Toxic Air Contaminant Identification List
This page last reviewed July 18, 2011
This page provides information
on substances identified as California toxic air contaminants.
Title 17, CCR, § 93000. Substances Identified
As Toxic Air Contaminants.
Each substance identified in this section has been
determined by the State Board to be a toxic air contaminant as defined
in Health and Safety Code section 39655. If the State Board has found
there to be a threshold exposure level below which no significant
adverse health effects are anticipated from exposure to the identified
substance, that level is specified as the threshold determination. If
the Board has found there to be no threshold exposure level below which
no significant adverse health effects are anticipated from exposure to
the identified substance, a determination of "no threshold" is
specified. If the Board has found that there is not sufficient
available scientific evidence to
support the identification of a threshold exposure level, the
"Threshold" column specifies "None identified."
| Substance | Threshold Determination |
| Benzene (C6H6) | None identified |
| Ethylene Dibromide (BrCH2CH2Br; 1,2-dibromoethane) | None identified |
| Ethylene Dichloride (ClCH2CH2Cl; 1,2-dichloroethane) | None identified |
| Hexavalent chromium (Cr (VI)) | None identified |
| Asbestos [asbestiform varieties of serpentine (chrysotile), riebeckite (crocidolite),cummingtonite-grunerite (amosite), tremolite, actinolite, and anthophyllite] | None identified |
| Dibenzo-p-dioxins and Dibenzofurans chlorinated in the 2,3,7 and 8 positions and containing 4,5,6 or 7 chlorine atoms | None identified |
| Cadmium (metallic cadmium and cadmium compounds) | None identified |
| Carbon Tetrachloride(CCl4; tetrachloromethane) | None identified |
| Ethylene Oxide (1,2-epoxyethane) | None identified |
| Methylene Chloride (CH2Cl2; Dichloromethane) | None identified |
| Trichloroethylene (CCl2CHCl; Trichloroethene) | None identified |
| Chloroform (CHCl3) | None identified |
| Vinyl chloride (C2H3Cl; Chloroethylene) | None identified |
| Inorganic Arsenic | None identified |
| Nickel (metallic nickel and inorganic nickel compounds) | None identified |
| Perchloroethylene (C2Cl4; Tetrachloroethylene) | None identified |
| Formaldehyde (HCHO) | None identified |
| 1,3-Butadiene (C4H6) | None identified |
| Inorganic Lead | None identified |
| Particulate Emissions from Diesel-Fueled Engines | None identified |
| Environmental Tobacco Smoke | None identified |
Note: Authority cited: Sections 39600, 39601 and 39662, Health and Safety Code. Reference: Sections 39650, 39660, 39661 and 39662, Health and Safety Code.
HISTORY
- New section filed 9-23-85; effective thirtieth day thereafter
(Register 85, No. 39). For history of former subchapter 7, see
Registers 84, No. 10;
83, No. 2; 81, No. 48; 77,
No. 12; and 74, No. 47.
- Amendment filed 1-14-86; effective thirtieth day thereafter (Register 86, No. 3).
- Amendment filed 2-10-86; effective thirtieth day thereafter (Register 86,
No. 7).
- Amendment filed 10-9-86; effective thirtieth day thereafter (Register 86, No. 43).
- Amendment filed 11-25-86; effective thirtieth day thereafter (Register 86, No. 48).
- Amendment filed 2-23-87; effective thirtieth day thereafter (Register 87, No. 9).
- Amendment filed 10-8-87; operative 11-7-87 (Register 87, No. 43).
- Amendment filed 3-15-88; operative 4-14-88 (Register 88, No. 13).
- Amendment filed 7-22-88; operative 8-21-88 (Register 88, No. 31).
- Amendment adding Methylene Chloride filed 6-7-90; operative 7-7-90 (Register 90, No. 30).
- Amendment adding Trichloroethylene filed 2-27-91; operative 3-29-91 (Register 91, No. 13).
- Amendment adding Vinyl chloride filed 5-10-91; operative 6-9-91 (Register
91, No. 25).
- Editorial correction, including removal of Inorganic arsenic (Register 91, No. 25).
- Amendment adding Chloroform filed 5-10-91; operative 6-9-91 (Register 91, No. 25).
- Amendment adding Inorganic Arsenic filed 6-6-91; operative 7-6-91 (Register
91, No. 26).
- Change without regulatory effect amending Trichloroethylene and adding
Nickel filed 7-14-92 pursuant to
section 100,
title 1, California Code of
Regulations (Register 92, No. 29).
- Amendment adding Perchloroethylene filed 10-2-92; operative 11-1-92 (Register 92, No. 40).
- Amendment adding Formaldehyde filed 3-2-93; operative 4-1-93 (Register 93,
No. 10).
- Amendment adding 1,3-Butadiene filed 4-14-93; operative 5-14-93 (Register
93, No. 16).
- Editorial correction (Register 98, No. 16).
- Amendment adding inorganic lead filed 4-14-98; operative 5-14-98 (Register
98, No. 16).
- Amendment adding "Particulate Emissions from Diesel-Fueled Engines" filed
7-21-99; operative 8-20-99 (Register 99, No. 30).
- Amendment adding "Environmental Tobacco Smoke" filed 1-9-2007; operative 2-
8-2007 (Register 2007, No. 2).
Title 17, CCR, § 93001. Hazardous Air
Pollutants Identified as Toxic Air Contaminants
Each substance listed in this section has been
identified as a hazardous air pollutant pursuant to subsection (b) of
Section 112 of the federal Clean Air Act (42 U.S.C. Section 7412(b))
and has been designated by the State Board to be a toxic air
contaminant pursuant to Health and Safety Code Section 39657.
Substance
Acetaldehyde
Acetamide
Acetonitrile
Acetophenone
2-Acetylaminofluorene
Acrolein
Acrylamide
Acrylic acid
Acrylonitrile
Allyl chloride
4-Aminobiphenyl
Aniline
o-Anisidine
Asbestos
Benzene (including
benzene from gasoline)
Benzidine
Benzotrichloride
Benzyl chloride
Biphenyl
Bis (2-ethylhexyl)
phthalate (DEHP)
Bis (chloromethyl) ether
Bromoform
1,3-Butadiene
Calcium cyanamide
Caprolactam
Captan
Carbaryl
Carbon disulfide
Carbon tetrachloride
Carbonyl sulfide
Catechol
Chloramben
Chlordane
Chlorine
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, salts and esters
DDE
Diazomethane
Dibenzofurans
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
Dimethyl aminoazobenzene
3,3-Dimethyl benzidine
Dimethyl carbamoyl
chloride
Dimethyl formamide
1,1-Dimethyl hydrazine
Dimethyl phthalate
Dimethyl sulfate
4,6-Dinitro-o-cresol,
and 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
Hexane
Hydrazine
Hydrochloric acid
Hydrogen fluoride
(Hydrofluoric acid)
Hydroquinone
Isophorone
Lindane (all isomers)
Maleic anhydride
Methanol
Methoxychlor
Methyl bromide
(Bromomethane)
Methyl chloride
(Chloromethane)
Methyl chloroform
(1,1,1-Trichloroethane)
Methyl ethyl ketone
(2-Butanone)
Methyl hydrazine
Methyl iodide
(Iodomethane)
Methyl isobutyl ketone
(Hexone)
Methyl isocyanate
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
N-Nitrosodimethylamine
N-Nitrosomorpholine
Parathion
Pentachloronitrobenzene
(Quintobenzene)
Pentachlorophenol
Phenol
p-Phenylenediamine
Phosgene
Phosphine
Phosphorus
Phthalic anhydride
Polychlorinated
biphenyls (Aroclors)
1,3-Propane sultone
beta-Propiolactone
Propionaldehyde
Propoxur (Baygon)
Prophylene dichloride
(1,2-Dichloropropane)
Propylene oxide
1,2-Propylenimine
(2-Methylaziridine)
Quinoline
Quinone
Styrene
Styrene oxide
2,3,7,8-Tetrachlorodibenzo-p-dioxin
1,1,2,2-Tetrachloroethane
Tetrachloroethylene
(Perchloroethylene)
Titanium tetrachloride
Toluene
2,4-Toluene diamine
2,4-Toluene diisocyanate
o-Toluidine
Toxaphene (chlorinated
camphene)
1,2,4-Trichlorobenzene
1,1,2-Trichloroethane
Trichloroethylene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Triethylamine
Trifluralin
2,2,4-Trimethylpentane
Vinyl acetate
Vinyl bromide
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 [FN1]
Glycol
ethers [FN2]
Lead Compounds
Manganese Compounds
Mercury Compounds
Fine mineral
fibers [FN3]
Nickel Compounds
Polycyclic Organic
Matter [FN4]
Radionuclides (including
radon) [FN5]
Selenium Compounds
Note: For all listing
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.
[FN1]
X'CN where X = H' or
any other group where a formal dissociation may occur. For example KCN
or Ca(CN) 2
[FN2]
includes mono- and di-ethers of ethylene glycol, diethylene glycol, and
triethylene glycol (R(OCH 2 CH 2)
n -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(OCH2CH)n -OH. Polymers are
excluded from the glycol category.
[FN3]
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.
[FN4]
includes organic compounds with more than one benzene ring, and which
have a boiling point greater than or equal to 100 degrees °C
[FN5]
a type of atom which spontaneously undergoes radioactive decay.
Note:
Authority cited: Sections 39657, 39600, 39601 and 39662, Health and
Safety Code. Reference: Sections 39650, 39655, 39656, 39657, 39658,
39659, 39660, 39661 and 39662, Health and Safety Code.
HISTORY
- New section filed 3-9-94; operative 4-8-94. Submitted to OAL for printing only (Register 94, No. 10).


