IRIS

p,p'-Dichlorodiphenyltrichloroethane (DDT)

CASRN 50-29-3

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (17 pp, 133 K) last updated: 03/31/1987

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Hepatic 5 x 10-4 Liver lesions NOEL : 5 x 10-2
mg/kg-day
100 Medium

 


Reference Concentration for Inhalation Exposure (RfC) (PDF) (17 pp, 133 K)
Not assessed under the IRIS Program.

 

Cancer Assessment

Weight of Evidence for Cancer (PDF) (17 pp, 133 K) last updated: 08/22/1988

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:
  • Observation of tumors (generally of the liver) in seven studies in various mouse strains and three studies in rats. DDT is structurally similar to other probable carcinogens, such as DDD and DDE.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (17 pp, 133 K)

Oral Slope Factor: 3.4 x10 -1 per mg/kg-day
Drinking Water Unit Risk: 9.7 x10 -6 per µg/L
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Hepatic
Tumor type(s): Liver tumors, benign and malignant (Turusov et al., 1973; Terracini et al., 1973; Thorpe and Walker, 1973; Tomatis and Turusov, 1975; Cabral et al., 1982; Rossi et al., 1977)



Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (17 pp, 133 K)

Inhalation Unit Risk: 9.7 x10 -5 per µg/m3
Extrapolation Method: Linear multistage procedure, extra risk
Tumor site(s): Hepatic
Tumor type(s): Liver tumors, benign and malignant (Turusov et al., 1973; Terracini et al., 1973; Thorpe and Walker, 1973; Tomatis and Turusov, 1975; Cabral et al., 1982; Rossi et al., 1977)


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