beta-Hexachlorocyclohexane (beta-HCH)

CASRN 319-85-7

  • IRIS Summary (PDF) (9 pp, 98 K)
  • Status: beta-Hexachlorocyclohexane (beta-HCH) is not being reassessed by IRIS at this time.

Health Hazard Assessments for Effects Other than Cancer


Reference Dose for Oral Exposure (RfD) (PDF) (9 pp, 98 K)
Not assessed under the IRIS Program.

Reference Concentration for Inhalation Exposure (RfC) (PDF) (9 pp, 98 K)
Not assessed under the IRIS Program.

Cancer Assessment


Weight of Evidence for Cancer (PDF) (9 pp, 98 K) last updated: 09/30/1987

WOE Characterization Framework for WOE Characterization
C (Possible human carcinogen) Guidelines for Carcinogen Risk Assessment (US EPA, 1986)
Basis:
  • Increases in benign liver tumors in CF1 mice fed beta-HCH
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (9 pp, 98 K)

Oral Slope Factor: 1.8 per mg/kg-day
Drinking Water Unit Risk: 5.3 x10 -5 per µg/L
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Hepatic
Tumor type(s): Hepatic nodules and hepatocellular carcinomas (Thorpe and Walker, 1973)


Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (9 pp, 98 K)

Inhalation Unit Risk: 5.3 x10 -4 per µg/m3
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Hepatic
Tumor type(s): Hepatic nodules and hepatocellular carcinomas (Thorpe and Walker, 1973)


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