40 CFR § 68.130 - List of substances.

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§ 68.130 List of substances.

(a) Regulated toxic and flammable substances under section 112(r) of the Clean Air Act are the substances listed in Tables 1, 2, 3, and 4. Threshold quantities for listed toxic and flammable substances are specified in the tables.

(b) The basis for placing toxic and flammable substances on the list of regulated substances are explained in the notes to the list.

Table 1 to § 68.130 - List of Regulated Toxic Substances and Threshold Quantities for Accidental Release Prevention

[Alphabetical Order - 77 Substances]

Chemical name CAS No. Threshold quantity (lbs) Basis for listing
Acrolein [2-Propenal] 107-02-8 5,000 b
Acrylonitrile [2-Propenenitrile] 107-13-1 20,000 b
Acrylyl chloride [2-Propenoyl chloride] 814-68-6 5,000 b
Allyl alcohol [2-Propen-l-ol] 107-18-6 15,000 b
Allylamine [2-Propen-l-amine] 107-11-9 10,000 b
Ammonia (anhydrous) 7664-41-7 10,000 a, b
Ammonia (conc 20% or greater) 7664-41-7 20,000 a, b
Arsenous trichloride 7784-34-1 15,000 b
Arsine 7784-42-1 1,000 b
Boron trichloride [Borane, trichloro-] 10294-34-5 5,000 b
Boron trifluoride [Borane, trifluoro-] 7637-07-2 5,000 b
Boron trifluoride compound with methyl ether (1:1) [Boron, trifluoro [oxybis [metane]]-, T-4- 353-42-4 15,000 b
Bromine 7726-95-6 10,000 a, b
Carbon disulfide 75-15-0 20,000 b
Chlorine 7782-50-5 2,500 a, b
Chlorine dioxide [Chlorine oxide (ClO2)] 10049-04-4 1,000 c
Chloroform [Methane, trichloro-] 67-66-3 20,000 b
Chloromethyl ether [Methane, oxybis[chloro-] 542-88-1 1,000 b
Chloromethyl methyl ether [Methane, chloromethoxy-] 107-30-2 5,000 b
Crotonaldehyde [2-Butenal] 4170-30-3 20,000 b
Crotonaldehyde, (E)- [2-Butenal, (E)-] 123-73-9 20,000 b
Cyanogen chloride 506-77-4 10,000 c
Cyclohexylamine [Cyclohexanamine] 108-91-8 15,000 b
Diborane 19287-45-7 2,500 b
Dimethyldichlorosilane [Silane, dichlorodimethyl-] 75-78-5 5,000 b
1,1-Dimethylhydrazine [Hydrazine, 1,1-dimethyl-] 57-14-7 15,000 b
Epichlorohydrin [Oxirane, (chloromethyl)-] 106-89-8 20,000 b
Ethylenediamine [1,2-Ethanediamine] 107-15-3 20,000 b
Ethyleneimine [Aziridine] 151-56-4 10,000 b
Ethylene oxide [Oxirane] 75-21-8 10,000 a, b
Fluorine 7782-41-4 1,000 b
Formaldehyde (solution) 50-00-0 15,000 b
Furan 110-00-9 5,000 b
Hydrazine 302-01-2 15,000 b
Hydrochloric acid (conc 37% or greater) 7647-01-0 15,000 d
Hydrocyanic acid 74-90-8 2,500 a, b
Hydrogen chloride (anhydrous) [Hydrochloric acid] 7647-01-0 5,000 a
Hydrogen fluoride/Hydrofluoric acid (conc 50% or greater) [Hydrofluoric acid] 7664-39-3 1,000 a, b
Hydrogen selenide 7783-07-5 500 b
Hydrogen sulfide 7783-06-4 10,000 a, b
Iron, pentacarbonyl- [Iron carbonyl (Fe(CO)5), (TB-5-11)-] 13463-40-6 2,500 b
Isobutyronitrile [Propanenitrile, 2-methyl-] 78-82-0 20,000 b
Isopropyl chloroformate [Carbonochloridic acid, 1-methylethyl ester] 108-23-6 15,000 b
Methacrylonitrile [2-Propenenitrile, 2-methyl-] 126-98-7 10,000 b
Methyl chloride [Methane, chloro-] 74-87-3 10,000 a
Methyl chloroformate [Carbonochloridic acid, methylester] 79-22-1 5,000 b
Methyl hydrazine [Hydrazine, methyl-] 60-34-4 15,000 b
Methyl isocyanate [Methane, isocyanato-] 624-83-9 10,000 a, b
Methyl mercaptan [Methanethiol] 74-93-1 10,000 b
Methyl thiocyanate [Thiocyanic acid, methyl ester] 556-64-9 20,000 b
Methyltrichlorosilane [Silane, trichloromethyl-] 75-79-6 5,000 b
Nickel carbonyl 13463-39-3 1,000 b
Nitric acid (conc 80% or greater) 7697-37-2 15,000 b
Nitric oxide [Nitrogen oxide (NO)] 10102-43-9 10,000 b
Oleum (Fuming Sulfuric acid) [Sulfuric acid, mixture with sulfur trioxide] 1 8014-95-7 10,000 e
Peracetic acid [Ethaneperoxoic acid] 79-21-0 10,000 b
Perchloromethylmercaptan [Methanesulfenyl chloride, trichloro-] 594-42-3 10,000 b
Phosgene [Carbonic dichloride] 75-44-5 500 a, b
Phosphine 7803-51-2 5,000 b
Phosphorus oxychloride [Phosphoryl chloride] 10025-87-3 5,000 b
Phosphorus trichloride [Phosphorous trichloride] 7719-12-2 15,000 b
Piperidine 110-89-4 15,000 b
Propionitrile [Propanenitrile] 107-12-0 10,000 b
Propyl chloroformate [Carbonochloridic acid, propylester] 109-61-5 15,000 b
Propyleneimine [Aziridine, 2-methyl-] 75-55-8 10,000 b
Propylene oxide [Oxirane, methyl-] 75-56-9 10,000 b
Sulfur dioxide (anhydrous) 7446-09-5 5,000 a, b
Sulfur tetrafluoride [Sulfur fluoride (SF4), (T-4)-] 7783-60-0 2,500 b
Sulfur trioxide 7446-11-9 10,000 a, b
Tetramethyllead [Plumbane, tetramethyl-] 75-74-1 10,000 b
Tetranitromethane [Methane, tetranitro-] 509-14-8 10,000 b
Titanium tetrachloride [Titanium chloride (TiCl4) (T-4)-] 7550-45-0 2,500 b
Toluene 2,4-diisocyanate [Benzene, 2,4-diisocyanato-1-methyl-] 1 584-84-9 10,000 a
Toluene 2,6-diisocyanate [Benzene, 1,3-diisocyanato-2-methyl-] 1 91-08-7 10,000 a
Toluene diisocyanate (unspecified isomer) [Benzene, 1,3-diisocyanatomethyl-] 1 26471-62-5 10,000 a
Trimethylchlorosilane [Silane, chlorotrimethyl-] 75-77-4 10,000 b
Vinyl acetate monomer [Acetic acid ethenyl ester] 108-05-4 15,000 b

1 The mixture exemption in § 68.115(b)(1) does not apply to the substance.

Note: Basis for Listing:

a Mandated for listing by Congress.

b On EHS list, vapor pressure 10 mmHg or greater.

c Toxic gas.

d Toxicity of hydrogen chloride, potential to release hydrogen chloride, and history of accidents.

e Toxicity of sulfur trioxide and sulfuric acid, potential to release sulfur trioxide, and history of accidents.

Table 2 to § 68.130 - List of Regulated Toxic Substances and Threshold Quantities for Accidental Release Prevention

[CAS Number Order - 77 Substances]

CAS No. Chemical name Threshold quantity (lbs) Basis for listing
50-00-0 Formaldehyde (solution) 15,000 b
57-14-7 1,1-Dimethylhydrazine [Hydrazine, 1,1-dimethyl-] 15,000 b
60-34-4 Methyl hydrazine [Hydrazine, methyl-] 15,000 b
67-66-3 Chloroform [Methane, trichloro-] 20,000 b
74-87-3 Methyl chloride [Methane, chloro-] 10,000 a
74-90-8 Hydrocyanic acid 2,500 a, b
74-93-1 Methyl mercaptan [Methanethiol] 10,000 b
75-15-0 Carbon disulfide 20,000 b
75-21-8 Ethylene oxide [Oxirane] 10,000 a, b
75-44-5 Phosgene [Carbonic dichloride] 500 a, b
75-55-8 Propyleneimine [Aziridine, 2-methyl-] 10,000 b
75-56-9 Propylene oxide [Oxirane, methyl-] 10,000 b
75-74-1 Tetramethyllead [Plumbane, tetramethyl-] 10,000 b
75-77-4 Trimethylchlorosilane [Silane, chlorotrimethyl-] 10,000 b
75-78-5 Dimethyldichlorosilane [Silane, dichlorodimethyl-] 5,000 b
75-79-6 Methyltrichlorosilane [Silane, trichloromethyl-] 5,000 b
78-82-0 Isobutyronitrile [Propanenitrile, 2-methyl-] 20,000 b
79-21-0 Peracetic acid [Ethaneperoxoic acid] 10,000 b
79-22-1 Methyl chloroformate [Carbonochloridic acid, methylester] 5,000 b
91-08-7 Toluene 2,6-diisocyanate [Benzene, 1,3-diisocyanato-2-methyl-] 1 10,000 a
106-89-8 Epichlorohydrin [Oxirane, (chloromethyl)-] 20,000 b
107-02-8 Acrolein [2-Propenal] 5,000 b
107-11-9 Allylamine [2-Propen-1-amine] 10,000 b
107-12-0 Propionitrile [Propanenitrile] 10,000 b
107-13-1 Acrylonitrile [2-Propenenitrile] 20,000 b
107-15-3 Ethylenediamine [1,2-Ethanediamine] 20,000 b
107-18-6 Allyl alcohol [2-Propen-1-ol] 15,000 b
107-30-2 Chloromethyl methyl ether [Methane, chloromethoxy-] 5,000 b
108-05-4 Vinyl acetate monomer [Acetic acid ethenyl ester] 15,000 b
108-23-6 Isopropyl chloroformate [Carbonochloridic acid, 1-methylethyl ester] 15,000 b
108-91-8 Cyclohexylamine [Cyclohexanamine] 15,000 b
109-61-5 Propyl chloroformate [Carbonochloridic acid, propylester] 15,000 b
110-00-9 Furan 5,000 b
110-89-4 Piperidine 15,000 b
123-73-9 Crotonaldehyde, (E)- [2-Butenal, (E)-] 20,000 b
126-98-7 Methacrylonitrile [2-Propenenitrile, 2-methyl-] 10,000 b
151-56-4 Ethyleneimine [Aziridine] 10,000 b
302-01-2 Hydrazine 15,000 b
353-42-4 Boron trifluoride compound with methyl ether (1:1) [Boron, trifluoro[oxybis[methane]]-, T-4- 15,000 b
506-77-4 Cyanogen chloride 10,000 c
509-14-8 Tetranitromethane [Methane, tetranitro-] 10,000 b
542-88-1 Chloromethyl ether [Methane, oxybis[chloro-] 1,000 b
556-64-9 Methyl thiocyanate [Thiocyanic acid, methyl ester] 20,000 b
584-84-9 Toluene 2,4-diisocyanate [Benzene, 2,4-diisocyanato-1-methyl-] 1 10,000 a
594-42-3 Perchloromethylmercaptan [Methanesulfenyl chloride, trichloro-] 10,000 b
624-83-9 Methyl isocyanate [Methane, isocyanato-] 10,000 a, b
814-68-6 Acrylyl chloride [2-Propenoyl chloride] 5,000 b
4170-30-3 Crotonaldehyde [2-Butenal] 20,000 b
7446-09-5 Sulfur dioxide (anhydrous) 5,000 a, b
7446-11-9 Sulfur trioxide 10,000 a, b
7550-45-0 Titanium tetrachloride [Titanium chloride (TiCl4) (T-4)-] 2,500 b
7637-07-2 Boron trifluoride [Borane, trifluoro-] 5,000 b
7647-01-0 Hydrochloric acid (conc 37% or greater) 15,000 d
7647-01-0 Hydrogen chloride (anhydrous) [Hydrochloric acid] 5,000 a
7664-39-3 Hydrogen fluoride/Hydrofluoric acid (conc 50% or greater) [Hydrofluoric acid] 1,000 a, b
7664-41-7 Ammonia (anhydrous) 10,000 a, b
7664-41-7 Ammonia (conc 20% or greater) 20,000 a, b
7697-37-2 Nitric acid (conc 80% or greater) 15,000 b
7719-12-2 Phosphorus trichloride [Phosphorous trichloride] 15,000 b
7726-95-6 Bromine 10,000 a, b
7782-41-4 Fluorine 1,000 b
7782-50-5 Chlorine 2,500 a, b
7783-06-4 Hydrogen sulfide 10,000 a, b
7783-07-5 Hydrogen selenide 500 b
7783-60-0 Sulfur tetrafluoride [Sulfur fluoride (SF4), (T-4)-] 2,500 b
7784-34-1 Arsenous trichloride 15,000 b
7784-42-1 Arsine 1,000 b
7803-51-2 Phosphine 5,000 b
8014-95-7 Oleum (Fuming Sulfuric acid) [Sulfuric acid, mixture with sulfur trioxide] 1 10,000 e
10025-87-3 Phosphorus oxychloride [Phosphoryl chloride] 5,000 b
10049-04-4 Chlorine dioxide [Chlorine oxide (ClO2)] 1,000 c
10102-43-9 Nitric oxide [Nitrogen oxide (NO)] 10,000 b
10294-34-5 Boron trichloride [Borane, trichloro-] 5,000 b
13463-39-3 Nickel carbonyl 1,000 b
13463-40-6 Iron, pentacarbonyl- [Iron carbonyl (Fe(CO)5), (TB-5-11)-] 2,500 b
19287-45-7 Diborane 2,500 b
26471-62-5 Toluene diisocyanate (unspecified isomer) [Benzene, 1,3-diisocyanatomethyl-1] 1 10,000 a

1 The mixture exemption in § 68.115(b)(1) does not apply to the substance.

Note: Basis for Listing:

a Mandated for listing by Congress.

b On EHS list, vapor pressure 10 mmHg or greater.

c Toxic gas.

d Toxicity of hydrogen chloride, potential to release hydrogen chloride, and history of accidents.

e Toxicity of sulfur trioxide and sulfuric acid, potential to release sulfur trioxide, and history of accidents.

Table 3 to § 68.130 - List of Regulated Flammable Substances 1 and Threshold Quantities for Accidental Release Prevention

[Alphabetical Order - 63 Substances]

Chemical name CAS No. Threshold quantity (lbs) Basis for listing
Acetaldehyde 75-07-0 10,000 g
Acetylene [Ethyne] 74-86-2 10,000 f
Bromotrifluorethylene [Ethene, bromotrifluoro-] 598-73-2 10,000 f
1,3-Butadiene 106-99-0 10,000 f
Butane 106-97-8 10,000 f
1-Butene 106-98-9 10,000 f
2-Butene 107-01-7 10,000 f
Butene 25167-67-3 10,000 f
2-Butene-cis 590-18-1 10,000 f
2-Butene-trans [2-Butene, (E)] 624-64-6 10,000 f
Carbon oxysulfide [Carbon oxide sulfide (COS)] 463-58-1 10,000 f
Chlorine monoxide [Chlorine oxide] 7791-21-1 10,000 f
2-Chloropropylene [1-Propene, 2-chloro-] 557-98-2 10,000 g
1-Chloropropylene [1-Propene, 1-chloro-] 590-21-6 10,000 g
Cyanogen [Ethanedinitrile] 460-19-5 10,000 f
Cyclopropane 75-19-4 10,000 f
Dichlorosilane [Silane, dichloro-] 4109-96-0 10,000 f
Difluoroethane [Ethane, 1,1-difluoro-] 75-37-6 10,000 f
Dimethylamine [Methanamine, N-methyl-] 124-40-3 10,000 f
2,2-Dimethylpropane [Propane, 2,2-dimethyl-] 463-82-1 10,000 f
Ethane 74-84-0 10,000 f
Ethyl acetylene [1-Butyne] 107-00-6 10,000 f
Ethylamine [Ethanamine] 75-04-7 10,000 f
Ethyl chloride [Ethane, chloro-] 75-00-3 10,000 f
Ethylene [Ethene] 74-85-1 10,000 f
Ethyl ether [Ethane, 1,1′-oxybis-] 60-29-7 10,000 g
Ethyl mercaptan [Ethanethiol] 75-08-1 10,000 g
Ethyl nitrite [Nitrous acid, ethyl ester] 109-95-5 10,000 f
Hydrogen 1333-74-0 10,000 f
Isobutane [Propane, 2-methyl] 75-28-5 10,000 f
Isopentane [Butane, 2-methyl-] 78-78-4 10,000 g
Isoprene [1,3-Butadinene, 2-methyl-] 78-79-5 10,000 g
Isopropylamine [2-Propanamine] 75-31-0 10,000 g
Isopropyl chloride [Propane, 2-chloro-] 75-29-6 10,000 g
Methane 74-82-8 10,000 f
Methylamine [Methanamine] 74-89-5 10,000 f
3-Methyl-1-butene 563-45-1 10,000 f
2-Methyl-1-butene 563-46-2 10,000 g
Methyl ether [Methane, oxybis-] 115-10-6 10,000 f
Methyl formate [Formic acid, methyl ester] 107-31-3 10,000 g
2-Methylpropene [1-Propene, 2-methyl-] 115-11-7 10,000 f
1,3-Pentadinene 504-60-9 10,000 f
Pentane 109-66-0 10,000 g
1-Pentene 109-67-1 10,000 g
2-Pentene, (E)- 646-04-8 10,000 g
2-Pentene, (Z)- 627-20-3 10,000 g
Propadiene [1,2-Propadiene] 463-49-0 10,000 f
Propane 74-98-6 10,000 f
Propylene [1-Propene] 115-07-1 10,000 f
Propyne [1-Propyne] 74-99-7 10,000 f
Silane 7803-62-5 10,000 f
Tetrafluoroethylene [Ethene, tetrafluoro-] 116-14-3 10,000 f
Tetramethylsilane [Silane, tetramethyl-] 75-76-3 10,000 g
Trichlorosilane [Silane, trichloro-] 10025-78-2 10,000 g
Trifluorochloroethylene [Ethene, chlorotrifluoro-] 79-38-9 10,000 f
Trimethylamine [Methanamine, N,N-dimethyl-] 75-50-3 10,000 f
Vinyl acetylene [1-Buten-3-yne] 689-97-4 10,000 f
Vinyl chloride [Ethene, chloro-] 75-01-4 10,000 a, f
Vinyl ethyl ether [Ethene, ethoxy-] 109-92-2 10,000 g
Vinyl fluoride [Ethene, fluoro-] 75-02-5 10,000 f
Vinylidene chloride [Ethene, 1,1-dichloro-] 75-35-4 10,000 g
Vinylidene fluoride [Ethene, 1,1-difluoro-] 75-38-7 10,000 f
Vinyl methyl ether [Ethene, methoxy-] 107-25-5 10,000 f

1 A flammable substance when used as a fuel or held for sale as a fuel at a retail facility is excluded from all provisions of this part (see § 68.126).

Note: Basis for Listing:

a Mandated for listing by Congress.

f Flammable gas.

g Volatile flammable liquid.

Table 4 to § 68.130 - List of Regulated Flammable Substances 1 and Threshold Quantities for Accidental Release Prevention

[CAS Number Order - 63 Substances]

CAS No. Chemical name Threshold quantity
(lbs)
Basis for listing
60-29-7 Ethyl ether [Ethane, 1,1′-oxybis-] 10,000 g
74-82-8 Methane 10,000 f
74-84-0 Ethane 10,000 f
74-85-1 Ethylene [Ethene] 10,000 f
74-86-2 Acetylene [Ethyne] 10,000 f
74-89-5 Methylamine [Methanamine] 10,000 f
74-98-6 Propane 10,000 f
74-99-7 Propyne [1-Propyne] 10,000 f
75-00-3 Ethyl chloride [Ethane, chloro-] 10,000 f
75-01-4 Vinyl chloride [Ethene, chloro-] 10,000 a, f
75-02-5 Vinyl fluoride [Ethene, fluoro-] 10,000 f
75-04-7 Ethylamine [Ethanamine] 10,000 f
75-07-0 Acetaldehyde 10,000 g
75-08-1 Ethyl mercaptan [Ethanethiol] 10,000 g
75-19-4 Cyclopropane 10,000 f
75-28-5 Isobutane [Propane, 2-methyl] 10,000 f
75-29-6 Isopropyl chloride [Propane, 2-chloro-] 10,000 g
75-31-0 Isopropylamine [2-Propanamine] 10,000 g
75-35-4 Vinylidene chloride [Ethene, 1,1-dichloro-] 10,000 g
75-37-6 Difluoroethane [Ethane, 1,1-difluoro-] 10,000 f
75-38-7 Vinylidene fluoride [Ethene, 1,1-difluoro-] 10,000 f
75-50-3 Trimethylamine [Methanamine, N, N-dimethyl-] 10,000 f
75-76-3 Tetramethylsilane [Silane, tetramethyl-] 10,000 g
78-78-4 Isopentane [Butane, 2-methyl-] 10,000 g
78-79-5 Isoprene [1,3,-Butadiene, 2-methyl-] 10,000 g
79-38-9 Trifluorochloroethylene [Ethene, chlorotrifluoro-] 10,000 f
106-97-8 Butane 10,000 f
106-98-9 1-Butene 10,000 f
106-99-0 1,3-Butadiene 10,000 f
107-00-6 Ethyl acetylene [1-Butyne] 10,000 f
107-01-7 2-Butene 10,000 f
107-25-5 Vinyl methyl ether [Ethene, methoxy-] 10,000 f
107-31-3 Methyl formate [Formic acid, methyl ester] 10,000 g
109-66-0 Pentane 10,000 g
109-67-1 1-Pentene 10,000 g
109-92-2 Vinyl ethyl ether [Ethene, ethoxy-] 10,000 g
109-95-5 Ethyl nitrite [Nitrous acid, ethyl ester] 10,000 f
115-07-1 Propylene [1-Propene] 10,000 f
115-10-6 Methyl ether [Methane, oxybis-] 10,000 f
115-11-7 2-Methylpropene [1-Propene, 2-methyl-] 10,000 f
116-14-3 Tetrafluoroethylene [Ethene, tetrafluoro-] 10,000 f
124-40-3 Dimethylamine [Methanamine, N-methyl-] 10,000 f
460-19-5 Cyanogen [Ethanedinitrile] 10,000 f
463-49-0 Propadiene [1,2-Propadiene] 10,000 f
463-58-1 Carbon oxysulfide [Carbon oxide sulfide (COS)] 10,000 f
463-82-1 2,2-Dimethylpropane [Propane, 2,2-dimethyl-] 10,000 f
504-60-9 1,3-Pentadiene 10,000 f
557-98-2 2-Chloropropylene [1-Propene, 2-chloro-] 10,000 g
563-45-1 3-Methyl-1-butene 10,000 f
563-46-2 2-Methyl-1-butene 10,000 g
590-18-1 2-Butene-cis 10,000 f
590-21-6 1-Chloropropylene [1-Propene, 1-chloro-] 10,000 g
598-73-2 Bromotrifluorethylene [Ethene, bromotrifluoro-] 10,000 f
624-64-6 2-Butene-trans [2-Butene, (E)] 10,000 f
627-20-3 2-Pentene, (Z)- 10,000 g
646-04-8 2-Pentene, (E)- 10,000 g
689-97-4 Vinyl acetylene [1-Buten-3-yne] 10,000 f
1333-74-0 Hydrogen 10,000 f
4109-96-0 Dichlorosilane [Silane, dichloro-] 10,000 f
7791-21-1 Chlorine monoxide [Chlorine oxide] 10,000 f
7803-62-5 Silane 10,000 f
10025-78-2 Trichlorosilane [Silane, trichloro-] 10,000 g
25167-67-3 Butene 10,000 f

1 A flammable substance when used as a fuel or held for sale as a fuel at a retail facility is excluded from all provisions of this part (see § 68.126).

Note: Basis for Listing:

a Mandated for listing by Congress.

f Flammable gas.

g Volatile flammable liquid.

[59 FR 4493, Jan. 31, 1994. Redesignated at 61 FR 31717, June 20, 1996, as amended at 62 FR 45132, Aug. 25, 1997; 63 FR 645, Jan. 6, 1998; 65 FR 13250, Mar. 13, 2000; 82 FR 4702, Jan. 13, 2017]