Texas Commission on Environmental Quality
Hazardous Air Pollutants Reference Table (HAPS-RT) for Air Quality Permits
This document is used to help facilitate the submission of air quality permit application forms for sources subject to Title
40 Code of Federal Regulations Part 63 (40 CFR Part 63).
The Hazardous Air Pollutants (HAPs) list is found in §112(b) of the Federal Clean Air Act and revisions to this list are
found in 40 CFR Part 63, Subpart C.
CAS No.
75070
60355
75058
98862
53963
107028
79061
79107
Pollutant
Acetaldehyde
Acetamide
Acetonitrile
Acetophenone
2-Acetylaminofluorene
Acrolein
Acrylamide
Acrylic acid
CAS No.
79118
532274
108907
510156
67663
107302
126998
1319773
107131
107051
92671
62533
90040
Acrylonitrile
Allyl chloride
4-Aminobiphenyl
Aniline
o-Anisidine
95487
108394
106445
98828
94757
1332214
Asbestos
3547044
71432
334883
92875
98077
100447
92524
117817
542881
Benzene (including benzene from
gasoline)
Benzidine
Benzotrichloride
Benzyl chloride
Biphenyl
Bis (2-ethylhexyl) phthalate (DEHP)
Bis (chloromethyl) ether
75252
106990
156627
133062
63252
75150
Bromoform
1,3-Butadiene
Calcium cyanamide
Captan
Carbaryl
Carbon disulfide
542756
62737
111422
121697
64675
119904
132649
96128
84742
106467
91941
111444
TCEQ - 20169ctbl (APDG 5271v5, Revised 05/14) HAPS Reference Table
This table is for use by facilities subject to air quality permit requirements
and may be revised periodically
Pollutant
Chloroacetic acid
2-Chloroacetophenone
Chlorobenzene
Chlorobenzilate
Chloroform
Chloromethyl methyl ether
Chloroprene
Cresols/Cresylic acid (isomers and
mixture)
o-Cresol
m-Cresol
p-Cresol
Cumene
2,4-D (2,4-Dichlorophenoxyacetic Acid)
(including salts and esters)
DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)
ethylene)
Diazomethane
Dibenzofuran
1,2-Dibromo-3-chloropropane
Dibutylphthalate
1,4-Dichlorobenzene (p)
3,3-Dichlorobenzidene
Dichloroethyl ether
(Bis[2-chloroethyl]ether)
1,3-Dichloropropene
Dichlorvos
Diethanolamine
N,N-Diethyl aniline (N,N-Dimethylaniline)
Diethyl sulfate
3,3-Dimethoxybenzidine
Page 1 of 5
Texas Commission on Environmental Quality
Hazardous Air Pollutants Reference Table (HAPS-RT) for Air Quality Permits
CAS No.
56235
463581
120809
133904
57749
7782505
77781
534521
51285
121142
123911
122667
106898
106887
140885
100414
51796
75003
106934
107062
107211
151564
75218
96457
75343
50000
76448
118741
87683
77474
67721
822060
680319
Pollutant
Carbon tetrachloride
Carbonyl sulfide
Catechol
Chloramben
Chlordane
Chlorine
Dimethyl sulfate
4,6-Dinitro-o-ocresol (including salts)
2,4-Dinitrophenol
2,4-Dinitrotoluene
1,4-Dioxane (1,4-Diethyleneoxide)
1,2-Diphenylhydrazine
Epichlorohydrin
(1-Chloro-2,3-epoxypropane)
1,2-Epoxybutane
Ethyl acrylate
Ethyl benzene
Ethyl carbamate (Urethane)
Ethyl chloride (Chloroethane)
Ethylene dibromide (Dibromoethane)
Ethylene dichloride (1,2-Dichloroethane)
Ethylene glycol
Ethylene imine (Aziridine)
Ethylene oxide
Ethylene thiourea
Ethylidene dichloride
(1,1-Dichloroethane)
Formaldehyde
Heptachlor
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexamethylene-1,6-diisocyanate
Hexamethylphosphoramide
CAS No.
60117
119937
79447
68122
57147
131113
74839
74873
71556
60344
74884
108101
624839
Pollutant
Dimethyl aminoazobenzene
3,3'-Dimethyl benzidine
Dimethyl carbamoyl chloride
Dimethyl formamide
1,1-Dimethyl hydrazine
Dimethyl phthalate
Methyl bromide (Bromomethane)
Methyl chloride (Chloromethane)
Methyl chloroform (1,1,1-Trichloroethane)
Methyl hydrazine
Methyl iodide (Iodomethane)
Methyl isobutyl ketone (Hexone)
Methyl isocyanate
80626
1634044
101144
75092
101688
101779
91203
98953
92933
100027
79469
684935
Methyl methacrylate
Methyl tert butyl ether
4,4-Methylene bis (2-chloroaniline)
Methylene chloride (Dichloromethane)
Methylene diphenyl diisocyanate (MDI)
4,4'-Methylenedianiline
Naphthalene
Nitrobenzene
4-Nitrobiphenyl
4-Nitrophenol
2-Nitropropane
N-Nitroso-N-methylurea
62759
59892
56382
82688
87865
108952
106503
75445
N-Nitrosodimethylamine
N-Nitrosomorpholine
Parathion
Pentachloronitrobenzene (Quintobenzene)
Pentachlorophenol
Phenol
p-Phenylenediamine
Phosgene
TCEQ - 20169ctbl (APDG 5271v5, Revised 05/14) HAPS Reference Table
This table is for use by facilities subject to air quality permit requirements
and may be revised periodically
Page 2 of 5
Texas Commission on Environmental Quality
Hazardous Air Pollutants Reference Table (HAPS-RT) for Air Quality Permits
CAS No.
110543
302012
7647010
7664393
123319
78591
58899
108316
67561
72435
75558
91225
106514
100425
96093
1746016
79345
Pollutant
127184
CAS No.
Hexane
7803512
Hydrazine
7723140
Hydrochloric acid
85449
Hydrogen fluoride (Hydrofluoric acid) 1336363
Hydroquinone
1120714
Isophorone
57578
Lindane (all isomers)
123386
Maleic anhydride
114261
Methanol
78875
Methoxychlor
75569
1,2-Propylenimine (2-Methyl aziridine) 75014
Quinoline
75354
Quinone
1330207
Styrene
95476
Styrene oxide
108383
2,3,7,8-Tetrachlorodibenzo-p-dioxin
106423
1,1,2,2-Tetrachloroethane
Antimony
Compounds
Tetrachloroethylene (Perchloroethylene) Arsenic Compounds
7550450
Titanium tetrachloride
108883
Toluene
95807
2,4-Toluene diamine
584849
95534
2,4-Toluene diisocyanate
o-Toluidine
8001352
Toxaphene (chlorinated camphene)
Beryllium
Compounds
Cadmium
Compounds
Chromium
Compounds
Cobalt Compounds
Coke Oven
Emissions
Cyanide Compounds
Pollutant
Phosphine
Phosphorus
Phthalic anhydride
Polychlorinated biphenyls (Aroclors)
1,3-Propane sultone
beta-Propiolactone
Propionaldehyde
Propoxur (Baygon)
Propylene dichloride (1,2-Dichloropropane)
Propylene oxide
Vinyl chloride
Vinylidene chloride (1,1-Dichloroethylene)
Xylenes (isomers and mixture)
o-Xylenes
m-Xylenes
p-Xylenes
Antimony Compounds
Arsenic Compounds (inorganic including
arsine)
Beryllium Compounds
Cadmium Compounds
Chromium Compounds
Cobalt Compounds
Coke Oven Emissions
Cyanide Compounds 1
1
120821
79005
79016
1,2,4-Trichlorobenzene
1,1,2-Trichloroethane
Trichloroethylene
Glycol ethers2
Lead Compounds
Manganese
Compounds
TCEQ - 20169ctbl (APDG 5271v5, Revised 05/14) HAPS Reference Table
This table is for use by facilities subject to air quality permit requirements
and may be revised periodically
Glycol ethers2
Lead Compounds
Manganese Compounds
Page 3 of 5
Texas Commission on Environmental Quality
Hazardous Air Pollutants Reference Table (HAPS-RT) for Air Quality Permits
CAS No.
95954
88062
121448
1582098
Pollutant
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Triethylamine
Trifluralin
540841
2,2,4-Trimethylpentane
108054
Vinyl acetate
593602
Vinyl bromide
CAS No.
Mercury Compounds
Fine mineral fibers3
Nickel Compounds
Polycyclic Organic
Matter4
Radionuclides
(including radon)5
Selenium
Compounds
Pollutant
Mercury Compounds
Fine mineral fibers 3
Nickel Compounds
Polycyclic Organic Matter 4
Radionuclides (including radon) 5
Selenium Compounds
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
2
3
4
X'CN where X = H' or any other group where a formal dissociation may occur. For example KCN or Ca(CN)2
Glycol ethers include 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; or
R = phenyl or alkyl substituted phenyl;
R′= H or alkyl C7 or less; or
OR′ consisting of carboxylic acid ester, sulfate, phosphate, nitrate, or sulfonate.
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.
Includes organic compounds with more than one benzene ring, and which have a boiling point greater than or equal
to 100 º C.
TCEQ - 20169ctbl (APDG 5271v5, Revised 05/14) HAPS Reference Table
This table is for use by facilities subject to air quality permit requirements
and may be revised periodically
Page 4 of 5
Texas Commission on Environmental Quality
Hazardous Air Pollutants Reference Table (HAPS-RT) for Air Quality Permits
5
A type of atom which spontaneously undergoes radioactive decay.

The substance caprolactam (CAS number 105602) is deleted from the list of hazardous air pollutants
established by 42 U.S.C. 7412(b)(1). [61 FR 30823, June 18, 1996]

The substance methyl ethyl ketone (MEK, 2-Butanone) (CAS Number 78933) is deleted from the list of
hazardous air pollutants established by 42 U.S.C. 7412(b)(1). [70 FR 75059, December 19, 2005]

The substance ethylene glycol monobutyl ether (EGBE, 2-Butoxyethanol) (CAS Number 111762) is deleted
from the list of hazardous air pollutants established by 42 U.S.C. 7412(b)(1). [69 FR 69325, November 29,
2004]

A clerical error led to the inadvertent addition of hydrogen sulfide to the Section 112(b) list of Hazardous Air
Pollutants. However, a Joint Resolution to remove hydrogen sulfide from the Section 112(b)(1) list was
passed by the Senate on August 1, 1991 (Congressional Record page S11799), and the House of
Representatives on November 25, 1991 (Congressional Record pages H11217-H11219). The Joint Resolution
was approved by the President on December 4, 1991. Hydrogen Sulfide is included in Section 112(r) and is
subject to the accidental release provisions. A study (see below) was required under Section 112(n)(5).
Hydrogen Sulfide Air Emissions Associated with the Extraction of Oil and Natural Gas, EPA-453/R-93-045,
NTIS (publication number is PB94-131224, $36.50 hard copy, $17.50 microfiche). National Technical
Information Services (NTIS) 5285 Port Royal Road Springfield, VA 22161 703-487-4650 800-426-4791
703-487-4807 8:30-5:30 EST M-F
TCEQ - 20169ctbl (APDG 5271v5, Revised 05/14) HAPS Reference Table
This table is for use by facilities subject to air quality permit requirements
and may be revised periodically
Page 5 of 5