Toxic Air Contaminant (TAC) Identification List
December 1999

This page last reviewed on August 31, 2005.

Toxic Air Contaminant (TAC) Identification List

December 1999

Substance By Category

Click on the ++ to view its chemical summary from the Office of Environmental Health Hazard and Assessment website.

Category I

Category IIa

Category IIb

Category IIIa / b

Category IVa

Category IVb

Category V

Category VI


Category I

Substances identified as Toxic Air Contaminants, known to be emitted in California, with a full set of
health values reviewed by the Scientific Review Panel.

Click on a substance name to view its fact sheet from the 1997 Toxic Air Contaminant Identification List Summaries.
Please note some of the health values have changed since 1997.

Click on the ++ to view its chemical summary from the Office of Environmental Health Hazard
and Assessment website.

Substance

CAS
Number

Cancer
Potency
Value

Chronic
Reference
Exposure Level

Acute Reference
Exposure Level

*

Perchloroethylene (Tetrachloroethylene)

127-18-4

++

++

++

  (There is a potential for 12 substances to move into this category after the SRP has reviewed the noncancer chronic Reference Exposure Levels being developed under the Air Toxics "Hot Spots" Program.)        

Category IIa

Substances identified as Toxic Air Contaminants, known to be emitted in California, with one or more
health values under development by the Office of Environmental Health Hazard Assessment for
review by the Scientific Review Panel.

Click on a substance name to view its fact sheet from the 1997 Toxic Air Contaminant Identification List Summaries.
Please note some of the health values have changed since 1997.

Click on the ++ to view its chemical summary from the Office of Environmental Health Hazard
and Assessment website.

Substance

CAS
Number

Cancer
Potency
Value
(Note 1)

Chronic
Reference
Exposure Level
(Note 2)

Acute Reference
Exposure Level
(Note 3)

  Acetaldehyde

75-07-0

++

++

Limited Data Available

  Acetamide

60-35-5

++

Limited Data Available

Limited Data Available

+

Acrolein

107-02-8

i (Note 1)

X

++

  Acrylamide

79-06-1

++

X

Limited Data Available

  Acrylic Acid

79-10-7

ii (Note 1)

X

++

  Acrylonitrile

107-13-1

++

X

Limited Data Available

  Allyl Chloride

107-05-1

++

X

Limited Data Available

  Aniline

62-53-3

++

X

Limited Data Available

  Antimony and Compounds (Note 4)

7440-36-0

ii (Note 1)

Limited Data Available

Limited Data Available

       Antimony Trioxide

1309-64-4

i (Note 1)

X

Limited Data Available

*+

Inorganic Arsenic and Arsenic Compounds
(Inoganic Including Arsine) (Note 4)

7440-38-2

++

X

++

       Arsine

7784-42-1

ii (Note 1)

X

++

*

Asbestos [Asbestiform Varieties of Serpentine (Chrysotile), Riebeckite (Crocidolite), Cummingtonite-Grunerite (Amosite), Tremolite, Actinolite, and Anthophyllite]

1332-21-4

++

Limited Data Available

Limited Data Available

*

Benzene (Including Benzene from Gasoline)

71-43-2

++

X

++

  Benzyl Chloride

100-44-7

++

Limited Data Available

++

  Beryllium and Compounds (Note 4)

7440-41-7

++

X

Limited Data Available

  Bis(Chloromethyl)Ether

542-88-1

++

Limited Data Available

Limited Data Available

  Bis(2-Ethylhexyl)Phthalate (DEHP)

117-81-7

++

X

Limited Data Available

*

1,3-Butadiene

106-99-0

++

X

Limited Data Available

*

Cadmium and Compounds (Note 4)
(Metallic Cadmium and Cadmium Compounds)

7440-43-9

++

X

Limited Data Available

  Carbon Disulfide

75-15-0

ii (Note 1)

X

++

*

Carbon Tetrachloride (Tetrachloromethane)

56-23-5

++

X

++

*

Chlorinated Dibenzo-P-Dioxins (Note 5)

N/A

++

X

Limited Data Available

       2,3,7,8-Tetrachlorodibenzo-P-Dioxin

1746-01-6

++

X

Limited Data Available

    International Toxicity Equivalency Factors:        
       1,2,3,4,6,7,8-Heptachlorodibenzo-P-Dioxin

35822-46-9

++

X

Limited Data Available

       1,2,3,4,7,8-Hexachlorodibenzo-P-Dioxin

39227-28-6

++

X

Limited Data Available

       1,2,3,6,7,8-Hexachlorodibenzo-P-Dioxin

57653-85-7

++

X

Limited Data Available

       1,2,3,7,8,9-Hexachlorodibenzo-P-Dioxin

19408-74-3

++

X

Limited Data Available

       1,2,3,4,6,7,8,9-Octachlorodibenzo-P-Dioxin

3268-87-9

++

X

Limited Data Available

       1,2,3,7,8-Pentachlorodibenzo-P-Dioxin

40321-76-4

++

X

Limited Data Available

*

Chlorinated Dibenzofurans (Note 5)

N/A

++

X

Limited Data Available

 

  International Toxicity Equivalency Factors:        
       2,3,7,8-Tetrachlorodibenzofuran

5120-73-19

++

X

Limited Data Available

       1,2,3,4,7,8-Hexachlorodibenzofuran

70648-26-9

++

X

Limited Data Available

       1,2,3,6,7,8-Hexachlorodibenzofuran

57117-44-9

++

X

Limited Data Available

       1,2,3,7,8,9-Hexachlorodibenzofuran

72918-21-9

++

X

Limited Data Available

       2,3,4,6,7,8-Hexachlorodibenzofuran

60851-34-5

++

X

Limited Data Available

       1,2,3,4,6,7,8-Heptachlorodibenzofuran

67562-39-4

++

X

Limited Data Available

       1,2,3,4,7,8,9-Heptachlorodibenzofuran

55673-89-7

++

X

Limited Data Available

       1,2,3,4,6,7,8,9-Octachlorodibenzofuran

39001-02-0

++

X

Limited Data Available

       1,2,3,7,8-Pentachlorodibenzofuran

57117-41-6

++

X

Limited Data Available

       2,3,4,7,8-Pentachlorodibenzofuran

57117-31-4

++

X

Limited Data Available

+

Chlorine

7782-50-5

ii (Note 1)

X

++

  Chlorobenzene

108-90-7

ii (Note 1)

X

Limited Data Available

*

Chloroform

67-66-3

++

X

++

+

Chromium and Compounds (Note 4)

7440-47-3

ii (Note 1)

Limited Data Available

Limited Data Available

*

Chromium (VI)

18540-29-9

++

X

Limited Data Available

  Cobalt and Compounds (Note 4)

7440-48-4

i (Note 1)

X

Limited Data Available

  Cresols / Cresylic Acid (Isomers and Mixture)

1319-77-3

ii (Note 1)

X

Limited Data Available

+

Cyanide Compounds (Notes 4 and 11)

57-12-5

ii (Note 1)

Limited Data Available

++

+

1,4-Dichlorobenzene

106-46-7

++

X

Limited Data Available

  3,3-Dichlorobenzidene

91-94-1

++

Limited Data Available

Limited Data Available

  Diethanolamine

111-42-2

ii (Note 1 and 6)

X

Limited Data Available

  Dimethyl Formamide

68-12-2

ii (Note 1)

X

Limited Data Available

  1,4-Dioxane (1,4-Diethyleneoxide)

123-91-1

++

X

++

  Epichlorohydrin (1-Chloro-2,3-Epoxypropane)

106-89-8

++

X

++

  1,2-Epoxybutane

106-88-7

i (Note 1)

X

Limited Data Available

  Ethyl Benzene

100-41-4

ii (Note 1)

X

Limited Data Available

  Ethyl Carbamate (Urethane)

51-79-6

++

Limited Data Available

Limited Data Available

  Ethyl Chloride (Chloroethane)

75-00-3

ii (Note 1)

X

Limited Data Available

*

Ethylene Dibromide (1,2-Dibromoethane)

106-93-4

++

X

Limited Data Available

*

Ethylene Dichloride (1,2-Dichloroethane)

107-06-2

++

X

Limited Data Available

  Ethylene Glycol

107-21-1

ii (Note 1)

X

Limited Data Available

*+

Ethylene Oxide (1,2-Epoxyethane)

75-21-8

++

X

Limited Data Available

  Ethylene Thiourea

96-45-7

++

X

Limited Data Available

  Ethylidene Dichloride (1,1-Dichloroethane)

75-34-3

++

Limited Data Available

Limited Data Available

*+

Formaldehyde

50-00-0

++

X

++

  Glycol Ethers (Note 4 and 7)

N/A

ii (Note 1)

X

++

+

     Ethylene Glycol Monobutyl Ether

111-76-2

ii (Note 1)

X

++

       Ethylene Glycol Monoethyl Ether

110-80-5

ii (Note 1)

X

++

       Ethylene Glycol Monoethyl Ether Acetate

111-15-9

ii (Note 1)

X

++

       Ethylene Glycol Monomethyl Ether

109-86-4

ii (Note 1)

X

++

       Ethylene Glycol Monomethyl Ether Acetate

110-49-6

ii (Note 1)

X

Limited Data Available

  Hexachlorobenzene

118-74-1

++

X

Limited Data Available

  Hexachloroethane

67-72-1

i (Note 1)

X

Limited Data Available

  Hexamethylene-1,6-diisocyanate

822-06-0

ii (Note 1)

X

Limited Data Available

  Hexane

110-54-3

ii (Note 1)

X

Limited Data Available

  Hydrazine

302-01-2

++

X

Limited Data Available

+

Hydrochloric Acid

7647-01-0

ii (Note 1)

X

++

  Hydrogen Aluoride (Hydrofluoric Acid)

7664-39-3

ii (Note 1)

X

++

  Isophorone

78-59-1

i (Note 1)

X

Limited Data Available

*

Inorganic Lead and Inorganic Lead Compounds
(Includes Elemental Lead) (Note 4)

N/A

++

Limited Data Available
(Note 8)

Limited Data Available

  Lead Compounds (Does Not Include
Elemental Lead) (Note 4)

7439-92-1

i (Note 1)

Limited Data Available

Limited Data Available

+

Lindane

58-89-9

++

X

Limited Data Available

  Maleic Anhydride

108-31-6

ii (Note 1)

X

Limited Data Available

+

Manganese and Compounds (Note 4)

7439-96-5

ii (Note 1)

X

Limited Data Available

  Mercury and Compounds (Note 4)

7439-97-6

ii (Note 1)

X

++

       Mercuric Chloride

 7487-94-7

i (Note 1)

Limited Data Available

Limited Data Available

+

Methanol

67-56-1

ii (Note 1)

X

++

+

Methyl Bromide (Bromomethane)

74-83-9

ii (Note 1)

X

++

  Methyl Chloroform (1,1,1-Trichloroethane)

71-55-6

ii (Note 1)

X

++

  Methyl Ethyl Ketone (2-Butanone)

78-93-3

ii (Note 1)

X

++

  Methyl Isocyanate

624-83-9

ii (Note 1)

X

Limited Data Available

  Methyl Methacrylate

80-62-6

iii (Note 1)

X

Limited Data Available

0

Methyl Tertiary Butyl Ether

1634-04-4

++

(Note 15)

Limited Data Available

  4,4-Methylene Bis(2-Chloroaniline)

101-14-4

++

Limited Data Available

Limited Data Available

*

Methylene Chloride (Dichloromethane)

75-09-2

++

X

++

  4,4-Methylenedianiline

101-77-9

++

X

Limited Data Available

  Methylene Diphenyl Diisocyanate

101-68-8

ii (Note 1)

X

Limited Data Available

  Naphthalene

91-20-3

ii (Note 1)

X

Limited Data Available

*

Nickel and Compounds (Note 4)
(Metallic Nickel and Inorganic Nickel Compounds)

7440-02-0

++

X

++

  Nitrobenzene

98-95-3

i (Note 1)

X

Limited Data Available

  2-Nitropropane

79-46-9

i (Note 1)

X

Limited Data Available

  N-Nitrosodimethylamine

62-75-9

++

Limited Data Available

Limited Data Available

  N-Nitrosomorpholine

59-89-2

++

Limited Data Available

Limited Data Available

*

Particulate Emissions from Diesel-Fueled Engines

N/A

++

++

Limited Data Available

+

Pentachlorophenol

87-86-5

++

X

Limited Data Available

  Phenol

108-95-2

ii (Note 1)

X

++

  Phosgene

75-44-5

ii (Note 1)

X

++

  Phosphine

7803-51-2

ii (Note 1)

X

Limited Data Available

+

Phosphorus

7723-14-0

ii (Note 1)

X

Limited Data Available

  Phthalic Anhydride

85-44-9

ii (Note 1)

X

Limited Data Available

  Polychlorinated Biphenyls (Aroclors)

1336-36-3

++

Limited Data Available

Limited Data Available

  Polycyclic Organic Matter (Note 9)

 

     
  Polycyclic Aromatic Hydrocarbon (PAH)

 

     
     Including but not limited to:        
  Benzo[a]pyrene (Note 10)

50-32-8

++

Limited Data Available

Limited Data Available

  Potency Equivalency Factors for PAHs and
PAH-Derivatives (Note 10)		        
       Benz[a]anthracene

56-55-3

++

Limited Data Available

No Data
Available

       Benzo[b]fluoranthene

205-99-2

++

Limited Data Available

No Data
Available

       Benzo[j]fluoranthene

205-82-3

++

Limited Data Available

No Data
Available

       Benzo[k]fluoranthene

207-08-9

++

Limited Data Available

No Data
Available

       Chrysene

218-01-9

++

Limited Data Available

No Data
Available

       Dibenz[a,h]acridine

226-36-8

++

Limited Data Available

No Data
Available

       Dibenz[a,j]acridine

224-42-0

++

Limited Data Available

No Data
Available

       Dibenz[a,h]anthracene

53-70-3

++

Limited Data Available

No Data
Available