General. The following tables provide thresholds for hazardous air pollutants:

(1) Carcinogens:

CAS Number	Chemical Name	Threshold Levels (tons/year)
189-55-9	1, 2, 7, 8-dibenzopyrene	0.005
107-06-2	1, 2-dichloroethane	0.4
78-87-5	1, 2-dichloropropane	0.5
540-73-8	1, 2-dimethylhydrazine	0.004
122-66-7	1, 2-diphenylhydrazine	0.045
106-99-0	1, 3-butadiene	0.035
1120-71-4	1, 3-propane sultone	0.003
106-46-7	1, 4-dichlorobenzene (p)	0.5
123-91-1	1, 4-dioxane (1, 4-diethyleneoxide)	0.5
94-75-7	2, 4-d salts & esters	0.5
95-80-7	2, 4-toluene diamine	0.01
584-84-9	2, 4-toluene diisocyanate	0.05
53-96-3	2-acetylaminofluorene	0.0025
119-90-4	3, 3'-dimethoxybenzidine	0.5
119-93-7	3, 3-dimethyl benzidine	0.004
101-14-4	4, 4'-methylenebis (2-chloroaniline)	0.5
75-07-0	acetaldehyde	0.5
107-13-1	acrylonitrile	0.15
62-53-3	aniline	0.5
C7440-38-2	arsenic and inorganic arsenic compounds	0.002
1332-21-4	asbestos (fibers/ml)	0.00004
71-43-2	benzene	0.5
92-87-5	benzidine (and its salts)	0.00015
56-55-3	benzo(a)anthracene	0.005
50-32-8	benzo(a)pyrene	0.005
205-99-2	benzo(b)fluoranthene	0.005
7440-41-7	beryllium and compounds (except salts)	0.004
117-81-7	bis (2-ethylhexyl) phthalate	0.5
542-88-1	bis (chloromethyl) ether	0.00015
75-25-2	bromoform	0.5
7440-43-9	cadmium and compounds	0.005
56-23-5	carbon tetrachloride	0.5
57-74-9	chlordane	0.005
510-15-6	chlorobenzilate	0.2
67-66-3	chloroform	0.45
107-30-2	chloromethyl methyl ether	0.1
126-99-8	chloroprene	0.5
C7440-47-3	chromium, hexavalent metal	0.001
218-01-9	chrysene	0.005
———	coke oven emissions	0.015
3547-04-4	DDE	0.005
53-70-3	dibenz(a, h)anthracene	0.005
132-64-9	dibenzofuran	0.5
111-44-4	dichloroethyl ether	0.03
75-09-2	dichloromethane	0.5
77-78-1	dimethyl sulfate	0.1
———	dioxins & furans (tcdd equivalent)	3e-07
106-89-8	epichlorohydrin	0.5
107-06-2	ethylene dichloride	0.4
106-93-4	ethylene dibromide (dibromethane)	0.05
75-21-8	ethylene oxide	0.1
96-45-7	ethylene thiourea	0.3
76-44-8	heptachlor	0.01
118-74-1	hexachlorobenzene	0.005
58-89-9	hexachlorocyclohexane, gamma	0.005
302-01-2	hydrazine	0.002
193-39-5	indeno (1, 2, 3-cd) pyrene	0.005
———	lead & compounds (except those listed)	0.005
58-89-9	lindane	0.005
75-09-2	methylene chloride	0.5
62-75-9	n-nitrosodimethylamine	0.0005
C7440-02-0	nickel and compounds (except those listed)	0.02
13463-39-3	nickel carbonyl	0.1
95-53-4	o-toluidine	0.5
87-86-5	pentachlorophenol	0.35
127-18-4	perchloroethylene	0.5
1336-36-3	polychlorinated biphenyls	0.0045
75-56-9	propylene oxide	0.5
8001-35-2	toxaphene	0.005
79-01-6	trichloroethylene	0.5
75-01-4	vinyl chloride	0.1
79-34-5	1, 1, 2, 2-tetrachloroethane	0.15
79-00-5	1, 1, 2-trichloroethane	0.5
57-14-7	1, 1-dimethyl hydrazine	0.004
96-12-8	1, 2-dibromo-3-chloropropane	0.004
79-06-1	acrylamide	0.01
98-07-7	benzotrichloride	0.003
62-73-7	dichlorvos	0.1
79-44-7	dimethyl carbamoyl chloride	0.5
140-88-5	ethyl acrylate	0.5
51-79-6	ethyl carbamate	0.5
151-56-4	ethylene imine	0.5
87-68-3	hexachlorobutadiene	0.5
67-72-1	hexachloroethane	0.5
60-34-4	methyl hydrazine	0.03
684-93-5	n-nitroso-n-methylurea	0.5
12035-72-2	nickel refinery dust	0.08
———	nickel subsulfide	0.02
82-68-8	pentachloronitrobenzene	0.15
91-22-5	quinoline	0.003
1582-09-8	trifluralin	0.5
593-60-2	vinyl bromide	0.5
75-35-4	vinylidene chloride	0.2
189559	1, 2: 7, 8-dibenzopyrene	0.005
121142	2, 4-dinitrotoluene	0.01
88062	2, 4, 6-trichlorophenol	0.5
91941	3, 3-dichlorobenzidene	0.1
57596	7, 12-dimethylbenz(a)anthracene	0.005
50000	formaldehyde	0.5

(2) Noncarcinogens:

CAS Number	Chemical Name	Threshold Levels (tons/year)
75-34-3	ethylidene dichloride (1, 1-dichloroethane)	0.5
75-55-8	1, 2 propylenimine (2-methyl aziridine)	0.003
120-82-1	1, 2, 4-trichlorobenzene	0.5
106-88-7	1, 2-epoxybutane	0.5
542-75-6	1, 3-dichloropropene (dichloropropene)	0.5
51-28-5	2, 4-dinitrophenol	0.5
111-76-2	2-butoxyethanol	0.5
110-80-5	2-ethoxyethanol	0.5
109-86-4	2-methoxyethanol	0.5
92-93-3	4-nitrobiphenol	0.5
100-02-7	4-nitrophenol	0.5
75-05-8	acetonitrile	0.5
98-86-2	acetophenone	0.5
107-02-8	acrolein	0.04
79-10-7	acrylic acid	0.5
107-05-1	allyl chloride	0.5
C7440-36-0	antimony & compounds as sb	0.5
1309-64-4	antimony trioxide, as sb	0.5
7784-42-1	arsine	0.1
100-44-7	benzyl chloride	0.1
92-52-4	biphenyl	0.5
156-62-7	calcium cyanamide	0.5
105-60-2	caprolactam, dust	0.5
105-60-2	caprolactam, vapor	0.5
133-06-2	captan	0.5
63-25-2	carbaryl	0.5
75-15-0	carbon disulfide	0.5
463-58-1	carbonyl sulfide	0.5
120-80-9	catechol	0.5
7782-50-5	chlorine	0.1
79-11-8	chloroacetic acid	0.1
532-27-4	chloroacetophenone, alpha-	0.06
108-90-7	chlorobenzene	0.5
C7440-47-3	chromium (ii) compounds, as cr	0.5
C7440-47-3	chromium (iii) compounds, cr	0.5
10210-68-1	cobalt carbonyl, as co	0.1
7440-48-4	cobalt, as co metal dust, fume	0.1
1319-77-3	cresols/cresylic acid, (isomers and mixture)	0.5
95-48-7	o-cresol	0.5
108-39-4	m-cresol	0.5
106-44-5	p-cresol	0.5
98-82-8	cumene	0.5
51-12-5	cyanides, as cn	0.5
84-74-2	dibutyl phthalate	0.5
111-42-2	diethanolamine	0.5
60-11-7	dimethyl aminoazobenzene	0.5
121-69-7	dimethylaniline	0.5
68-12-2	dimethylformamide	0.5
131-11-3	dimethylphthalate	0.5
100-41-4	ethyl benzene	0.5
75-00-3	ethyl chloride	0.5
107-21-1	ethylene glycol	0.5
111-76-2	ethylene glycol monobutyl ether	0.5
———	glycol ethers (except for listed ones)	0.5
77-47-4	hexachlorocyclopentadiene	0.1
822-06-0	hexamethylene, 1, 6-diisocyanate	0.02
110-54-3	hexane (n-hexane)	0.5
110-54-3	hexane, other isomers	0.5
7647-01-0	hydrogen chloride	0.5
7664-39-3	hydrogen fluoride, as f	0.1
123-31-9	hydroquinone	0.5
78-59-1	isophorone	0.5
108-31-6	maleic anhydride	0.5
C7439-96-5	manganese dust & compounds (except listed)	0.5
748-79-4	mercuric chloride	0.01
10045-94-0	mercuric nitrate	0.01
C7439-97-6	mercury, elemental	0.01
72-43-5	methoxychlor	0.5
67-56-1	methyl alcohol	0.5
74-83-9	methyl bromide	0.5
74-87-3	methyl chloride	0.5
71-55-6	methyl chloroform (1, 1, 1-trichloroethane)	0.5
78-93-3	methyl ethyl ketone (mek)	0.5
74-88-4	methyl iodide	0.06
108-10-1	methyl isobutyl ketone	0.5
624-83-9	methyl isocyanate	0.1
80-62-6	methyl methacrylate	0.5
1634-04-4	methyl tert-butyl ether	0.5
12108-13-3	methylcyclopentadienyl manganese tricarbonyl	0.1
101-68-8	methylene bisphenyl isocyanate	0.1
91-20-3	naphthalene	0.5
98-95-3	nitrobenzene	0.5
106-50-3	p-phenylenediamine	0.5
56-38-2	parathion	0.1
108-95-2	phenol	0.1
62-38-4	phenyl mercuric acetate	0.01
75-44-5	phosgene	0.1
7803-51-2	phosphine	0.5
7723-14-0	phosphorus	0.1
85-44-9	phthalic anhydride	0.5
57-57-8	propiolactone, beta-	0.1
123-38-6	propionaldehyde	0.5
114-26-1	propoxur	0.5
106-51-4	quinone	0.5
C7782-49-2	selenium compounds, as se	0.5
7783-79-1	selenium hexafluoride, as se	0.5
7488-56-4	selenium sulfides (mono and di)	0.5
100-42-5	styrene monomer	0.5
78-00-2	tetraethyl lead, as pb	0.01
75-74-1	tetramethyl lead, as pb	0.01
7550-45-0	titanium tetrachloride	0.1
108-88-3	toluene	0.5
121-44-8	triethylamine	0.5
108-05-4	vinyl acetate	0.5
593-60-2	vinyl bromide	0.5
1330-20-7	xylenes (m-,o-,p-isomers)	0.5
79469	2-nitropropane	0.5
540841	2, 2, 4-trimethylpentane	0.5
95954	2, 4, 5-trichlorophenol	0.5
92671	4-aminobiphenyl	0.5
101779	4, 4'-methlenedianiline	0.5
534521	4, 6-dinitro-o-cresol and salts	0.1
60355	acetamide	0.5
1345046	antimony trisulfide	0.1
7783702	antimony pentafluoride	0.1
28300745	antimony potassium tartrate	0.5
133904	chloramben	0.5
———	chromium compounds, except hexavalent and trivalent	0.5
10025737	chromic chloride	0.1
334883	diazomethane	0.5
64675	diethyl sulfate	0.5
62207765	fluomine	0.1
680319	hexamethylphosphoramide	0.01
12108133	methylcyclopentadienyl manganese	0.1
101688	methylene diphenyl diisocyanate	0.1
69892	N-nitrosomorpholine	0.5
90040	o-anisidine	0.5
———	polycyclic organic matter	0.01
151508	potassium cyanide	0.1
14339	sodium cyanide	0.1
10102188	sodium selenite	0.1
13410010	sodium selenate	0.1
96093	styrene oxide	0.5

PDFWAC 173-401-531

Thresholds for hazardous air pollutants.