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National Emissions Standards for Hazardous Air Pollutants

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The National Emissions Standards for Hazardous Air Pollutants, also using the acronym NESHAP, are emissions standards set by the United States Environmental Protection Agency—EPA. The standards are for air pollutants not covered by National Ambient Air Quality Standards—NAAQS, that may cause an increase in fatalities or in serious, irreversible, or incapacitating illness.

Contents

MACT standards

The standards for a particular source category require the maximum degree of emission reduction that the EPA determines to be achievable, which is known as the Maximum Achievable Control Technology—MACT standards. These standards are authorized by Section 112 of the 1970 Clean Air Act and the regulations are published in 40 CFR Parts 61 and 63.

Pollutants

The USEPA regulates the following hazardous air pollutants via the MACT standards:

For all listings above which contain the word "compounds" and for glycol ethers, the following applies: Unless otherwise specified, these listings are defined as including any unique chemical substance that contains the named chemical (i.e., antimony, arsenic, etc.) as part of that chemical's infrastructure.

  • ^1 X'CN where X = H' or any other group where a formal dissociation may occur. For example, KCN or Ca(CN)2
  • ^2 Includes mono- and di- ethers of ethylene glycol, diethylene glycol, and triethylene glycol R-(OCH2CH2)n -OR' where
    • n = 1, 2, or 3 R = alkyl C7 (chain of 7 carbon atoms) or less; or phenyl or alkyl substituted phenyl R' = H or alkyl C7 or less; or OR' consisting of carboxylic acid ester, sulfate, phosphate, nitrate, or sulfonate. Polymers are excluded from the glycol category, as well as surfactant alcohol ethoxylates (where R is an alkyl C8 or greater) and their derivatives, and ethylene glycol monobutyl ether (CAS 111-76-2).
  • ^3 Includes mineral fiber emissions from facilities manufacturing or processing glass, rock, or slag fibers (or other mineral derived fibers) of average diameter 1 micrometer or less.
  • ^4 Includes organic compounds with more than one benzene ring, and which have a boiling point greater than or equal to 100 °C.
  • ^5 A type of atom which spontaneously undergoes radioactive decay.

    • Sources: USEPA's original list & Modifications

    References

    National Emissions Standards for Hazardous Air Pollutants Wikipedia
    (Text) CC BY-SA