July 30, 2004]

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United States Code

Title 40 published on 2015-07-01

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

  • 2015-11-20; vol. 80 # 224 - Friday, November 20, 2015
    1. 80 FR 72840 - Treatment of Data Influenced by Exceptional Events
      GPO FDSys XML | Text
      ENVIRONMENTAL PROTECTION AGENCY
      Proposed rule; notice of availability of related draft guidance; notice of hearing.
      Comments. Written comments on this proposal and draft guidance must be received by January 19, 2016. Public hearing: The EPA will hold a public hearing on this proposal on Tuesday, December 8, 2015, in Phoenix, Arizona. Please refer to SUPPLEMENTARY INFORMATION for additional information on the comment period and public hearing.
      40 CFR Part 50