IRIS

1,1,2,2-Tetrachloroethane

CASRN 79-34-5

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (29 pp, 250 K) last updated: 09/30/2010

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Hepatic 5 x 10-2
(Subchronic)
Increased relative liver weight in rats BMDL1SD : 15
mg/kg-day
300 Medium
Hepatic 2 x 10-2
(Chronic)
Increased relative liver weight in rats BMDL1SD : 15
mg/kg-day
1000 Medium

 


Reference Concentration for Inhalation Exposure (RfC) (PDF) (29 pp, 250 K) last updated: 09/30/2010
Information reviewed but value not estimated.

 

Cancer Assessment

Weight of Evidence for Cancer (PDF) (29 pp, 250 K) last updated: 09/30/2010

WOE Characterization Framework for WOE Characterization
Likely to be carcinogenic to humans Guidelines for Carcinogen Risk Assessment (US EPA, 2005)
Basis:
  • Under the Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005a) 1,1,2,2-tetrachloroethane is "likely to be carcinogenic to humans."
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (29 pp, 250 K)

Oral Slope Factor: 2 x10 -1 per mg/kg-day
Drinking Water Unit Risk: 6 x10 -6 per µg/L
Extrapolation Method: Multistage model with linear extrapolation from the point of departure (LED10).
Tumor site(s): Hepatic
Tumor type(s): hepatocellular carcinomas (NCI, 1978)



Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (29 pp, 250 K)

Information reviewed but value not estimated.

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