Azobenzene

CASRN 103-33-3

  • IRIS Summary (PDF) (9 pp, 97 K)
  • Status: Azobenzene 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, 97 K)
Not assessed under the IRIS Program.

Reference Concentration for Inhalation Exposure (RfC) (PDF) (9 pp, 97 K)
Not assessed under the IRIS Program.

Cancer Assessment


Weight of Evidence for Cancer (PDF) (9 pp, 97 K) last updated: 09/07/1988

WOE Characterization Framework for WOE Characterization
B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals) Guidelines for Carcinogen Risk Assessment (US EPA, 1986)
Basis:
  • Azobenzene induced invasive sarcomas in the spleen and other abdominal organs in male and female F344 rats following dietary administration. It is genotoxic and may be converted to benzidine, a known human carcinogen, under the acidic conditions in the stomach.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (9 pp, 97 K)

Oral Slope Factor: 1.1 x10 -1 per mg/kg-day
Drinking Water Unit Risk: 3.1 x10 -6 per µg/L
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Other
Tumor type(s): Abdominal cavity sarcomas (NCI, 1979)


Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (9 pp, 97 K)

Inhalation Unit Risk: 3.1 x10 -5 per µg/m3
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Other
Tumor type(s): Abdominal cavity sarcomas (NCI, 1979)


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