IRIS

1,2-Dibromoethane

CASRN 106-93-4

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (34 pp, 241 K) last updated: 07/29/2004

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Endocrine, Reproductive, Hepatic 9 x 10-3 Testicular atrophy, liver peliosis, and adrenal cortical degeneration LOAEL : 27
mg/kg-day
3000 Low/Medium

 


Reference Concentration for Inhalation Exposure (RfC) (PDF) (34 pp, 241 K) last updated: 07/29/2004

System RfC (mg/m3) Basis PoD Composite UF Confidence
Respiratory 9 x 10-3 Nasal inflammation BMCL10 (HEC): 2.8
mg/m3
300 Medium

 

Cancer Assessment

Weight of Evidence for Cancer (PDF) (34 pp, 241 K) last updated: 07/29/2004

WOE Characterization Framework for WOE Characterization
Likely to be carcinogenic to humans Revised Draft Guidelines for Carcinogen Risk Assessment (US EPA, 1999)
Basis:
  • Under the Draft Revised Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1999), 2-dibromoethane is considered "likely to be carcinogenic to humans" based on strong evidence of carcinogenicity in animals and inconclusive evidence of carcinogenicity in an exposed human population.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (34 pp, 241 K)

Oral Slope Factor: 2 per mg/kg-day (95% upper bound)
Drinking Water Unit Risk: 6 x10 -5 per µg/L (95% upper bound)
Extrapolation Method: Multistage model with Poly-3 adjusted incidence data linear extrapolation from lower 95% confidence limit on dose associated with extra risk (adjusted for background) at point of departure at lower end of data range.
Tumor site(s): Other, Gastrointestinal, Endocrine
Tumor type(s): Forestomach tumors, hemangiosarcomas, thyroid follicular cell adenomas or carcinomas (NCI, 1978)


Oral Slope Factor: 1 mg/kg-day (central tendency estimate)
Extrapolation Method: Multistage model with Poly-3 adjusted incidence data central tendency estimate
Tumor site(s): Other, Gastrointestinal, Endocrine
Tumor type(s): Forestomach tumors, hemangiosarcomas, thyroid follicular cell adenomas or carcinomas (NCI, 1978)



Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (34 pp, 241 K)

Inhalation Unit Risk: 6 x10 -4 per µg/m3 (95% upper bound)
Extrapolation Method: Multistage-Weibull model linear extrapolation from lower 95% confidence limit on dose associated with extra risk (adjusted for background) at point of departure at lower end of data range.
Tumor site(s): Reproductive, Other, Respiratory
Tumor type(s): Nasal cavity (includes adenoma, adenocarcinoma, papillary adenoma, squamous cell carcinoma, and or/papilloma), hemangiosarcomas, mesotheliomas (NTP, 1982)


Inhalation Unit Risk: 3 x10 -4 per µg/m3 (central tendency estimate)
Extrapolation Method: Multistage model with Poly-3 adjusted incidence data central tendency estimate
Tumor site(s): Reproductive, Other, Respiratory
Tumor type(s): Nasal cavity (includes adenoma, adenocarcinoma, papillary adenoma, squamous cell carcinoma, and or/papilloma), hemangiosarcomas, mesotheliomas (NTP, 1982)


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