40 CFR 50.8 - National primary ambient air quality standards for carbon monoxide.

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There is 1 rule appearing in the Federal Register for 40 CFR 50. View below or at eCFR (GPOAccess)
§ 50.8 National primary ambient air quality standards for carbon monoxide.
(a) The national primary ambient air quality standards for carbon monoxide are:
(1) 9 parts per million (10 milligrams per cubic meter) for an 8-hour average concentration not to be exceeded more than once per year and
(2) 35 parts per million (40 milligrams per cubic meter) for a 1-hour average concentration not to be exceeded more than once per year.
(b) The levels of carbon monoxide in the ambient air shall be measured by:
(1) A reference method based on appendix C and designated in accordance with part 53 of this chapter, or
(2) An equivalent method designated in accordance with part 53 of this chapter.
(c) An 8-hour average shall be considered valid if at least 75 percent of the hourly average for the 8-hour period are available. In the event that only six (or seven) hourly averages are available, the 8-hour average shall be computed on the basis of the hours available using six (or seven) as the divisor.
(d) When summarizing data for comparision with the standards, averages shall be stated to one decimal place. Comparison of the data with the levels of the standards in parts per million shall be made in terms of integers with fractional parts of 0.5 or greater rounding up.
[50 FR 37501, Sept. 13, 1985]

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