list revised
5/25/94
BAAQMD
Screening Levels of Carcinogenic Contaminants
| Unit Risk | ||||
| Compound | lb/year(a) | g/m3 | Factor | Source |
| Acetaldehyde | 7.20E+01 | 3.70E-07 | 2.70E-06 | 1 |
| Acrylamide | 1.50E-01 | 7.70E-10 | 1.30E-03 | 1,3 |
| Acrylonitrile | 6.70E-01 | 3.40E-09 | 2.90E-04 | 3 |
| Arsenic & arsenic compounds | 2.4E-02* | 1.3E-10* | 3.30E-03 | 2 |
| Asbestos | 3.00E-03 | 1.60E-11 | {1.9E-04/100 fiber/m3) | 2 |
| Benzene | 6.70E+00 | 3.50E-08 | 2.90E-05 | 3 |
| Benzidine and salts | 1.40E-03 | 7.10E-12 | 1.40E-01 | 3 |
| Beryllium | 1.5E-02* | 7.6E-11* | 2.40E-03 | 1 |
| Bis(chloromethyl)ether | 1.50E-02 | 7.70E-11 | 1.30E-02 | 3 |
| 1,3-Butadiene | 1.10E+00 | 5.90E-09 | 1.70E-04 | 1 |
| Cadmium and cadmium compounds | 4.60E-02 | 2.40E-10 | 4.20E-03 | 3 |
| Carbon tetrachloride | 4.60E+00 | 2.40E-08 | 4.20E-05 | 2,3 |
| Chlorinated dibenzodioxins and dibenzofurans (TCDD and TCDF) | 1.2E-06* | 6.2E-15* | 3.80E+01 | 2,3 |
| Chloroform | 3.60E+01 | 1.90E-07 | 5.30E-06 | 2 |
| Chloroprene | 1.50E+03 | 7.70E-06 | 1.30E-07 | 3 |
| Chromium (hexavalent) | 1.40E-03 | 7.10E-12 | 1.40E-01 | 3 |
| Dibromo-3-chloropropane,1,2- (DBCP) | 9.70E-02 | 5.00E-10 | 2.00E-03 | 3 |
| Dichlorobenzene, 1,4- | 6.80E+01 | 9.10E-08 | 1.10E-05 | 3 |
| Dichlorobenzidine, 3,3'- | 5.60E-01 | 2.90E-09 | 3.40E-04 | 3 |
| Diethylhexylphthalate (DEHP) | 8.10E+01 | 4.20E-07 | 2.40E-06 | 3 |
| Dioxane, 1,4- | 2.50E+01 | 1.30E-07 | 7.70E-06 | 3 |
| Epichlorohydrin | 8.30E+00 | 4.30E-08 | 2.30E-05 | 3 |
| Ethylene dibromide (1,2-dibromoethane) | 2.70E+00 | 1.40E-08 | 7.10E-05 | 2,3 |
| Ethylene dichloride (1,2-dichloroethane) | 9.70E+00 | 4.50E-08 | 2.00E-05 | 2,3 |
| Ethylene oxide | 2.10E+00 | 1.10E-08 | 8.80E-05 | 2 |
| Formaldehyde | 3.30E+01 | 1.70E-07 | 6.00E-06 | 2 |
| Hexachlorobenzene | 3.90E-01 | 2.00E-09 | 5.10E-04 | 3 |
| Hexachlorocyclohexanes | 1.80E-01 | 9.10E-10 | 1.10E-03 | 3 |
| Hydrazine | 3.90E-02 | 2.00E-10 | 4.90E-03 | 1 |
| Methylene chloride | 1.90E+02 | 1.00E-06 | 1.00E-06 | 2 |
| Nickel and nickel compounds | 7.30E-01 | 3.80E-09 | 2.60E-04 | 2 |
| N-Nitrosodiethylamine | 1.90E-02 | 1.00E-10 | 1.00E-02 | 3 |
| N-Nitrosodimethylamine | 4.20E-02 | 2.20E-10 | 4.60E-03 | 3 |
| p-Nitrosodiphenylamine | 7.30E+01 | 3.80E-07 | 2.60E-06 | 3 |
| N-Nitrosodi-n-butylamine | 6.20E-02 | 3.20E-10 | 3.10E-03 | 3 |
| N-Nitrosomethylethylamine | 3.10E-02 | 1.60E-10 | 6.30E-03 | 1,3 |
| N-Nitrosodi-n-propylamine | 9.70E-02 | 5.00E-10 | 2.00E-03 | 3 |
| N-Nitrosopyrrolidine | 3.30E-01 | 1.70E-09 | 6.00E-04 | 1,3 |
| PAHs (including but not limited to)*: | ||||
| Benz[a]anthracene | 4.3E-02 | 2.2E-10 | 1.70E-03 | 4 |
| Benzo[b]fluoroanthene | 4.3E-02 | 2.2E-10 | 1.70E-03 | 4 |
| Benzo[k]fluoroanthene | 4.3E-02 | 2.2E-10 | 1.70E-03 | 4 |
| Benzo[a]pyrene | 4.3E-02 | 2.2E-10 | 1.70E-03 | 4 |
| Dibenz[a,h]anthracene | 4.3E-02 | 2.2E-10 | 1.70E-03 | 4 |
| Indeno[1,2,3-cd]pyrene | 4.3E-02 | 2.2E-10 | 1.70E-03 | 4 |
| PCBs* | 7.0E-03 | 3.6E-11 | 1.40E-03 | 3 |
| Pentachlorophenol | 4.20E+01 | 2.20E-07 | 4.60E-06 | 3 |
| Perchloroethylene (tetrachloroethylene) | 3.30E+01 | 1.70E-07 | 5.90E-06 | 2 |
| Propylene oxide | 5.20E+01 | 2.70E-07 | 3.70E-06 | 1 |
| Trichloroethylene | 9.70E+01 | 5.00E-07 | 2.00E-06 | 2 |
| Trichlorophenol, 2,4,6- | 9.70E+00 | 5.00E-08 | 2.00E-05 | 3 |
| Urethane | 6.60E-01 | 3.40E-09 | 2.90E-04 | 3 |
| Vinyl chloride | 2.50E+00 | 1.30E-08 | 7.80E-05 | 2 |
* screening levels have been adjusted to include the impact from noninhalation pathways
(a) the screening level concentration (g/m3) is the annual concentration
which will result
in a risk of one in one million. 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 concentration = 1-hour concentration = annual concentration x
10
(25'h x 40'w x 40'l)
u = wind speed = 2 m/sec lb/year = annual concentration x 10 x 1.932E+07
Sources for carcinogen screening levels:
1. California-EPA Office of Environmental Health Hazard Assessment, CAPCOA Air Toxics "Hot Spots" Program Risk Assessment Guidelines, October 1993, IRIS database.
2. California-EPA Office of Environmental Health Hazard Assessment, CAPCOA Air Toxics "Hot Spots" Program Risk Assessment Guidelines, October 1993, OEHHA and ARB Toxic Air Contaminant identification document.
3. California-EPA Office of Environmental Health Hazard Assessment, CAPCOA Air Toxics "Hot Spots" Program Risk Assessment Guidelines, October 1993, OEHHA and RCHAS report for implementation of Proposition 65.
4. USEPA, Health Effects Document for Benzo[a]pyrene. EPA/540/1-86/022, September 1984. NTIS PB86-134335.