EPA: Inhalation Exposure to 1,1-Dichloroethane Presents Unreasonable Risk to Workers
Inhalation exposure to 1,1-dichloroethane presents an “unreasonable risk of injury to the health of workers,” according to EPA’s final risk evaluation of the chemical. 1,1-Dichloroethane is used mainly as an industrial and commercial solvent, to make other chlorinated solvents and other substances, and in small amounts for laboratory research, the agency says. Three conditions of use identified by EPA “significantly contribute” to 1,1-dichloroethane’s unreasonable risk to workers’ health. Two of those uses have to do with processing 1,1-dichloroethane as a reactant—both as an intermediate in basic organic chemical manufacturing and in other chemical product and preparation manufacturing, and the third use involves recycling.
“These risk determinations do not reflect the use of [personal protective equipment],” EPA’s news release explains. “[H]owever, as the risk evaluation shows, effective use of PPE in a manner that achieves a minimum APF 10 to 25 will reduce exposures and mitigate risk in the absence of other exposure controls (e.g., engineering controls).”
EPA finds that 1,1-dichloroethane’s use in manufacturing as an isolated intermediate, its distribution in commerce, and its commercial use in laboratory chemicals do not contribute significantly to the agency’s determination of unreasonable risk. Similarly, the agency says that repackaging and disposal of 1,1-dichloroethane do not add to the risk to workers’ health.
Given the inadequate data available on 1,1-dichloroethane, EPA used 1,2-dichloroethane, a chemical primarily used to produce vinyl chloride, as an analog for its human health hazard assessment.
“Based on the evidence in 1,2-dichloroethane animal studies, EPA believes that repeated inhalation exposure to 1,1-dichloroethane in workers over a lifetime can cause cancer,” the agency explains in a summary (PDF) of its risk evaluation.
EPA next plans to take risk management steps, including the proposal of a rule under section 6 of the Toxic Substances Control Act.
To learn more, read EPA’s news release or visit the agency webpage on 1,1-dichloroethane.
