IRIS

Benzidine

CASRN 92-87-5

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (16 pp, 129 K) last updated: 01/01/1989

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Nervous, Hepatic 3 x 10-3 Brain cell vacuolization; liver cell alterations in females LOAEL : 2.7
mg/kg-day
1000 Medium

 


Reference Concentration for Inhalation Exposure (RfC) (PDF) (16 pp, 129 K) last updated: 07/01/1991
Information reviewed but value not estimated.

 

Cancer Assessment

Weight of Evidence for Cancer (PDF) (16 pp, 129 K) last updated: 03/31/1987

WOE Characterization Framework for WOE Characterization
A (Human carcinogen) Guidelines for Carcinogen Risk Assessment (US EPA, 1986)
Basis:
  • Observation of increased incidence of bladder cancer and bladder cancer-related deaths in exposed workers
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (16 pp, 129 K)

Oral Slope Factor: 2.3 x10 2 per mg/kg-day
Drinking Water Unit Risk: 6.7 x10 -3 per µg/L
Extrapolation Method: One-hit with time factor, extra risk
Tumor site(s): Urinary
Tumor type(s): Bladder tumors (Zavon, 1973)



Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (16 pp, 129 K)

Inhalation Unit Risk: 6.7 x10 -2 per µg/m3
Extrapolation Method: One-hit with time factor, extra risk
Tumor site(s): Urinary
Tumor type(s): Bladder tumors (Zavon, 1973)


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