Chloroprene

Reference Dose for Oral Exposure (RfD) (PDF) (30 pp, 307 K) Last Updated: 09/30/2010

Information reviewed but value not estimated.

Reference Concentration for Inhalation Exposure (RfC) (PDF) (30 pp, 307 K) Last Updated: 09/30/2010

Weight of Evidence for Cancer (PDF) (30 pp, 307 K) Last Updated: 09/30/2010

• Under the Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005), there is evidence that chloroprene is "likely to be carcinogenic to humans"
• This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (30 pp, 307 K)

Information reviewed but value not estimated.

Inhalation Unit Risk: 3 x 10^-4 per µg/m³
Extrapolation Method: Multistage model with linear extrapolation from the point of departure (BMDL), summed risk.
Tumor site(s): Gastrointestinal, Respiratory, Other, Hepatic, Ocular, Reproductive, Dermal
Tumor type(s): alveolar/ bronchiolar adenoma or carcinoma hemangioma/ hemangiosarcoma (all organs) mammary gland adenocarcinoma, carcinoma, or adenoacanthoma forestomach squamous cell papilloma or carcinoma hepatocellular adenoma or carcinoma Harderian gland adenoma or carcinoma skin sarcoma and Zymbal's gland carcinoma (NTP, 1998)
Note: ADAF -- EPA has concluded that chloroprene is carcinogenic by a mutagenic mode of action. Application of age-dependent adjustment factors (ADAFs) to the inhalation unit risk is recommended in combination with appropriate exposure data when assessing risk associated with early-life exposure.