Appendix A

Toxic Air Contaminant Identification List

June 1996

I. Substances identified as Toxic Air Contaminants by the Air Resources Board, pursuant to the provisions of AB 1807 and AB 2728 (includes all Hazardous Air Pollutants listed in the Federal Clean Air Act Amendments of 1990).

Acetaldehyde Cresols/Cresylic acid (isomers Ethylidene dichloride

Acetamide and mixtures) (1,1-dichloroethane) Acetonitrile o-Cresol *Formaldehyde

Acetophenone m-Cresol Heptachlor

2-Acetylaminofluorene p-Cresol Hexachlorobenzene

Acrolein Cumene Hexachlorobutadiene

Acrylamide 2,4-D, salts and esters Hexachlorocyclopentadiene

Acrylic acid DDE Hexachloroethane

Acrylonitrile Diazomethane Hexamethylene-1,6-diisocyanate

Allyl chloride Dibenzofurans Hexamethylphosphoramide

4-Aminobiphenyl 1,2-Dibromo-3-chloropropane Hexane

Aniline Dibutylphthalate Hydrazine

o-Anisidine 1,4-Dichlorobenzene(p) Hydrochloric acid

*Asbestos 3,3-Dichlorobenzidene Hydrogen fluoride (hydrofluoric acid)

*Benzene (including benzene Dichloroethyl ether Hydroquinone

from gasoline) [Bis(2-chloroethyl)ether] *Inorganic arsenic

Benzidine 1,3-Dichloropropene Isophorone

Benzotrichloride Dichlorvos Lindane (all isomers)

Benzyl chloride Diethanolamine Maleic anhydride

Biphenyl N,N-Dimethylaniline Methanol

Bis(2-ethylhexyl)phthalate (DEHP) Diethyl sulfate Methoxychlor

Bis(chloromethyl)ether 3,3-Dimethoxybenzidene Methyl bromide (bromomethane) Bromoform Dimethyl aminoazobenzene Methyl chloride (chloromethane)

*1,3-Butadiene 3,3-Dimethyl benzidene Methyl chloroform

*Cadmium (metallic cadmium and Dimethyl carbamoyl chloride (1,1,1-trichloroethane)

cadmium compounds) Dimethyl formamide Methyl ethyl ketone (2-butanone)

Calcium cyanamide 1,1-Dimethyl hydrazine Methyl hydrazine

Caprolactam Dimethyl phthalate Methyl iodide (iodomethane)

Captan Dimethyl sulfate Methyl isobutyl ketone (hexone)

Carbaryl 4,6-Dinitro-o-cresol, and salts Methyl isocyanate

Carbon disulfide 2,4-Dinitrophenol Methyl methacrylate

*Carbon tetrachloride 2,4-Dinitrotoluene Methyl tert butyl ether

Carbonyl sulfide 1,4-Dioxane (1,4-diethyleneoxide) 4,4-Methylene bis(2-chloroaniline)

Catechol 1,2-Diphenylhydrazine *Methylene chloride

Chloramben Epichlorohydrin (dichloromethane)

Chlordane (1-chloro-2,3-epoxypropane) Methylene diphenyl diisocyanate

Chlorine 1,2-Epoxybutane (MDI)

*Chlorinated dioxins and Ethyl acrylate 4,4-Methylenedianiline

dibenzofurans (15 species) Ethyl benzene Naphthalene

Chloroacetic acid Ethyl carbamate (urethane) *Nickel and nickel compounds

2-Chloroacetophenone Ethyl chloride (chloroethane) Nitrobenzene

Chlorobenzene *Ethylene dibromide (dibromoethane) 4-Nitrobiphenyl

Chlorobenzilate *Ethylene dichloride 4-Nitrophenol

*Chloroform (1,2-dichloroethane) 2-Nitropropane

Chloromethyl methyl ether Ethylene glycol N-Nitroso-N-methylurea

Chloroprene Ethylene imine (aziridine) N-Nitrosodimethylamine

*Chromium VI *Ethylene oxide N-Nitrosomorpholine

Ethylene thiourea Parathion

Pentachloronitrobenzene (Quintobenzene) *Trichloroethylene

Pentachlorophenol 2,4,5-Trichlorophenol

Phenol 2,4,6-Trichlorophenol

p-Phenylenediamine Triethylamine

Phosgene Trifluralin

Phosphine 2,2,4-Trimethylpentane

Phosphorus Vinyl acetate

Phthalic anhydride Vinyl bromide

Polychlorinated biphenyls (aroclors) *Vinyl chloride

1,3-Propane sultone Vinylidene chloride beta-Propiolactone (1,1-dichloroethylene) Propionaldehyde Xylenes (isomers and mixture)

Propoxur (Baygon) m-Xylenes

Propylene dichloride (1,2-dichloropropane) o-Xylenes

Propylene oxide p-Xylenes

1,2-Propylenimine (2-methyl aziridine) o Antimony Compounds Quinoline o Arsenic Compounds (inorganic

Quinone including arsine)

Styrene o Beryllium Compounds

Styrene oxide o Cadmium Compounds

2,3,7,8-Tetrachlorodibenzo-p-dioxin o Chromium Compounds

1,1,2,2-Tetrachloroethane o Cobalt Compounds

*Tetrachloroethylene (perchloroethylene) o Coke Oven Emissions

Titanium tetrachloride o Cyanide Compounds¹

Toluene o Glycol Ethers²

2,4-Toluene diamine o Lead Compounds

2,4-Toluene diisocyanate o Manganese Compounds

o-Toluidine o Mercury Compounds

Toxaphene (chlorinated camphene) o Fine Mineral Fibers³

1,2,4-Trichlorobenzene o Nickel Compounds

1,1,2-Trichloroethane o Polycyclic Organic Matter⁴

o Radionuclides (including radon)⁵

o Selenium Compounds

* Substances which have already been identified by the Board as TACs and which have potency numbers developed by the OEHHA and SRP.

II. Substances currently under review or nominated for review for identification as Toxic Air Contaminants.

A. Substances already in the review process.

Diesel exhaust Inorganic lead

B. Substances nominated for review.

Dialkylnitrosamines Environmental Tobacco Smoke

III. Substances which are being evaluated for entry into Category II (IIA or IIB). Factors considered in this evaluation include carcinogenic and noncarcinogenic health effects, emissions and exposure in California.

Aluminum Gasoline vapors

Ammonia Glutaraldehyde

Ammonium nitrate Hexachlorocyclohexanes

Ammonium sulfate Hydrogen sulfide

Barium compounds Isopropyl alcohol

Benzoyl chloride 4,4'-Isopropylidenediphenol

Bis(2-ethylhexyl)adipate Molybdenum trioxide

Bromine compounds (inorganic) n-Butyl alcohol

Butyl acrylate Nitric acid

Butyl benzyl phthalate Nitrilotriacetic acid

Carbon black extracts Peracetic acid

Chlorinated fluorocarbons 2-Phenylphenol

Chlorine dioxide Phosphoric acid

Chlorophenols Propene

Copper compounds sec-Butyl alcohol

Creosotes Silver Compounds

Crystalline silica Sodium hydroxide

Cumene hydroperoxide Sulfuric acid

Cyclohexane Terephthalic acid

Decabromodiphenyl oxide tert-Butyl alcohol

Diaminotoluene (mixed isomers) Thiourea

Dicofol 1,2,4-Trimethylbenzene

Zinc Compounds

Note: 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 X'CN where X=H' or any other group where a formal dissociation may occur. For example,

KCN or Ca(CN)₂

² includes mono- and di-ethers of ethylene glycol, diethylene glycol, and triethylene glycol

(R(OCH₂CH₂)_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.

³ 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.

⁴ includes organic compounds with more than one benzene ring, and which have a boiling point

greater than or equal to 100^o C.

⁵ a type of atom which spontaneously undergoes radioactive decay.