US EPA

EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of chloroprene that will appear on the Integrated Risk Information System (IRIS) database.

The draft Toxicological Review of chloroprene provides scientific support and rationale for the hazard and dose-response assessment pertaining to chronic exposure to chloroprene. Chloroprene (C4H5Cl) is a volatile, flammable liquid used primarily in the manufacture of polychloroprene or neoprene rubber. The latter is used to make diverse products, such as tires, wire coatings, and tubing. Human health risk concerns for chloroprene are primarily related to exposures via effluent and emissions from facilities that use chloroprene to produce polychloroprene elastomers or transport the product, although these exposure concerns have not been well characterized.

This assessment contains the derivation of a chronic inhalation reference concentration (RfC) and chronic cancer inhalation unit risk.

Chloroprene (CASRN 126-99-8) or 2-chloro-1,3-butadiene is a volatile liquid monomer used exclusively in the manufacture of polychloroprene (neoprene) elastomer.

Following External Peer Review, the final assessment is scheduled to be posted to the IRIS database.

U.S. EPA. IRIS Toxicological Review of Chloroprene (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-09/010AF, 2009.

Comments on the assessment may be submitted and reviewed using the e-Government Regulations.gov Web site. From the site, select “Environmental Protection Agency” and the key word “EPA- HQ-ORD-2009-0217” (for the docket ID).