IRIS

1,2,3-Trichloropropane

CASRN 96-18-4

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (33 pp, 283 K) last updated: 09/30/2009

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Hepatic 4 x 10-3 Increased absolute liver weight in male rats BMDL (ADJ): 1.1
mg/kg-day
300 Medium/High

 


Reference Concentration for Inhalation Exposure (RfC) (PDF) (33 pp, 283 K) last updated: 09/30/2009

System RfC (mg/m3) Basis PoD Composite UF Confidence
Respiratory 3 x 10-4 peribronchial lymphoid hyperplasia in male rats BMCL (HEC): 0.90
mg/m3
3000 Low

 

Cancer Assessment

Weight of Evidence for Cancer (PDF) (33 pp, 283 K) last updated: 09/30/2009

WOE Characterization Framework for WOE Characterization
Likely to be carcinogenic to humans Guidelines for Carcinogen Risk Assessment (US EPA, 2005)
Basis:
  • Under the Guidelines for Carcinogenic Risk Assessment (U.S. EPA, 2005), 1,2,3-trichloropropane is "likely to be carcinogenic to humans", based on a statistically significant and dose-related increase in the formation of multiple tumors in both sexes of two species from an NTP (1993) chronic oral bioassay.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (33 pp, 283 K)

Oral Slope Factor: 3 x10 1 per mg/kg-day
Extrapolation Method: Multistage-Weibull model with linear extrapolation from the point of departure (BMDL10).
Tumor site(s): Reproductive, Ocular, Hepatic, Gastrointestinal
Tumor type(s): alimentary system squamous cell neoplasms, liver hepatocellular adenomas or carcinomas, Harderian gland adenomas, uterine/cervix adenomas or carcinomas (NTP, 1993)
Note: ADAF -- EPA has concluded that 1,2,3-trichloropropane is carcinogenic by a mutagenic mode of action. Application of age-dependent adjustment factors (ADAFs) to the oral slope factor is recommended in combination with appropriate exposure data when assessing risk associated with early-life exposure.



Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (33 pp, 283 K)

Not Assessed under the IRIS Program.

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