Regulations last checked for updates: May 16, 2024

Title 40 - Protection of Environment last revised: May 14, 2024
Appendix - Table 2 to Subpart JJ of Part 63—List of Volatile Hazardous Air Pollutants
Chemical name CAS No.
Acetaldehyde75070
Acetamide60355
Acetonitrile75058
Acetophenone98862
2-Acetylaminofluorine53963
Acrolein107028
Acrylamide79061
Acrylic acid79107
Acrylonitrile107131
Allyl chloride107051
4-Aminobiphenyl92671
Aniline62533
o-Anisidine90040
Benzene71432
Benzidine92875
Benzotrichloride98077
Benzyl chloride100447
Biphenyl92524
Bis (2-ethylhexyl) phthalate (DEHP)117817
Bis (chloromethyl) ether542881
Bromoform75252
1,3-Butadiene106990
Carbon disulfide75150
Carbon tetrachloride56235
Carbonyl sulfide463581
Catechol120809
Chloroacetic acid79118
2-Chloroacetophenone532274
Chlorobenzene108907
Chloroform67663
Chloromethyl methyl ether107302
Chloroprene126998
Cresols (isomers and mixture)1319773
o-Cresol95487
m-Cresol108394
p-Cresol106445
Cumene98828
2,4-D (2,4-Dichlorophenoxyacetic acid, including salts and esters)94757
DDE (1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene)72559
Diazomethane334883
Dibenzofuran132649
1,2-Dibromo-3-chloropropane96128
Dibutylphthalate84742
1,4-Dichlorobenzene106467
3,3′-Dichlorobenzidine91941
Dichloroethyl ether (Bis(2-chloroethyl)ether)111444
1,3-Dichloropropene542756
Diethanolamine111422
N,N-Dimethylaniline121697
Diethyl sulfate64675
3,3′-Dimethoxybenzidine119904
4-Dimethylaminoazobenzene60117
3,3′-Dimethylbenzidine119937
Dimethylcarbamoyl chloride79447
N,N-Dimethylformamide68122
1,1-Dimethylhydrazine57147
Dimethyl phthalate131113
Dimethyl sulfate77781
4,6-Dinitro-o-cresol, and salts534521
2,4-Dinitrophenol51285
2,4-Dinitrotoluene121142
1,4-Dioxane (1,4-Diethyleneoxide)123911
1,2-Diphenylhydrazine122667
Epichlorohydrin (1-Chloro-2,3-epoxypropane)106898
1,2-Epoxybutane106887
Ethyl acrylate140885
Ethylbenzene100414
Ethyl carbamate (Urethane)51796
Ethyl chloride (Chloroethane)75003
Ethylene dibromide (Dibromoethane)106934
Ethylene dichloride (1,2-Dichloroethane)107062
Ethylene glycol107211
Ethylene oxide75218
Ethylenethiourea96457
Ethylidene dichloride (1,1-Dichloroethane)75343
Formaldehyde50000
Glycolethers a
Hexachlorobenzene118741
Hexachloro-1,3-butadiene87683
Hexachloroethane67721
Hexamethylene-1,6-diisocyanate822060
Hexamethylphosphoramide680319
Hexane110543
Hydrazine302012
Hydroquinone123319
Isophorone78591
Maleic anhydride108316
Methanol67561
Methyl bromide (Bromomethane)74839
Methyl chloride (Chloromethane)74873
Methyl chloroform (1,1,1-Trichloroethane)71556
Methyl ethyl ketone (2-Butanone)78933
Methylhydrazine60344
Methyl iodide (Iodomethane)74884
Methyl isobutyl ketone (Hexone)108101
Methyl isocyanate624839
Methyl methacrylate80626
Methyl tert-butyl ether1634044
4,4′-Methylenebis (2-chloroaniline)101144
Methylene chloride (Dichloromethane)75092
4,4′-Methylenediphenyl diisocyanate (MDI)101688
4,4′-Methylenedianiline101779
Naphthalene91203
Nitrobenzene98953
4-Nitrobiphenyl92933
4-Nitrophenol100027
2-Nitropropane79469
N-Nitroso-N-methylurea684935
N-Nitrosodimethylamine62759
N-Nitrosomorpholine59892
Phenol108952
p-Phenylenediamine106503
Phosgene75445
Phthalic anhydride85449
Polychlorinated biphenyls (Aroclors)1336363
Polycyclic Organic Matter b
1,3-Propane sultone1120714
beta-Propiolactone57578
Propionaldehyde123386
Propoxur (Baygon)114261
Propylene dichloride (1,2-Dichloropropane)78875
Propylene oxide75569
1,2-Propylenimine (2-Methyl aziridine)75558
Quinone106514
Styrene100425
Styrene oxide96093
2,3,7,8-Tetrachlorodibenzo-p-dioxin1746016
1,1,2,2-Tetrachloroethane79345
Tetrachloroethylene (Perchloroethylene)127184
Toluene108883
2,4-Toluenediamine95807
Toluene-2,4-diisocyanate584849
o-Toluidine95534
1,2,4-Trichlorobenzene120821
1,1,2-Trichloroethane79005
Trichloroethylene79016
2,4,5-Trichlorophenol95954
2,4,6-Trichlorophenol88062
Triethylamine121448
Trifluralin1582098
2,2,4-Trimethylpentane540841
Vinyl acetate108054
Vinyl bromide593602
Vinyl chloride75014
Vinylidene chloride (1,1-Dichloroethylene)75354
Xylenes (isomers and mixture)1330207
o-Xylene95476
m-Xylene108383
p-Xylene106423

a Includes mono- and di-ethers of ethylene glycol, diethylene glycols and triethylene glycol; R-(OCH2CH2) RR-OR where:

n = 1, 2, or 3,

R = alkyl or aryl groups

R′= R, H, or groups which, when removed, yield glycol ethers with the structure: R-(OCH2CH2)n—OH. Polymers are excluded from the glycol category.

b Includes organic compounds with more than one benzene ring, and which have a boiling point greater than or equal to 100°C.

[63 FR 71381, Dec. 28, 1998]
authority: 42 U.S.C. 7401
source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.