IRIS

Trichloroethylene

CASRN 79-01-6

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (63 pp, 520 K) last updated: 09/28/2011

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Immune 5 x 10-4 Decreased thymus weight in female B6C3F1 mice (adult immunological effects) LOAEL (HED99): 0.048
mg/kg-day
100 High
Immune 5 x 10-4 Decreased plaque-forming cell (PFC) response, increased delayed-type hypersensitivity in B6C3F1 mice (development immunotoxicity) LOAEL : 0.37
mg/kg-day
1000 High
Immune 5 x 10-4 Increased fetal cardiac malformations in Sprague-Dawley rats (heart malformations) BMDL01 (HED99): 0.0051
mg/kg-day
10 High

 


Reference Concentration for Inhalation Exposure (RfC) (PDF) (63 pp, 520 K) last updated: 09/28/2011

System RfC (mg/m3) Basis PoD Composite UF Confidence
Immune 2 x 10-3 Decreased thymus weight in female B6C3F1 mice (immunotoxicity) LOAEL (HEC99): 0.19
mg/m3
100 High
Immune 2 x 10-3 Increased fetal cardiac malformations in Sprague-Dawley rats (heart malformations) BMDL01 (HEC99): 0.021
mg/m3
10 High
Immune 2 x 10-3 Increased fetal cardiac malformations in Sprague-Dawley rats (heart malformations) BMDL01 (HEC99): 0.021
mg/m3
10 High

 

Cancer Assessment

Weight of Evidence for Cancer (PDF) (63 pp, 520 K) last updated: 09/28/2011

WOE Characterization Framework for WOE Characterization
Carcinogenic to humans Guidelines for Carcinogen Risk Assessment (US EPA, 2005)
Basis:
  • Following U.S. EPA (2005b) Guidelines for Carcinogen Risk Assessment, TCE is characterized as "carcinogenic to humans" by all routes of exposure.
  • This may be a synopsis of the full weight-of-evidence narrative.

WOE Footnote:  EPA has concluded, by a weight of evidence evaluation, that Trichloroethylene is carcinogenic by a mutagenic mode of action. Age-dependent adjustment factors (ADAFs) should be used when estimating age-specific cancer risks. See IRIS Summary.


Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (63 pp, 520 K)

Oral Slope Factor: 4.6 x10 -2 per mg/kg-day
Extrapolation Method: PBPK model-based route-to-route extrapolation of the inhalation unit risk estimate for kidney cancer with a factor of 5 applied to include non-Hodgkin's lymphoma (NHL) and liver cancer risks, combined risk
Tumor site(s): Hematologic, Hepatic, Urinary
Tumor type(s): Renal cell carcinoma, non-Hodgkin's lymphoma, and liver tumors (Charbotel et al., 2006 EPA, 2011 Raaschou-Nielsen et al., 2003)



Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (63 pp, 520 K)

Inhalation Unit Risk: 4.1 x10 -6 per µg/m3
Extrapolation Method: Low-dose linear extrapolation from the point of departure (LEC01) with a factor of 4 applied to include non-Hodgkin's lymphoma (NHL) and liver cancer risks, combined risk
Tumor site(s): Hematologic, Hepatic, Urinary
Tumor type(s): Renal cell carcinoma, non-Hodgkin's lymphoma, and liver tumors (Charbotel et al. 2006 EPA, 2011 Raaschou-Nielsen et al., 2003)


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