40 CFR 50.3 - Reference conditions.

§ 50.3 Reference conditions.

All measurements of air quality that are expressed as mass per unit volume (e.g., micrograms per cubic meter) other than for particulate matter (PM2.5) standards contained in §§ 50.7, 50.13, and 50.18, and lead standards contained in § 50.16 shall be corrected to a reference temperature of 25 (deg) C and a reference pressure of 760 millimeters of mercury (1,013.2 millibars). Measurements of PM2.5 for purposes of comparison to the standards contained in §§ 50.7, 50.13, and 50.18, and of lead for purposes of comparison to the standards contained in § 50.16 shall be reported based on actual ambient air volume measured at the actual ambient temperature and pressure at the monitoring site during the measurement period.

[ 78 FR 3277, Jan. 15, 2013]

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.

  • 2017-03-28; vol. 82 # 58 - Tuesday, March 28, 2017
    1. 82 FR 15310 - Response to December 9, 2013, Clean Air Act Section 176A Petition From Connecticut, Delaware, Maryland, Massachusetts, New Hampshire, New York, Pennsylvania, Rhode Island and Vermont
      GPO FDSys XML | Text
      Notice of public hearing and extension of comment period.
      Comments. Comments must be received on or before May 15, 2017. Public Hearing. The public hearing will be held on April 13, 2017, in Washington, DC. Please refer to SUPPLEMENTARY INFORMATION section for additional information on the public hearing.
      40 CFR Parts 50 and 51
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