list revised
5/6/94

BAAQMD

Screening Levels of Noncarcinogenic Contaminants

Screening Trigger Levels

Compound

 lb/year(a) g/m3

Source

Acrolein

3.90E+00

2.00E-08

2

Allyl chloride

1.93E+02

1.00E-06

2

Ammonia

1.93E+04

1.00E-04

2

Benzyl chloride

2.32E+03

1.20E-05

3

Bromine and compounds

3.28E+02

1.70E-06

3

Butyl alcohol, tert-

1.37E+05

7.10E-04

5

Carbon disulfide

1.43E+04

7.40E-05

5

Chlorine

1.37E+03

7.10E-06

3

Chlorobenzene

1.35E+04

7.00E-05

2

Chlorofluorocarbons

1.35E+05

7.00E-04

2

Chlorophenol, 2-

3.47E+03

1.80E-05

2

Chloropicrin

3.28E+02

1.70E-06

3

Chlorotoluene

2.32E+03

1.20E-05

5

Copper

4.63E+02

2.40E-06

3

Cresol

3.47E+04

1.80E-04

2

Dichloroethylene, 1,1-

see Vinylidine chloride

Diethylaminoethanol

2.12E+04

1.10E-04

5

Dimethylamine

3.86E+02

2.00E-06

2

Dimethyl phthalate

2.32E+03

1.20E-05

5

Dioctyl phthalate

2.32E+03

1.20E-05

5

Ethyl alcohol (ethanol)

8.69E+05

4.50E-03

5

Ethyl acetate

6.56E+05

3.40E-03

5

Ethyl acrylate

9.26E+03

4.80E-05

3

Ethylbenzene

1.93E+05

1.00E-03

2

Ethyl chloride

1.93E+06

1.00E-02

2

Freons

see Chlorofluorocarbons

Gasoline vapors

4.05E+05

2.10E-03

3

Glutaraldehyde

3.28E+02

1.70E-06

3

Glycol ethers:

2-ethoxyethanol (Cellosolve)

3.86E+04

2.00E-04

2

2-ethoxyethanol acetate (Cellosolve Acetate)

1.24E+04

6.40E-05

3

2-methoxymethanol (Methylcellosolve)

3.86E+03

2.00E-05

2

2-methoxymethanol acetate (Methylcellosolve Acetate)

1.10E+04

5.70E-05

3

2-butoxyethanol (Butylcellosolve)

3.86E+03

2.00E-05

4

Hexachlorocyclopentadiene

4.63E+01

2.40E-07

2,3

Hexane, n-

8.30E+04

4.30E-04

5

Hydrogen bromide

4.63E+03

2.40E-05

3

Hydrogen chloride

1.35E+03

7.00E-06

2

Hydrogen cyanide

1.35E+04

7.00E-05

2

Hydrogen fluoride

1.14E+03

5.90E-06

3

Hydrogen sulfide

8.11E+03

4.20E-05

6

Isocyanates:

methylene-bis-phenyliso-cyanate

1.83E+01

9.50E-08

3

methyl isocyanate

6.95E+01

3.60E-07

3

toluene diisocyanate

1.83E+01

9.50E-08

3

Isophorone

6.56E+04

3.40E-04

5

Isopropyl alcohol

4.44E+05

2.30E-03

5

Lead, inorganic, and compounds*

2.90E+01

1.50E-07

6

Maleic anhydride

4.63E+02

2.40E-06

3

Manganese and compounds

7.70E+01

4.00E-07

2

Mercury and compounds

5.79E+01

3.00E-07

4

Methyl alcohol

1.20E+05

6.20E-04

3

Methyl bromide

1.16E+03

6.00E-06

4

Methyl chloroform (TCA)

6.18E+04

3.20E-04

2

Methylene dianiline & chloride, 4,4'

3.67E+02

1.90E-06

3

Methylethylketone (MEK)

1.49E+05

7.70E-04

1

Methyl mercury

1.93E+02

1.00E-06

2

Methyl methacrylate

1.89E+05

9.80E-04

3

N-Methylpyrrolidone

1.83E+05

9.50E-04

5

Naphthalene

2.70E+02

1.40E-05

4

Nitric Acid

2.34E+03

1.20E-05

5

Nitrobenzene

3.28E+02

1.70E-06

2

Nitropropane, 2-

3.86E+03

2.00E-05

2

Phenol

8.69E+03

4.50E-05

3

Phosgene

1.83E+02

9.50E-07

5

Phosphine

1.93E+03

1.00E-05

2

Phosphoric acid

4.63E+02

2.40E-06

5

Phosphorus (white)

1.39E+01

7.20E-08

2

Phthalic anhydride

1.35E+06

7.00E-03

2

Selenium and compounds

9.65E+01

5.00E-07

3

Silica, respirable, crystalline

2.32E+02

1.20E-06

3

Sodium hydroxide

9.26E+02

4.80E-06

3

Styrene monomer

1.35E+05

7.00E-04

2

Tetrachlorophenols

1.70E+04

8.80E-05

2

Tetrahydrofuran

2.70E+05

1.40E-03

5

Toluene

3.86E+04

2.00E-04

2

Trichlorobenzene, 1,2,4-

1.83E+04

9.50E-05

5

Trichloroethane, 1,1,1-

see Methyl chloroform

Vapam (Na diethyldithio-carbamate)

2.20E+04

1.10E-04

1

Vinylidene chloride

6.18E+03

3.20E-05

2

Xylene

5.79E+04

3.00E-04

4

Zinc and compounds

6.76E+03

3.50E-05

1

(a)the screening level concentration (g/m3) is the annual concentration which will result in a hazard index (expected concentration/acceptable concentration) of one. This concentration is converted to lb/year, for convenience, by use of the EPA downwash equation:

Q = emission rate = concentration x 1.5 x A x u

A = cross-section = 92.7m2
(25'h x 40'w x 40'l)
u = wind speed = 2 m/sec

concentration = 1-hour concentration = annual concentration x 10
lb/year = annual concentration x 10 x 1.932E+07

Sources for noncarcinogen screening levels:

1. Acceptable Daily Intake; EPA Superfund Public Health Evaluation Manual, 1986.

2. California-EPA Office of Environmental Health Hazard Assessment, CAPCOA Air Toxics "Hot Spots" Program Risk Assessment Guidelines, October 1993, IRIS database.

3. California-EPA Office of Environmental Health Hazard Assessment, CAPCOA Air Toxics "Hot Spots" Program Risk Assessment Guidelines, October 1993, TLV/420.

4. California-EPA Office of Environmental Health Hazard Assessment, CAPCA Air Toxics "Hot Spots" Program Risk Assessment Guidelines, October 1993, EPA Health Effects Assessment Summary Tables, Fourth Quarter FY 1991.

5. Threshold Limit Value (TLV)/ Safety factor of 420.

6. California Ambient Air Quality Standard (CAAQS)