Draft Risk Evaluation Now Available for 1,2-Dichloroethane
In a draft risk evaluation released Nov. 14, EPA presents its preliminary determination that 1,2-dichloroethane, also known as ethylene dichloride, presents unreasonable risk of injury to human health and the environment under certain conditions of use. The 15 conditions of use identified as concerns include manufacturing; repackaging, recycling, and other processing operations; industrial uses in adhesives, sealants, lubricants, and greases, among others; commercial use as a laboratory chemical; and disposal. These conditions of use present dermal and inhalation risks to workers and inhalation risks to occupational non-users, according to EPA. The agency did not assess dermal exposures to occupational non-users since this group is not expected to directly handle 1,2-dichloroethane.
The draft risk evaluation presents an existing chemical occupational exposure value for inhalation exposures to 1,2-dichloroethane of 0.014 ppm, or 0.058 mg/m3, as an eight-hour, time-weighted average (TWA). Exposures to 1,2-dichloroethane below this concentration are not expected to increase risk of adverse effects, according to EPA. The agency may consider non-risk factors when determining an existing chemical exposure limit (ECEL) for 1,2-dichloroethane.
The current OSHA permissible exposure limit for 1,2-dichloroethane, adopted in 1979, is 50 ppm as an eight-hour TWA. OSHA acknowledges that many of its PELs are outdated and inadequate for protecting workers. Other eight-hour TWAs for 1,2-dichloroethane are California’s PEL and the NIOSH recommended exposure limit, which are set at 1 ppm, and the ACGIH Threshold Limit Value, which is 10 ppm.
EPA will accept comments on the draft risk evaluation following its publication in the Federal Register. The prepublication version of the draft risk evaluation (PDF) identifies areas that the agency seeks comment on, including its evaluation of 1,2-dichloroethane byproducts and the use of personal protective equipment and other controls. More information is available from the EPA website.
Between 2016 and 2019, the United States produced or imported between 30 and 40 billion pounds of 1,2-dichloroethane. Ninety percent of this production volume was used to make vinyl chloride, which is used in turn to create polyvinyl chloride or PVC.