Hexachloroethane CASRN 67-72-1 | IRIS

IRIS

Hexachloroethane

CASRN 67-72-1 | DTXSID7020689

Toxicological Review (PDF) (200 pp, 1.61 M)
IRIS Summary (PDF) (34 pp, 308 K)

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (34 pp, 308 K) Last Updated: 09/23/2011

System	RfD (mg/kg-day)	Basis	PoD	Composite UF	Confidence
Urinary	7 x 10 ^-4	Atrophy and degeneration of renal tubules	BMDL ₁₀ : 0.728 mg/kg-day	1000	Low/Medium

Reference Concentration for Inhalation Exposure (RfC) (PDF) (34 pp, 308 K) Last Updated: 09/23/2011

System	RfC (mg/m³)	Basis	PoD	Composite UF	Confidence
Nervous	3 x 10 ^-2	Neurotoxicity (tremors and ruffled pelt)	NOAEL (HEC): 83 mg/m³	3000	Low

Cancer Assessment

Weight of Evidence for Cancer (PDF) (34 pp, 308 K) Last Updated: 09/23/2011

WOE Characterization	Framework for WOE Characterization
Likely to be carcinogenic to humans	Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005)

Basis:

Under the U.S. EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005b), HCE is "likely to be carcinogenic to humans" based on evidence of multiple tumor types in both sexes of rats and mice (NTP, 1989 NCI, 1978).
This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (34 pp, 308 K)

Oral Slope Factor: 4 x 10^-2 per mg/kg-day
Drinking Water Unit Risk: 1 x 10^-6 per µg/L
Extrapolation Method: The multistage model with linear extrapolation from the point of departure (LED10).
Tumor site(s): Urinary
Tumor type(s): Renal adenomas and carcinomas (combined) (NTP (1989))