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Air Quality

Section 112(r) of the Clean Air Act
Accidental Release Prevention Program

Below is a listing of the chemicals [with Chemical Abstract Service (CAS) number and threshold quantity in pounds] which are regulated under accidental release requirements of the Clean Air Act.

Regulated Substance CAS # Threshold Quantity
1,1-Dichloroethylene 75354 10,000
1,1-Dimethyl hydrazine 57147 15,000
1,2-Ethanediamine 107153 20,000
1,2-Propadiene 463490 10,000
1,3-Butadiene 106990 10,000
1,3-Butadiene, 2-methyl- 78795 10,000
1,3-Pentadiene 504609 10,000
1-Buten-3-yne 689974 10,000
1-Butene 106989 10,000
1-Butyne 107006 10,000
1-Chloropropylene 590216 10,000
1-Pentene 109671 10,000
1-Propene 115071 10,000
1-Propene, 1-chloro- 590216 10,000
1-Propene, 2-chloro- 557982 10,000
1-Propene, 2-methyl- 115117 10,000
1-Propyne 74997 10,000
2,2-Dimethylpropane 463821 10,000
2-Butenal 4170303 20,000
2-Butenal, (e)- 123739 20,000
2-Butene 107017 10,000
2-Butene, (E) 624646 10,000
2-Butene-cis 590181 10,000
2-Butene-trans 624646 10,000
2-Chloropropylene 557982 10,000
2-Methyl-1-butene 563462 10,000
2-Methylpropene 115117 10,000
2-Pentene, (E)- 646048 10,000
2-Pentene, (Z)- 627203 10,000
2-Propanamine 75310 10,000
2-Propen-1-amine 107119 10,000
2-Propen-1-ol 107186 15,000
2-Propenal 107028 5,000
2-Propenenitrile 107131 20,000
2-Propenenitrile, 2-methyl- 126987 10,000
2-Propenoyl chloride 814686 5,000
3-Methyl-1-butene 563451 10,000
Acetaldehyde 75070 10,000
Acetic acid ethenyl ester 108054 15,000
Acetylene 74862 10,000
Acrolein 107028 5,000
Acrylonitrile 107131 20,000
Acrylyl chloride 814686 5,000
Allyl alcohol 107186 15,000
Allylamine 107119 10,000
Ammonia (anhydrous) 7664417 10,000
Ammonia (conc 20% or greater) 7664417 20,000
Arsenous trichloride 7784341 15,000
Arsine 7784421 1,000
Aziridine 151564 10,000
Aziridine, 2-methyl 75558 10,000
Benzene, 1,3-diisocyanato-2-methyl- 91087 10,000
Benzene, 1,3-diisocyanatomethyl- 26471625 10,000
Benzene, 2,4-diisocyanato-1-methyl- 584849 10,000
Bis(chloromethyl) ether 542881 1,000
Borane, trichloro- 10294345 5,000
Borane, trifluoro- 7637072 5,000
Boron trichloride 10294345 5,000
Boron trifluoride 7637072 5,000
Boron trifluoride compound with methyl ether (1:1) 353424 15,000
Boron, trifluoro[oxybis[methane]]-, (T-4)- 353424 15,000
Bromine 7726956 10,000
Bromotrifluoroethylene 598732 10,000
Butane 106978 10,000
Butane, 2-methyl- 78784 10,000
Butene 25167673 10,000
Carbon disulfide 75150 20,000
Carbon oxide sulfide (COS) 463581 10,000
Carbonic dichloride 75445 500
Carbonochloridic acid, 1-methylethyl ester 108236 15,000
Carbonochloridic acid, methylester 79221 5,000
Carbonochloridic acid, propylester 109615 15,000
Carbonyl sulfide 463581 10,000
Chlorine 7782505 2,500
Chlorine dioxide 10049044 1,000
Chlorine monoxide 7791211 10,000
Chlorine oxide 7791211 10,000
Chlorine oxide (ClO2) 10049044 1,000
Chloroethane 75003 10,000
Chloroform 67663 20,000
Chloromethane 74873 10,000
Chloromethyl ether 542881 1,000
Chloromethyl methyl ether 107302 5,000
Crotonaldehyde 4170303 20,000
Crotonaldehyde, (E)- 123739 20,000
Cyanogen 460195 10,000
Cyanogen chloride 506774 10,000
Cyanogen chloride ((CN)Cl) 506774 10,000
Cyclohexanamine 108918 15,000
Cyclohexylamine 108918 15,000
Cyclopropane 75194 10,000
Diborane 19287457 2,500
Diborane(6) 19287457 2,500
Dichloromethyl ether 542881 1,000
Dichlorosilane 4109960 10,000
Difluoroethane 75376 10,000
Dimethylamine 124403 10,000
Dimethyldichlorosilane 75785 5,000
Dimethylhydrazine 57147 15,000
Epichlorohydrin 106898 20,000
Ethanamine 75047 10,000
Ethane 74840 10,000
Ethane, 1,1-difluoro- 75376 10,000
Ethane, 1,1'-oxybis- 60297 10,000
Ethane, chloro- 75003 10,000
Ethanedinitrile 460195 10,000
Ethaneperoxoic acid 79210 10,000
Ethanethiol 75081 10,000
Ethene 74851 10,000
Ethene, 1,1-dichloro- 75354 10,000
Ethene, 1,1-difluoro- 75387 10,000
Ethene, bromotrifluoro- 598732 10,000
Ethene, chloro- 75014 10,000
Ethene, chlorotrifluoro- 79389 10,000
Ethene, ethoxy- 109922 10,000
Ethene, fluoro- 75025 10,000
Ethene, methoxy- 107255 10,000
Ethene, tetrafluoro- 116143 10,000
Ethyl acetylene 107006 10,000
Ethyl chloride 75003 10,000
Ethyl cyanide 107120 10,000
Ethyl ether 60297 10,000
Ethyl mercaptan 75081 10,000
Ethyl nitrite 109955 10,000
Ethylene 74851 10,000
Ethylene oxide 75218 10,000
Ethylenediamine 107153 20,000
Ethyleneimine 151564 10,000
Ethyne 74862 10,000
Fluorine 7782414 1,000
Formaldehyde 50000 15,000
Formaldehyde (solution) 50000 15,000
Formic acid, methyl ester 107313 10,000
Furan 110009 5,000
Hydrazine 302012 15,000
Hydrazine, 1,1-dimethyl- 57147 15,000
Hydrazine, methyl- 60344 15,000
Hydrochloric acid (conc 37% or greater) 7647010 15,000
Hydrocyanic acid 74908 2,500
Hydrofluoric acid (conc. 50% or greater) 7664393 1,000
Hydrogen 1333740 10,000
Hydrogen chloride (anhydrous) 7647010 5,000
Hydrogen chloride (gas only) 7647010 5,000
Hydrogen cyanide 74908 2,500
Hydrogen fluoride (anhydrous) 7664393 1,000
Hydrogen selenide 7783075 500
Hydrogen sulfide 7783064 10,000
Iron carbonyl (Fe(CO)5), (TB-5-11)- 13463406 2,500
Iron, pentacarbonyl- 13463406 2,500
Isobutane 75285 10,000
Isobutyronitrile 78820 20,000
Isopentane 78784 10,000
Isoprene 78795 10,000
Isopropyl chloride 75296 10,000
Isopropyl chloroformate 108236 15,000
Isopropylamine 75310 10,000
Methacrylonitrile 126987 10,000
Methanamine 74895 10,000
Methanamine, N,N-dimethyl- 75503 10,000
Methanamine, N-methyl- 124403 10,000
Methane 74828 10,000
Methane, chloro- 74873 10,000
Methane, chloromethoxy- 107302 5,000
Methane, isocyanato- 624839 10,000
Methane, oxybis- 115106 10,000
Methane, oxybis[chloro- 542881 1,000
Methane, tetranitro- 509148 10,000
Methane, trichloro- 67663 20,000
Methanesulfenyl chloride, trichloro- 594423 10,000
Methanethiol 74931 10,000
Methyl chloride 74873 10,000
Methyl chlorocarbonate 79221 5,000
Methyl chloroformate 79221 5,000
Methyl ether 115106 10,000
Methyl formate 107313 10,000
Methyl hydrazine 60344 15,000
Methyl isocyanate 624839 10,000
Methyl mercaptan 74931 10,000
Methyl thiocyanate 556649 20,000
Methyltrichlorosilane 75796 5,000
Monoethylamine 75047 10,000
Monomethylamine 74895 10,000
Nickel carbonyl 13463393 1,000
Nitric acid (conc 80% or greater) 7697372 15,000
Nitric oxide 10102439 10,000
Nitrogen oxide (NO) 10102439 10,000
Nitrous acid, ethyl ester 109955 10,000
Oleum (fuming sulfuric acid) 8014957 10,000
Oxirane 75218 10,000
Oxirane, (chloromethyl)- 106898 20,000
Oxirane, methyl- 75569 10,000
Pentane 109660 10,000
Peracetic acid 79210 10,000
Perchloromethyl mercaptan 594423 10,000
Phosgene 75445 500
Phosphine 7803512 5,000
Phosphorous trichloride 7719122 15,000
Phosphorus oxychloride 10025873 5,000
Phosphorus trichloride 7719122 15,000
Phosphoryl chloride 10025873 5,000
Piperidine 110894 15,000
Plumbane, tetramethyl- 75741 10,000
Propadiene 463490 10,000
Propane 74986 10,000
Propane, 2,2-dimethyl- 463821 10,000
Propane, 2-chloro- 75296 10,000
Propane, 2-methyl 75285 10,000
Propanenitrile 107120 10,000
Propanenitrile, 2-methyl- 78820 20,000
Propene 115071 10,000
Propionitrile 107120 10,000
Propyl chloroformate 109615 15,000
Propylene 115071 10,000
Propylene oxide 75569 10,000
Propyleneimine 75558 10,000
Propyne 74997 10,000
Silane 7803625 10,000
Silane, chlorotrimethyl- 75774 10,000
Silane, dichloro- 4109960 10,000
Silane, dichlorodimethyl- 75785 5,000
Silane, tetramethyl- 75763 10,000
Silane, trichloro- 10025782 10,000
Silane, trichloromethyl- 75796 5,000
Sulfur dioxide (anhydrous) 7446095 5,000
Sulfur fluoride (SF4), (T-4)- 7783600 2,500
Sulfur tetrafluoride 7783600 2,500
Sulfur trioxide 7446119 10,000
Sulfuric acid (fuming) 8014957 10,000
Sulfuric acid, mixture with sulfur trioxide 8014957 10,000
Tetrafluoroethylene 116143 10,000
Tetramethyllead 75741 10,000
Tetramethylsilane 75763 10,000
Tetranitromethane 509148 10,000
Thiocyanic acid, methyl ester 556649 20,000
Thiomethanol 74931 10,000
Titanium chloride (TiCl4) (T-4)- 7550450 2,500
Titanium tetrachloride 7550450 2,500
Toluene diisocyanate (unspecified isomer) 26471625 10,000
Toluene-2,4-diisocyanate 584849 10,000
Toluene-2,6-diisocyanate 91087 10,000
Toluenediisocyanate (mixed isomers) 26471625 10,000
Trichloromethanesulfenyl chloride 594423 10,000
Trichlorosilane 10025782 10,000
Trifluorochloroethylene 79389 10,000
Trimethylamine 75503 10,000
Trimethylchlorosilane 75774 10,000
Vinyl acetate 108054 15,000
Vinyl acetate monomer 108054 15,000
Vinyl acetylene 689974 10,000
Vinyl chloride 75014 10,000
Vinyl ethyl ether 109922 10,000
Vinyl fluoride 75025 10,000
Vinyl methyl ether 107255 10,000
Vinylidene chloride 75354 10,000
Vinylidene fluoride 75387 10,000

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