Toxic Air Contaminant Identification List (June 1996)

This page last reviewed July 30, 2008

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   Hydrazine
  Acetamide   Hydrochloric Acid
  Acetonitrile   Hydrogen Fluoride (Hydrofluoric Acid)
  Acetophenone   Hydroquinone
  2-Acetylaminofluorene   *Inorganic Arsenic
  Acrolein   Isophorone
  Acrylamide   Lindane (All Isomers)
  Acrylic Acid   Maleic Anhydride
  Acrylonitrile   Methanol
  Allyl Chloride   Methoxychlor
  4-Aminobiphenyl   Methyl Bromide (Bromomethane)
  Aniline   Methyl Chloride (Chloromethane)
  O-Anisidine   Methyl Chloroform (1,1,1-Trichloroethane)
  *Asbestos   Methyl Ethyl Ketone (2-Butanone)
  *Benzene (Including Benzene from Gasoline)   Methyl Hydrazine
  Benzidine   Methyl Iodide (Iodomethane)
  Benzotrichloride   Methyl Isobutyl Ketone (Hexone)
  Benzyl Chloride   Methyl Isocyanate
  Biphenyl   Methyl Methacrylate
  Bis(2-Ethylhexyl)Phthalate (DEHP)   Methyl Tert Butyl Ether
  Bis(Chloromethyl)Ether   4,4-Methylene Bis(2-Chloroaniline)
  Bromoform   *Methylene Chloride (Dichloromethane)
  *1,3-Butadiene   Methylene Diphenyl Diisocyanate (MDI)
  *Cadmium (Metallic Cadmium and Cadmium Compounds)   4,4-Methylenedianiline
  Calcium Cyanamide   Naphthalene
  Caprolactam   *Nickel and Nickel Compounds
  Captan   Nitrobenzene
  Carbaryl   4-Nitrobiphenyl
  Carbon Disulfide   4-Nitrophenol
  *Carbon Tetrachloride   2-Nitropropane
  Carbonyl sulfide   N-Nitroso-N-Methylurea
  Catechol   N-Nitrosodimethylamine
  Chloramben   N-Nitrosomorpholine
  Chlordane   Parathion
  Chlorine   Pentachloronitrobenzene (Quintobenzene)
  *Chlorinated Dioxns and Dibenzofurans (15 Species)   Pentachlorophenol
  Chloroacetic Acid   Phenol
  2-Chloroacetophenone   P-Phenylenediamine
  Chlorobenzene   Phosgene
  Chlorobenzilate   Phosphine
  *Chloroform   Phosphorus
  Chloromethyl Methyl Ether   Phthalic Anhydride
  Chloroprene   Polychlorinated Biphenyls (Aroclors)
  *Chromium VI   1,3-Propane Sultone
  Cresols / Cresylic Acid (Isomers and Mixtures)   Beta-Propiolactone
  O-Cresol   Propionaldehyde
  M-Cresol   Propoxur (Baygon)
  P-Cresol   Propylene Dichloride (1,2-Dichloropropane)
  Cumene   Propylene Oxide
  2,4-D, Salts and Esters   1,2-Propylenimine (2-Methyl Aziridine)
  DDE   Quinoline
  Diazomethane   Quinone
  Dibenzofurans   Styrene
  1,2-Dibromo-3-Chloropropane   Styrene Oxide
  Dibutylphthalate   2,3,7,8-Tetrachlorodibenzo-P-Dioxin
  1,4-Dichlorobenzene(p)   1,1,2,2-Tetrachloroethane
  3,3-Dichlorobenzidene   *Tetrachloroethylene (Perchloroethylene)
  Dichloroethyl Ether [Bis(2-Chloroethyl)Ether]   Titanium Tetrachloride
  1,3-Dichloropropene   Toluene
  Dichlorvos   2,4-Toluene Diamine
  Diethanolamine   2,4-Toluene Diisocyanate
  N,N-Dimethylaniline   O-Toluidine
  Diethyl Sulfate   Toxaphene (Chlorinated Camphene)
  3,3-Dimethoxybenzidene   1,2,4-Trichlorobenzene
  Dimethyl Aminoazobenzene   1,1,2-Trichloroethane
  3,3-Dimethyl Benzidene   *Trichloroethylene
  Dimethyl Carbamoyl Chloride   2,4,5-Trichlorophenol
  Dimethyl Formamide   2,4,5-Trichlorophenol
  1,1-Dimethyl Hydrazine   2,4,6-Trichlorophenol
  Dimethyl Phthalate   Triethylamine
  Dimethyl Sulfate   Trifluralin
  4,6-Dinitro-O-Cresol, and Salts   2,2,4-Trimethylpentane
  2,4-Dinitrophenol   Vinyl Acetate
  2,4-Dinitrotoluene   Vinyl Bromide
  1,4-Dioxane (1,4-Diethyleneoxide)   *Vinyl Chloride
  1,2-Diphenylhydrazine   Vinylidene Chloride (1,1-Cichloroethylene)
  Epichlorohydrin (1-Chloro-2,3-Epoxypropane)   Xylenes (Isomers and Mixture)
  1,2-Epoxybutane   M-Xylenes
  Ethyl Acrylate   O-Xylenes
  Ethyl Benzene   P-Xylenes
  Ethyl Carbamate (Urethane)   o Antimony Compounds
  Ethyl Chloride (Chloroethane)   o Arsenic Compounds (Inorganic Including Arsine)
  *Ethylene Dibromide (Dibromoethane)   o Beryllium Compounds
  *Ethylene Dichloride (1,2-Dichloroethane)   o Cadmium Compounds
  Ethylene Glycol   o Chromium Compounds
  Ethylene Imine (Aziridine)   o Cobalt Compounds
  *Ethylene Oxide   o Coke Oven Emissions
  Ethylene Thiourea   o Cyanide Compounds1
  Ethylidene Dichloride (1,1-Dichloroethane)   o Glycol Ethers2
  *Formaldehyde   o Lead Compounds
  Heptachlor   o Manganese Compounds
  Hexachlorobenzene   o Mercury Compounds
  Hexachlorobutadiene   o Fine Mineral Fibers3
  Hexachlorocyclopentadiene   o Nickel Compounds
  Hexachloroethane   o Polycyclic Organic Matter4
  Hexamethylene-1,6-Diisocyanate   o Radionuclides (Including Radon)5
  Hexamethylphosphoramide   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.


AB 1807, Statutes 1983, chapter 1047, Health & Safety Code section 39650 et. seq.
AB 2728, Statutes 1992, chapter 1161, Healthe & Safety Code secitons 39655 et. seq.
II. Substances currently under review or nominated for review for identification as Toxic Air Contaminants.

Substances already in the review process.

    Diesel Exhaust
    Inorganic Lead

Substances nominated for review.

    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   Glutaraldehyde
  Ammonia   Hexachlorocyclohexanes
  Ammonium Nitrate   Hydrogen Sulfide
  Ammonium Sulfate   Isopropyl Alcohol
  Barium Compounds   4,4'-Isopropylidenediphenol
  Benzoyl Chloride   Molybdenum Trioxide
  Bis(2-Ethylhexyl)Adipate   N-Butyl Alcohol
  Bromine Compounds (Inorganic)   Nitric Acid
  Butyl Acrylate   Nitrilotriacetic Acid
  Butyl Benzyl Phthalate   Peracetic Acid
  Carbon Black Extracts   2-Phenylphenol
  Chlorinated Fluorocarbons   Phosphoric Acid
  Chlorine Dioxide   Propene
  Chlorophenols   Sec-Butyl Alcohol
  Copper Compounds   Silver Compounds
  Creosotes   Sodium Hydroxide
  Crystalline Silica   Sulfuric Acid
  Cumene Hydroperoxide   Terephthalic Acid
  Cyclohexane   Tert-Butyl Alcohol
  Decabromodiphenyl oxide   Thiourea
  Diaminotoluene (Mixed Isomers)   1,2,4-Trimethylbenzene
  Dicofol   Zinc Compounds
  Gasoline Vapors    
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.


X'CN where X = H' or any other group where a formal dissociation may occur. For example: KCN or Ca(CN)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.


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 100oC.


A type of atom which spontaneously undergoes radioactive decay.

TAC Fact Sheets
Proposed Update to the TAC List - Draft Staff Report