Table 4.

Cancer unit risks and potency factors per μg/m³.

Compound	U.S. EPA	California (OEHHA)
1,3-Butadiene	3.00 × 10−5	1.70 × 10−4
Methylene chloride	4.70 × 10−7	1.00 × 10−6
Chloroform	2.30 × 10−5	5.30 × 10−6
Benzene (high/low for U.S. EPA)	7.8a/2.20 × 10−6	2.90 × 10−5
Carbon tetrachloride	1.50 × 10−5	4.20 × 10−5
Trichloroethylene	NA	2.00 × 10−6
Perchloroethylene	NA	5.90 × 10−6
1,4-Dichlorobenzene	NA	1.10 × 10−5
Formaldehyde	1.30 × 10−5	6.00 × 10−6
Acetaldehyde	2.20 × 10−6	2.70 × 10−6
1,3-dichloropropene	4.00 × 10−6	NA
Ethylene dibromide (central/high for U.S. EPA)	3.00/6.00 × 10−4b	7.10 × 10−5
Ethylene dichloride	2.60 × 10−5	2.10 × 10−5
Vinyl chloride (continuous adult)	4.40 × 10−6	NA
Vinyl chloride (continuous from birth)	8.80 × 10−6c	7.80 × 10−5
BaP (inhalation)	NA	1.10 × 10−3
BaP [oral slope factor (mg/kg/day) – 1]	7.3	12
Dioxin [oral slope factor (pg/kg/day) – 1]	1.00 × 10−3	1.30 × 10−4

NA, not applicable.

^aUsed higher estimate for comparisons.

^bUsed upper-bound estimate for comparisons.

^cUsed continuous from birth for comparisons.