Hazardous Air Pollutants (HAPs) List

EPA has designated the following pollutants as hazardous under the 1990 Clean Air Act Amendments. These 188 pollutants (originally 189) were added as they are known to cause cancer and other serious health impacts.

  • 75070 Acetaldehyde (voc)
  • 60335 Acetamide (voc)
  • 75058 Acetonitrile (voc)
  • 98862 Acetophenone (voc)
  • 53963 2-Acetylaminofluorene (voc)
  • 107028 Acrolein (voc)
  • 79061 Acrylamide (voc)
  • 79107 Acrylic acid (voc)
  • 107131 Acrylonitrile (voc)
  • 107051 Allyl chloride (voc)
  • 92671 4-Aminobiphenyl (voc)
  • 62533 Aniline (voc)
  • 90040 o-Anisidine (voc)
  • 1332214 Asbestos (TSP)
  • 71432 Benzene (including benzene from gasoline) (voc)
  • 92875 Benzidine (voc)
  • 98077 Benzotrichloride (voc)
  • 100447 Benzyl chloride (voc)
  • 92524 Biphenyl (voc)
  • 117817 Bis(2-ethylhexyl)phthalate (DEHP) (voc)
  • 542881 Bis(chloromethyl)ether (voc)
  • 75252 Bromoform (voc)
  • 106945 1-Bromopropane (voc) - Added February 4, 2022
  • 106990 1,3-Butadiene (voc)
  • 156627 Calcium cyanamide (voc)
  • 105602 Caprolactam (voc) Delisted 61FR30816, 6/18/96
  • 133062 Captan (voc)
  • 63252 Carbaryl (voc)
  • 75150 Carbon disulfide (voc)
  • 56235 Carbon tetrachloride (voc)
  • 463581 Carbonyl sulfide (voc)
  • 120809 Catechol (voc)
  • 133904 Chloramben (voc)
  • 57749 Chlordane (voc)
  • 7782505 Chlorine
  • 79118 Chloroacetic acid (voc)
  • 532274 2-Chloroacetophenone (voc)
  • 108907 Chlorobenzene (voc)
  • 510156 Chlorobenzilate (voc)
  • 67663 Chloroform (voc)
  • 107302 Chloromethyl methyl ether (voc)
  • 126998 Chloroprene (voc)
  • 1319773 Cresols/Cresylic acid (isomers and mixture)(voc)
  • 95487 o-Cresol (voc)
  • 108394 m-Cresol (voc)
  • 106445 p-Cresol (voc)
  • 98828 Cumene (voc)
  • 94757 2,4-D, salts and esters (voc)
  • 3547044 DDE (voc)
  • 334883 Diazomethane (voc)
  • 132649 Dibenzofurans (voc)
  • 96128 1,2-Dibromo-3-chloropropane (voc)
  • 84742 Dibutylphthalate (voc)
  • 106467 1,4-Dichlorobenzene(p) (voc)
  • 91941 3,3-Dichlorobenzidene (voc)
  • 111444 Dichloroethyl ether (Bis(2-chloroethyl)ether)(voc)
  • 542756 1,3-Dichloropropene (voc)
  • 62737 Dichlorvos (voc)
  • 111422 Diethanolamine (voc)
  • 121697 N,N-Diethyl aniline (N,N-Dimethylaniline)(voc)
  • 64675 Diethyl sulfate (voc)
  • 119904 3,3-Dimethoxybenzidine (voc)
  • 60117 Dimethyl aminoazobenzene (voc)
  • 119937 3,3-Dimethyl benzidine (voc)
  • 79447 Dimethyl carbamoyl chloride (voc)
  • 68122 Dimethyl formamide (voc)
  • 57147 1,1-Dimethyl hydrazine (voc)
  • 131113 Dimethyl phthalate (voc)
  • 77781 Dimethyl sulfate (voc)
  • 534521 4,6-Dinitro-o-cresol, and salts (voc)
  • 51285 2,4-Dinitrophenol (voc)
  • 121142 2,4-Dinitrotoluene (voc)
  • 123911 1,4-Dioxane (1,4-Diethyleneoxide) (voc)
  • 122667 1,2-Diphenylhydrazine (voc)
  • 106898 Epichlorohydrin (I-Chloro-2,3-epoxypropane) (voc)
  • 106887 1,2-Epoxybutane (voc)
  • 140885 Ethyl acrylate (voc)
  • 100414 Ethyl benzene (voc)
  • 51796 Ethyl carbamate (Urethane) (voc)
  • 75003 Ethyl chloride (Chloroethane) (voc)
  • 106934 Ethylene dibromide (Dibromoethane) (voc)
  • 107062 Ethylene dichloride (1,2-Dichloroethane) (voc)
  • 107211 Ethylene glycol (voc)
  • 151564 Ethylene imine (Aziridine) (voc)
  • 75218 Ethylene oxide (voc)
  • 96457 Ethylene thiourea (voc)
  • 75343 Ethylidene dichloride (1,1-Dichloroethane) (voc)
  • 50000 Formaldehyde (voc)
  • 76448 Heptachlor (voc)
  • 118741 Hexachlorobenzene (voc)
  • 87683 Hexachlorobutadiene (voc)
  • 77474 Hexachlorocyclopentadiene (voc)
  • 67721 Hexachloroethane (voc)
  • 822060 Hexamethylene-1,6-diisocyanate (voc)
  • 680319 Hexamethylphosphoramide (voc)
  • 110543 Hexane (voc)
  • 302012 Hydrazine
  • 7647010 Hydrochloric acid
  • 7664393 Hydrogen fluoride (Hydrofluoric acid)
  • 123319 Hydroquinone (voc)
  • 78591 Isophorone (voc)
  • 58899 Lindane (all isomers) (voc)
  • 108316 Maleic anhydride (voc)
  • 67561 Methanol (voc)
  • 72435 Methoxychlor (voc)
  • 74839 Methyl bromide (Bromomethane) (voc)
  • 74873 Methyl chloride (Chloromethane) (voc)
  • 71556 Methyl chloroform (1,1,1-Trichloroethane)
  • 78933 Methyl ethyl ketone (2-Butanone) (voc) Delisted 12/19/2005
  • 60344 Methyl hydrazine (voc)
  • 74884 Methyl iodide (Iodomethane) (voc)
  • 108101 Methyl isobutyl ketone (Hexone) (voc)
  • 624839 Methyl isocyanate (voc)
  • 80626 Methyl methacrylate (voc)
  • 1634044 Methyl tert butyl ether (voc)
  • 101144 4,4-Methylene bis(2-chloroaniline) (voc)
  • 75092 Methylene chloride (Dichloromethane)
  • 101688 Methylene diphenyl diisocyanate (MDI) (voc)
  • 101779 4,4-Methylenedianiline (voc)
  • 91203 Naphthalene (voc)
  • 98953 Nitrobenzene (voc)
  • 92933 4-Nitrobiphenyl (voc)
  • 100027 4-Nitrophenol (voc)
  • 79469 2-Nitropropane (voc)
  • 684935 N-Nitroso-N-methylurea (voc)
  • 62759 N-Nitrosodimethylamine (voc)
  • 59892 N-Nitrosomorpholine (voc)
  • 56382 Parathion (voc)
  • 82688 Pentachloronitrobenzene (Quintobenzene) (voc)
  • 87865 Pentachlorophenol (voc)
  • 108952 Phenol (voc)
  • 106503 p-Phenylenediamine (voc)
  • 75445 Phosgene (voc)
  • 7803512 Phosphine
  • 7723140 Phosphorus (TSP)
  • 85449 Phthalic anhydride (voc)
  • 1336363 Polychlorinated biphenyls (Aroclors) (voc)
  • 1120714 1,3-Propane sultone (voc)
  • 57578 beta-Propiolactone (voc)
  • 123386 Propionaldehyde (voc)
  • 114261 Propoxur (Baygon) (voc)
  • 78875 Propylene dichloride (1,2-Dichloropropane) (voc)
  • 75569 Propylene oxide (voc)
  • 75558 1,2-Propylenimine (2-Methyl aziridine) (voc)
  • 91225 Quinoline (voc)
  • 106514 Quinone (voc)
  • 100425 Styrene (voc)
  • 96093 Styrene oxide (voc)
  • 1746016 2,3,7,8-Tetrachlorodibenzo-p-dioxin (voc)
  • 79345 1,1,2,2-Tetrachloroethane (voc)
  • 127184 Tetrachloroethylene (Perchloroethylene)
  • 7550450 Titanium tetrachloride (TSP)
  • 108883 Toluene (voc)
  • 95807 2,4-Toluene diamine (voc)
  • 84849 2,4-Toluene diisocyanate (voc)
  • 95534 o-Toluidine (voc)
  • 8001352 Toxaphene (chlorinated camphene) (voc)
  • 120821 1,2,4-Trichlorobenzene (voc)
  • 79005 1,1,2-Trichloroethane (voc)
  • 79016 Trichloroethylene (voc)
  • 95954 2,4,5-Trichlorophenol (voc)
  • 88062 2,4,6-Trichlorophenol (voc)
  • 121448 Triethylamine (voc)
  • 1582098 Trifluralin (voc)
  • 540841 2,2,4-Trimethylpentane (voc)
  • 108054 Vinyl acetate (voc)
  • 593602 Vinyl bromide (voc)
  • 75014 Vinyl chloride (voc)
  • 75354 Vinylidene chloride (1,1-Dichloroethylene) (voc)
  • 1330207 Xylenes (isomers and mixture) (voc)
  • 95476 o-Xylenes (voc)
  • 108383 m-Xylenes (voc)
  • 106423 p-Xylenes (voc)
  • 0 Antimony Compounds (TSP)
  • 0 Arsenic Compounds(inorganic including arsine)(TSP)
  • 0 Beryllium Compounds (TSP)
  • 0 Cadmium Compounds (TSP)
  • 0 Chromium Compounds (TSP)
  • 0 Cobalt Compounds (TSP)
  • 0 Coke Oven Emissions (voc)
  • 0 Cyanide Compounds 1 (TSP)
  • 0 Glycol ethers 2 (voc)
  • 0 Lead Compounds (TSP)
  • 0 Manganese Compounds (TSP)
  • 0 Mercury Compounds (TSP)
  • 0 Fine mineral fibers 3 (TSP)
  • 0 Nickel Compounds (TSP)
  • 0 Polycylic Organic Matter 4 (voc)
  • 0 Radionuclides (including radon)
  • 0 Selenium Compounds (TSP)

Note: 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. Revised per 65FR47342, 8/2/2000 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 or less
    • R = phenyl or alkyl substituted phenyl
    • R' = H or alkyl C7 or less
    • OR' consisting of carboxylic acid ester, Sulfate, phosphate, nitrate, or sulfonate
    • Ethylene Glycol monoButyl Ether (EGBE) was removed as a glycol ether compound on 11/29/2004
  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 100oC.
  5. A type of atom which spontaneously undergoes radioactive decay.