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 and 50.13 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 and 50.13 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.
[73 FR 67051, Nov. 12, 2008]

Title 40 published on 2014-07-01

no entries appear in the Federal Register after this date.

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.

This list is taken from the Parallel Table of Authorities and Rules provided by GPO [Government Printing Office].

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United States Code

Title 40 published on 2014-07-01

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

  • 2015-01-05; vol. 80 # 2 - Monday, January 5, 2015
    1. 80 FR 278 - National Ambient Air Quality Standards for Lead
      GPO FDSys XML | Text
      Proposed rule.
      Comments must be received on or before April 6, 2015. Public Hearings: If, by January 26, 2015, the EPA receives a request from a member of the public to speak at a public hearing concerning the proposed decision, we will hold a public hearing, with information about the hearing provided in a subsequent notice in the Federal Register .
      40 CFR Part 50