View all text of Subpart F [§ 68.100 - § 68.130]

§ 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]107-02-85,000b Acrylonitrile [2-Propenenitrile]107-13-120,000b Acrylyl chloride [2-Propenoyl chloride]814-68-65,000b Allyl alcohol [2-Propen-l-ol]107-18-615,000b Allylamine [2-Propen-l-amine]107-11-910,000b Ammonia (anhydrous)7664-41-710,000a, b Ammonia (conc 20% or greater)7664-41-720,000a, b Arsenous trichloride7784-34-115,000b Arsine7784-42-11,000b Boron trichloride [Borane, trichloro-]10294-34-55,000b Boron trifluoride [Borane, trifluoro-]7637-07-25,000b Boron trifluoride compound with methyl ether (1:1) [Boron, trifluoro [oxybis [metane]]-, T-4-353-42-415,000b Bromine7726-95-610,000a, b Carbon disulfide75-15-020,000b Chlorine7782-50-52,500a, b Chlorine dioxide [Chlorine oxide (ClO2)]10049-04-41,000c Chloroform [Methane, trichloro-]67-66-320,000b Chloromethyl ether [Methane, oxybis[chloro-]542-88-11,000b Chloromethyl methyl ether [Methane, chloromethoxy-]107-30-25,000b Crotonaldehyde [2-Butenal]4170-30-320,000b Crotonaldehyde, (E)- [2-Butenal, (E)-]123-73-920,000b Cyanogen chloride506-77-410,000c Cyclohexylamine [Cyclohexanamine]108-91-815,000b Diborane19287-45-72,500b Dimethyldichlorosilane [Silane, dichlorodimethyl-]75-78-55,000b 1,1-Dimethylhydrazine [Hydrazine, 1,1-dimethyl-]57-14-715,000b Epichlorohydrin [Oxirane, (chloromethyl)-]106-89-820,000b Ethylenediamine [1,2-Ethanediamine]107-15-320,000b Ethyleneimine [Aziridine]151-56-410,000b Ethylene oxide [Oxirane]75-21-810,000a, b Fluorine7782-41-41,000b Formaldehyde (solution)50-00-015,000b Furan110-00-95,000b Hydrazine302-01-215,000b Hydrochloric acid (conc 37% or greater)7647-01-015,000d Hydrocyanic acid74-90-82,500a, b Hydrogen chloride (anhydrous) [Hydrochloric acid]7647-01-05,000a Hydrogen fluoride/Hydrofluoric acid (conc 50% or greater) [Hydrofluoric acid]7664-39-31,000a, b Hydrogen selenide7783-07-5500b Hydrogen sulfide7783-06-410,000a, b Iron, pentacarbonyl- [Iron carbonyl (Fe(CO)5), (TB-5-11)-]13463-40-62,500b Isobutyronitrile [Propanenitrile, 2-methyl-]78-82-020,000b Isopropyl chloroformate [Carbonochloridic acid, 1-methylethyl ester]108-23-615,000b Methacrylonitrile [2-Propenenitrile, 2-methyl-]126-98-710,000b Methyl chloride [Methane, chloro-]74-87-310,000a Methyl chloroformate [Carbonochloridic acid, methylester]79-22-15,000b Methyl hydrazine [Hydrazine, methyl-]60-34-415,000b Methyl isocyanate [Methane, isocyanato-]624-83-910,000a, b Methyl mercaptan [Methanethiol]74-93-110,000b Methyl thiocyanate [Thiocyanic acid, methyl ester]556-64-920,000b Methyltrichlorosilane [Silane, trichloromethyl-]75-79-65,000b Nickel carbonyl13463-39-31,000b Nitric acid (conc 80% or greater)7697-37-215,000b Nitric oxide [Nitrogen oxide (NO)]10102-43-910,000b Oleum (Fuming Sulfuric acid) [Sulfuric acid, mixture with sulfur trioxide] 18014-95-710,000e Peracetic acid [Ethaneperoxoic acid]79-21-010,000b Perchloromethylmercaptan [Methanesulfenyl chloride, trichloro-]594-42-310,000b Phosgene [Carbonic dichloride]75-44-5500a, b Phosphine7803-51-25,000b Phosphorus oxychloride [Phosphoryl chloride]10025-87-35,000b Phosphorus trichloride [Phosphorous trichloride]7719-12-215,000b Piperidine110-89-415,000b Propionitrile [Propanenitrile]107-12-010,000b Propyl chloroformate [Carbonochloridic acid, propylester]109-61-515,000b Propyleneimine [Aziridine, 2-methyl-]75-55-810,000b Propylene oxide [Oxirane, methyl-]75-56-910,000b Sulfur dioxide (anhydrous)7446-09-55,000a, b Sulfur tetrafluoride [Sulfur fluoride (SF4), (T-4)-]7783-60-02,500b Sulfur trioxide7446-11-910,000a, b Tetramethyllead [Plumbane, tetramethyl-]75-74-110,000b Tetranitromethane [Methane, tetranitro-]509-14-810,000b Titanium tetrachloride [Titanium chloride (TiCl4) (T-4)-]7550-45-02,500b Toluene 2,4-diisocyanate [Benzene, 2,4-diisocyanato-1-methyl-] 1584-84-910,000a Toluene 2,6-diisocyanate [Benzene, 1,3-diisocyanato-2-methyl-] 191-08-710,000a Toluene diisocyanate (unspecified isomer) [Benzene, 1,3-diisocyanatomethyl-] 126471-62-510,000a Trimethylchlorosilane [Silane, chlorotrimethyl-]75-77-410,000b Vinyl acetate monomer [Acetic acid ethenyl ester]108-05-415,000b

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 50-00-0Formaldehyde (solution)15,000b 57-14-71,1-Dimethylhydrazine [Hydrazine, 1,1-dimethyl-]15,000b 60-34-4Methyl hydrazine [Hydrazine, methyl-]15,000b 67-66-3Chloroform [Methane, trichloro-]20,000b 74-87-3Methyl chloride [Methane, chloro-]10,000a 74-90-8Hydrocyanic acid2,500a, b 74-93-1Methyl mercaptan [Methanethiol]10,000b 75-15-0Carbon disulfide20,000b 75-21-8Ethylene oxide [Oxirane]10,000a, b 75-44-5Phosgene [Carbonic dichloride]500a, b 75-55-8Propyleneimine [Aziridine, 2-methyl-]10,000b 75-56-9Propylene oxide [Oxirane, methyl-]10,000b 75-74-1Tetramethyllead [Plumbane, tetramethyl-]10,000b 75-77-4Trimethylchlorosilane [Silane, chlorotrimethyl-]10,000b 75-78-5Dimethyldichlorosilane [Silane, dichlorodimethyl-]5,000b 75-79-6Methyltrichlorosilane [Silane, trichloromethyl-]5,000b 78-82-0Isobutyronitrile [Propanenitrile, 2-methyl-]20,000b 79-21-0Peracetic acid [Ethaneperoxoic acid]10,000b 79-22-1Methyl chloroformate [Carbonochloridic acid, methylester]5,000b 91-08-7Toluene 2,6-diisocyanate [Benzene, 1,3-diisocyanato-2-methyl-] 110,000a 106-89-8Epichlorohydrin [Oxirane, (chloromethyl)-]20,000b 107-02-8Acrolein [2-Propenal]5,000b 107-11-9Allylamine [2-Propen-1-amine]10,000b 107-12-0Propionitrile [Propanenitrile]10,000b 107-13-1Acrylonitrile [2-Propenenitrile]20,000b 107-15-3Ethylenediamine [1,2-Ethanediamine]20,000b 107-18-6Allyl alcohol [2-Propen-1-ol]15,000b 107-30-2Chloromethyl methyl ether [Methane, chloromethoxy-]5,000b 108-05-4Vinyl acetate monomer [Acetic acid ethenyl ester]15,000b 108-23-6Isopropyl chloroformate [Carbonochloridic acid, 1-methylethyl ester]15,000b 108-91-8Cyclohexylamine [Cyclohexanamine]15,000b 109-61-5Propyl chloroformate [Carbonochloridic acid, propylester]15,000b 110-00-9Furan5,000b 110-89-4Piperidine15,000b 123-73-9Crotonaldehyde, (E)- [2-Butenal, (E)-]20,000b 126-98-7Methacrylonitrile [2-Propenenitrile, 2-methyl-]10,000b 151-56-4Ethyleneimine [Aziridine]10,000b 302-01-2Hydrazine15,000b 353-42-4Boron trifluoride compound with methyl ether (1:1) [Boron, trifluoro[oxybis[methane]]-, T-4-15,000b 506-77-4Cyanogen chloride10,000c 509-14-8Tetranitromethane [Methane, tetranitro-]10,000b 542-88-1Chloromethyl ether [Methane, oxybis[chloro-]1,000b 556-64-9Methyl thiocyanate [Thiocyanic acid, methyl ester]20,000b 584-84-9Toluene 2,4-diisocyanate [Benzene, 2,4-diisocyanato-1-methyl-] 110,000a 594-42-3Perchloromethylmercaptan [Methanesulfenyl chloride, trichloro-]10,000b 624-83-9Methyl isocyanate [Methane, isocyanato-]10,000a, b 814-68-6Acrylyl chloride [2-Propenoyl chloride]5,000b 4170-30-3Crotonaldehyde [2-Butenal]20,000b 7446-09-5Sulfur dioxide (anhydrous)5,000a, b 7446-11-9Sulfur trioxide10,000a, b 7550-45-0Titanium tetrachloride [Titanium chloride (TiCl4) (T-4)-]2,500b 7637-07-2Boron trifluoride [Borane, trifluoro-]5,000b 7647-01-0Hydrochloric acid (conc 37% or greater)15,000d 7647-01-0Hydrogen chloride (anhydrous) [Hydrochloric acid]5,000a 7664-39-3Hydrogen fluoride/Hydrofluoric acid (conc 50% or greater) [Hydrofluoric acid]1,000a, b 7664-41-7Ammonia (anhydrous)10,000a, b 7664-41-7Ammonia (conc 20% or greater)20,000a, b 7697-37-2Nitric acid (conc 80% or greater)15,000b 7719-12-2Phosphorus trichloride [Phosphorous trichloride]15,000b 7726-95-6Bromine10,000a, b 7782-41-4Fluorine1,000b 7782-50-5Chlorine2,500a, b 7783-06-4Hydrogen sulfide10,000a, b 7783-07-5Hydrogen selenide500b 7783-60-0Sulfur tetrafluoride [Sulfur fluoride (SF4), (T-4)-]2,500b 7784-34-1Arsenous trichloride15,000b 7784-42-1Arsine1,000b 7803-51-2Phosphine5,000b 8014-95-7Oleum (Fuming Sulfuric acid) [Sulfuric acid, mixture with sulfur trioxide] 110,000e 10025-87-3Phosphorus oxychloride [Phosphoryl chloride]5,000b 10049-04-4Chlorine dioxide [Chlorine oxide (ClO2)]1,000c 10102-43-9Nitric oxide [Nitrogen oxide (NO)]10,000b 10294-34-5Boron trichloride [Borane, trichloro-]5,000b 13463-39-3Nickel carbonyl1,000b 13463-40-6Iron, pentacarbonyl- [Iron carbonyl (Fe(CO)5), (TB-5-11)-]2,500b 19287-45-7Diborane2,500b 26471-62-5Toluene diisocyanate (unspecified isomer) [Benzene, 1,3-diisocyanatomethyl-1] 110,000a

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 Acetaldehyde75-07-010,000g Acetylene [Ethyne]74-86-210,000f Bromotrifluorethylene [Ethene, bromotrifluoro-]598-73-210,000f 1,3-Butadiene106-99-010,000f Butane106-97-810,000f 1-Butene106-98-910,000f 2-Butene107-01-710,000f Butene25167-67-310,000f 2-Butene-cis590-18-110,000f 2-Butene-trans [2-Butene, (E)]624-64-610,000f Carbon oxysulfide [Carbon oxide sulfide (COS)]463-58-110,000f Chlorine monoxide [Chlorine oxide]7791-21-110,000f 2-Chloropropylene [1-Propene, 2-chloro-]557-98-210,000g 1-Chloropropylene [1-Propene, 1-chloro-]590-21-610,000g Cyanogen [Ethanedinitrile]460-19-510,000f Cyclopropane75-19-410,000f Dichlorosilane [Silane, dichloro-]4109-96-010,000f Difluoroethane [Ethane, 1,1-difluoro-]75-37-610,000f Dimethylamine [Methanamine, N-methyl-]124-40-310,000f 2,2-Dimethylpropane [Propane, 2,2-dimethyl-]463-82-110,000f Ethane74-84-010,000f Ethyl acetylene [1-Butyne]107-00-610,000f Ethylamine [Ethanamine]75-04-710,000f Ethyl chloride [Ethane, chloro-]75-00-310,000f Ethylene [Ethene]74-85-110,000f Ethyl ether [Ethane, 1,1′-oxybis-]60-29-710,000g Ethyl mercaptan [Ethanethiol]75-08-110,000g Ethyl nitrite [Nitrous acid, ethyl ester]109-95-510,000f Hydrogen1333-74-010,000f Isobutane [Propane, 2-methyl]75-28-510,000f Isopentane [Butane, 2-methyl-]78-78-410,000g Isoprene [1,3-Butadinene, 2-methyl-]78-79-510,000g Isopropylamine [2-Propanamine]75-31-010,000g Isopropyl chloride [Propane, 2-chloro-]75-29-610,000g Methane74-82-810,000f Methylamine [Methanamine]74-89-510,000f 3-Methyl-1-butene563-45-110,000f 2-Methyl-1-butene563-46-210,000g Methyl ether [Methane, oxybis-]115-10-610,000f Methyl formate [Formic acid, methyl ester]107-31-310,000g 2-Methylpropene [1-Propene, 2-methyl-]115-11-710,000f 1,3-Pentadinene504-60-910,000f Pentane109-66-010,000g 1-Pentene109-67-110,000g 2-Pentene, (E)-646-04-810,000g 2-Pentene, (Z)-627-20-310,000g Propadiene [1,2-Propadiene]463-49-010,000f Propane74-98-610,000f Propylene [1-Propene]115-07-110,000f Propyne [1-Propyne]74-99-710,000f Silane7803-62-510,000f Tetrafluoroethylene [Ethene, tetrafluoro-]116-14-310,000f Tetramethylsilane [Silane, tetramethyl-]75-76-310,000g Trichlorosilane [Silane, trichloro-]10025-78-210,000g Trifluorochloroethylene [Ethene, chlorotrifluoro-]79-38-910,000f Trimethylamine [Methanamine, N,N-dimethyl-]75-50-310,000f Vinyl acetylene [1-Buten-3-yne]689-97-410,000f Vinyl chloride [Ethene, chloro-]75-01-410,000a, f Vinyl ethyl ether [Ethene, ethoxy-]109-92-210,000g Vinyl fluoride [Ethene, fluoro-]75-02-510,000f Vinylidene chloride [Ethene, 1,1-dichloro-]75-35-410,000g Vinylidene fluoride [Ethene, 1,1-difluoro-]75-38-710,000f Vinyl methyl ether [Ethene, methoxy-]107-25-510,000f

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 60-29-7Ethyl ether [Ethane, 1,1′-oxybis-]10,000g 74-82-8Methane10,000f 74-84-0Ethane10,000f 74-85-1Ethylene [Ethene]10,000f 74-86-2Acetylene [Ethyne]10,000f 74-89-5Methylamine [Methanamine]10,000f 74-98-6Propane10,000f 74-99-7Propyne [1-Propyne]10,000f 75-00-3Ethyl chloride [Ethane, chloro-]10,000f 75-01-4Vinyl chloride [Ethene, chloro-]10,000a, f 75-02-5Vinyl fluoride [Ethene, fluoro-]10,000f 75-04-7Ethylamine [Ethanamine]10,000f 75-07-0Acetaldehyde10,000g 75-08-1Ethyl mercaptan [Ethanethiol]10,000g 75-19-4Cyclopropane10,000f 75-28-5Isobutane [Propane, 2-methyl]10,000f 75-29-6Isopropyl chloride [Propane, 2-chloro-]10,000g 75-31-0Isopropylamine [2-Propanamine]10,000g 75-35-4Vinylidene chloride [Ethene, 1,1-dichloro-]10,000g 75-37-6Difluoroethane [Ethane, 1,1-difluoro-]10,000f 75-38-7Vinylidene fluoride [Ethene, 1,1-difluoro-]10,000f 75-50-3Trimethylamine [Methanamine, N, N-dimethyl-]10,000f 75-76-3Tetramethylsilane [Silane, tetramethyl-]10,000g 78-78-4Isopentane [Butane, 2-methyl-]10,000g 78-79-5Isoprene [1,3,-Butadiene, 2-methyl-]10,000g 79-38-9Trifluorochloroethylene [Ethene, chlorotrifluoro-]10,000f 106-97-8Butane10,000f 106-98-91-Butene10,000f 106-99-01,3-Butadiene10,000f 107-00-6Ethyl acetylene [1-Butyne]10,000f 107-01-72-Butene10,000f 107-25-5Vinyl methyl ether [Ethene, methoxy-]10,000f 107-31-3Methyl formate [Formic acid, methyl ester]10,000g 109-66-0Pentane10,000g 109-67-11-Pentene10,000g 109-92-2Vinyl ethyl ether [Ethene, ethoxy-]10,000g 109-95-5Ethyl nitrite [Nitrous acid, ethyl ester]10,000f 115-07-1Propylene [1-Propene]10,000f 115-10-6Methyl ether [Methane, oxybis-]10,000f 115-11-72-Methylpropene [1-Propene, 2-methyl-]10,000f 116-14-3Tetrafluoroethylene [Ethene, tetrafluoro-]10,000f 124-40-3Dimethylamine [Methanamine, N-methyl-]10,000f 460-19-5Cyanogen [Ethanedinitrile]10,000f 463-49-0Propadiene [1,2-Propadiene]10,000f 463-58-1Carbon oxysulfide [Carbon oxide sulfide (COS)]10,000f 463-82-12,2-Dimethylpropane [Propane, 2,2-dimethyl-]10,000f 504-60-91,3-Pentadiene10,000f 557-98-22-Chloropropylene [1-Propene, 2-chloro-]10,000g 563-45-13-Methyl-1-butene10,000f 563-46-22-Methyl-1-butene10,000g 590-18-12-Butene-cis10,000f 590-21-61-Chloropropylene [1-Propene, 1-chloro-]10,000g 598-73-2Bromotrifluorethylene [Ethene, bromotrifluoro-]10,000f 624-64-62-Butene-trans [2-Butene, (E)]10,000f 627-20-32-Pentene, (Z)-10,000g 646-04-82-Pentene, (E)-10,000g 689-97-4Vinyl acetylene [1-Buten-3-yne]10,000f 1333-74-0Hydrogen10,000f 4109-96-0Dichlorosilane [Silane, dichloro-]10,000f 7791-21-1Chlorine monoxide [Chlorine oxide]10,000f 7803-62-5Silane10,000f 10025-78-2Trichlorosilane [Silane, trichloro-]10,000g 25167-67-3Butene10,000f

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]