The National Emissions Standards for Hazardous Air Pollutants (NESHAPs) are emissions standards set by the United States EPA for an air pollutant not covered by NAAQS that may cause an increase in fatalities or in serious, irreversible, or incapacitating illness. 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) [1]. These standards are authorized by Section 112 of the Clean Air Act and the regulations are published in 40 CFR Parts 61 and 63.
Contents |
The USEPA regulates the following hazardous air pollutants via the MACT standards:
| CAS Number | Chemical Name | Notes |
|---|---|---|
| 75-07-0 | Acetaldehyde | |
| 60-35-5 | Acetamide | |
| 75-05-8 | Acetonitrile | |
| 98-86-2 | Acetophenone (Methyl Phenyl Ketone) | |
| 53-96-3 | 2-Acetylaminofluorene | |
| 107-02-8 | Acrolein | |
| 79-06-1 | Acrylamide | |
| 79-10-7 | Acrylic acid | |
| 107-13-1 | Acrylonitrile | |
| 107-05-1 | Allyl chloride (3-Chloropropene) | |
| 92-67-1 | 4-Aminobiphenyl | |
| 62-53-3 | Aniline | |
| 90-04-0 | o-Anisidine | |
| 1332-21-4 | Asbestos | |
| 71-43-2 | Benzene | including benzene from gasoline |
| 92-87-5 | Benzidine | |
| 98-07-7 | Benzotrichloride | |
| 100-44-7 | Benzyl chloride | |
| 92-52-4 | Biphenyl | |
| 117-81-7 | Bis(2-ethylhexyl)phthalate (DEHP) | |
| 542-88-1 | Bis(chloromethyl)ether | |
| 75-25-2 | Bromoform (Tribromomethane) | |
| 106-99-0 | 1,3-Butadiene | |
| 156-62-7 | Calcium cyanamide | |
| 105-60-2 | Caprolactam | delisted on June 18, 1996 |
| 133-06-2 | Captan | |
| 63-25-2 | Carbaryl | |
| 75-15-0 | Carbon disulfide | |
| 56-23-5 | Carbon tetrachloride (Tetrachloromethane) | |
| 463-58-1 | Carbonyl sulfide | |
| 120-80-9 | Catechol | |
| 133-90-4 | Chloramben | |
| 57-74-9 | Chlordane | |
| 7782-50-5 | Chlorine | |
| 79-11-8 | Chloroacetic acid | |
| 532-27-4 | 2-Chloroacetophenone | |
| 108-90-7 | Chlorobenzene | |
| 510-15-6 | Chlorobenzilate | |
| 67-66-3 | Chloroform (Trichloromethane) | |
| 107-30-2 | Chloromethyl methyl ether | |
| 126-99-8 | Chloroprene | |
| 1319-77-3 | Cresols/Cresylic acid (isomers and mixture) | |
| 95-48-7 | o-Cresol | |
| 108-39-4 | m-Cresol | |
| 106-44-5 | p-Cresol | |
| 98-82-8 | Cumene | |
| 94-75-7 | 2,4-D, salts and esters | |
| 3547-04-4 | Dichlorodiphenyldichloroethylene (DDE) | |
| 334-88-3 | Diazomethane | |
| 132-64-9 | Dibenzofurans | |
| 96-12-8 | 1,2-Dibromo-3-chloropropane (DBCP) | |
| 84-74-2 | Dibutylphthalate | |
| 106-46-7 | 1,4-Dichlorobenzene (p-Dichlorobenzene) | |
| 91-94-1 | 3,3'-Dichlorobenzidine | |
| 111-44-4 | Dichloroethyl ether (Bis(2-chloroethyl)ether) | |
| 542-75-6 | 1,3-Dichloropropene | |
| 62-73-7 | Dichlorvos | |
| 111-42-2 | Diethanolamine | |
| 64-67-5 | Diethyl sulfate | |
| 119-90-4 | 3,3'-Dimethoxybenzidine | |
| 60-11-7 | Dimethyl aminoazobenzene | |
| 119-93-7 | 3,3'-Dimethyl benzidine | |
| 79-44-7 | Dimethyl carbamoyl chloride | |
| 68-12-2 | Dimethyl formamide | |
| 57-14-7 | 1,1-Dimethyl hydrazine | |
| 131-11-3 | Dimethyl phthalate | |
| 77-78-1 | Dimethyl sulfate | |
| 121-69-7 | N,N-Dimethylaniline | Clean Air Act erroneously lists N,N-Diethylaniline |
| 534-52-1 | 4,6-Dinitro-o-cresol, and salts | |
| 51-28-5 | 2,4-Dinitrophenol | |
| 121-14-2 | 2,4-Dinitrotoluene | |
| 123-91-1 | 1,4-Dioxane (1,4-Diethyleneoxide) | |
| 122-66-7 | 1,2-Diphenylhydrazine | |
| 106-89-8 | Epichlorohydrin (l-Chloro-2,3-epoxypropane) | |
| 106-88-7 | 1,2-Epoxybutane | |
| 140-88-5 | Ethyl acrylate | |
| 100-41-4 | Ethyl benzene | |
| 51-79-6 | Ethyl carbamate (Urethane) | |
| 75-00-3 | Ethyl chloride (Chloroethane) | |
| 106-93-4 | Ethylene dibromide (1,2-Dibromoethane) | |
| 107-06-2 | Ethylene dichloride (1,2-Dichloroethane) | |
| 107-21-1 | Ethylene glycol | |
| 151-56-4 | Ethylene imine (Aziridine) | |
| 75-21-8 | Ethylene oxide | |
| 96-45-7 | Ethylene thiourea | |
| 75-34-3 | Ethylidene dichloride (1,1-Dichloroethane) | |
| 50-00-0 | Formaldehyde | |
| 76-44-8 | Heptachlor | |
| 118-74-1 | Hexachlorobenzene | |
| 87-68-3 | Hexachlorobutadiene | |
| 77-47-4 | Hexachlorocyclopentadiene | |
| 67-72-1 | Hexachloroethane | |
| 822-06-0 | Hexamethylene-1,6-diisocyanate | |
| 680-31-9 | Hexamethylphosphoramide | |
| 110-54-3 | Hexane | |
| 302-01-2 | Hydrazine | |
| 7647-01-0 | Hydrochloric acid | |
| 7664-39-3 | Hydrogen fluoride (Hydrofluoric acid) | |
| 7783-06-4 | Hydrogen sulfide | delisted on December 4, 1991 |
| 123-31-9 | Hydroquinone | |
| 78-59-1 | Isophorone | |
| 58-89-9 | Lindane (all isomers) | |
| 108-31-6 | Maleic anhydride | |
| 67-56-1 | Methanol | |
| 72-43-5 | Methoxychlor | |
| 74-83-9 | Methyl bromide (Bromomethane) | |
| 74-87-3 | Methyl chloride (Chloromethane) | |
| 71-55-6 | Methyl chloroform (1,1,1-Trichloroethane) | |
| 78-93-3 | Methyl ethyl ketone (2-Butanone or MEK) | delisted on December 19, 2005 |
| 60-34-4 | Methyl hydrazine | |
| 74-88-4 | Methyl iodide (Iodomethane) | |
| 108-10-1 | Methyl isobutyl ketone (Hexone or MIBK) | currently under review for delisting |
| 624-83-9 | Methyl isocyanate | |
| 80-62-6 | Methyl methacrylate | |
| 1634-04-4 | Methyl tert-butyl ether | |
| 101-14-4 | 4,4'-Methylene bis(2-chloroaniline) | |
| 75-09-2 | Methylene chloride (Dichloromethane) | |
| 101-68-8 | Methylene diphenyl diisocyanate (MDI) | currently under review for delisting |
| 101-77-9 | 4,4'-Methylenedianiline | |
| 91-20-3 | Naphthalene | |
| 98-95-3 | Nitrobenzene | |
| 92-93-3 | 4-Nitrobiphenyl | |
| 100-02-7 | 4-Nitrophenol | |
| 79-46-9 | 2-Nitropropane | |
| 684-93-5 | N-Nitroso-N-methylurea | |
| 62-75-9 | N-Nitrosodimethylamine | |
| 59-89-2 | N-Nitrosomorpholine | |
| 56-38-2 | Parathion | |
| 82-68-8 | Pentachloronitrobenzene (Quintobenzene) | |
| 87-86-5 | Pentachlorophenol | |
| 108-95-2 | Phenol | |
| 106-50-3 | p-Phenylenediamine | |
| 75-44-5 | Phosgene | |
| 7803-51-2 | Phosphine | |
| 7723-14-0 | Phosphorus | |
| 85-44-9 | Phthalic anhydride | |
| 1336-36-3 | Polychlorinated biphenyls (Aroclors) | |
| 1120-71-4 | 1,3-Propane sultone | |
| 57-57-8 | beta-Propiolactone | |
| 123-38-6 | Propionaldehyde | |
| 114-26-1 | Propoxur (Baygon) | |
| 78-87-5 | Propylene dichloride (1,2-Dichloropropane) | |
| 75-56-9 | Propylene oxide | |
| 75-55-8 | 1,2-Propylenimine (2-Methyl aziridine) | |
| 91-22-5 | Quinoline | |
| 106-51-4 | Quinone | |
| 100-42-5 | Styrene | |
| 96-09-3 | Styrene oxide | |
| 1746-01-6 | 2,3,7,8-Tetrachlorodibenzo-p-dioxin | |
| 79-34-5 | 1,1,2,2-Tetrachloroethane | |
| 127-18-4 | Tetrachloroethylene (Perchloroethylene) | |
| 7550-45-0 | Titanium tetrachloride | |
| 108-88-3 | Toluene | |
| 95-80-7 | 2,4-Toluene diamine | |
| 584-84-9 | 2,4-Toluene diisocyanate | |
| 95-53-4 | o-Toluidine | |
| 8001-35-2 | Toxaphene (chlorinated camphene) | |
| 120-82-1 | 1,2,4-Trichlorobenzene | |
| 79-00-5 | 1,1,2-Trichloroethane | |
| 79-01-6 | Trichloroethylene | |
| 95-95-4 | 2,4,5-Trichlorophenol | |
| 88-06-2 | 2,4,6-Trichlorophenol | |
| 121-44-8 | Triethylamine | |
| 1582-09-8 | Trifluralin | |
| 540-84-1 | 2,2,4-Trimethylpentane | |
| 108-05-4 | Vinyl acetate | |
| 593-60-2 | Vinyl bromide (Bromoethene) | |
| 75-01-4 | Vinyl chloride (Chloroethene) | |
| 75-35-4 | Vinylidene chloride (1,1-Dichloroethylene) | |
| 1330-20-7 | Xylenes (isomers and mixture) | |
| 95-47-6 | o-Xylenes | |
| 108-38-3 | m-Xylenes | |
| 106-42-3 | p-Xylenes | |
| n/a | Antimony Compounds | |
| n/a | Arsenic Compounds | inorganic including arsine |
| n/a | Beryllium Compounds | |
| n/a | Cadmium Compounds | |
| n/a | Chromium Compounds | |
| n/a | Cobalt Compounds | |
| n/a | Coke Oven Emissions | |
| n/a | Cyanide Compounds1 | |
| n/a | Glycol ethers2 | |
| n/a | Lead Compounds | |
| n/a | Manganese Compounds | |
| n/a | Mercury Compounds | |
| n/a | Fine mineral fibers3 | |
| n/a | Nickel Compounds | |
| n/a | Polycylic Organic Matter4 | |
| n/a | Radionuclides5 | including radon |
| n/a | Selenium Compounds |
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.
Sources: USEPA's original list & Modifications
Most air toxics originate from human-made sources, including mobile sources (e.g., cars, trucks, buses) and stationary sources (e.g., factories, refineries, power plants), as well as indoor sources (e.g., building materials and activities such as cleaning). There are two types of stationary sources that generate routine emissions of air toxics:
"Major" sources are defined as sources that emit 10 tons per year of any of the listed toxic air pollutants, or 25 tons per year of a mixture of air toxics. These sources may release air toxics from equipment leaks, when materials are transferred from one location to another, or during discharge through emission stacks or vents
"Area" sources consist of smaller-size facilities that release lesser quantities of toxic pollutants into the air. Area sources are defined as sources that emit less than 10 tons per year of a single air toxic, or less than 25 tons per year of a combination of air toxics. Though emissions from individual area sources are often relatively small, collectively their emissions can be of concern - particularly where large numbers of sources are located in heavily populated areas.
The United States EPA published the initial list of "source categories" in 1992 (57FR31576, July 16, 1992) and since that time has issued several revisions and updates to the list and promulgation schedule. For each listed source category, EPA indicates whether the sources are considered to be "major" sources or "area" sources. The 1990 Clean Air Act Amendments direct EPA to set standards for all major sources of air toxics (and some area sources that are of particular concern). [2]