CASRN 103-23-1

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (17 pp, 135 K) last updated: 07/01/1992

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Developmental, Hepatic, Urinary, Musculoskeletal, Other 6 x 10-1 Changes in body weight and liver weight increased liver weight of male and female parents reduced ossification and slightly dilated ureters in fetuses reduced offspring weight gain, total litter weight, and litter size NOAEL : 1.70 x 102
300 Medium


Reference Concentration for Inhalation Exposure (RfC) (PDF) (17 pp, 135 K)
Not assessed under the IRIS Program.


Cancer Assessment

Weight of Evidence for Cancer (PDF) (17 pp, 135 K) last updated: 08/01/1991

WOE Characterization Framework for WOE Characterization
C (Possible human carcinogen) Guidelines for Carcinogen Risk Assessment (US EPA, 1986)
  • Based on an absence of human data and increased incidence of liver tumors in female mice. Except for a positive dominant lethal assay, there was no evidence of genotoxicity; this compound does, however, exhibit structural relationships to other nongenotoxic compounds classified as probable and possible human carcinogens.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (17 pp, 135 K)

Oral Slope Factor: 1.2 x10 -3 per mg/kg-day
Drinking Water Unit Risk: 3.4 x10 -8 per µg/L
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Hepatic
Tumor type(s): Combined hepatocellular adenomas and carcinomas (NTP, 1982)

Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (17 pp, 135 K)

Not Assessed under the IRIS Program.

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