Risk Evaluation for 1,2-Dichloroethane

EPA determined that 1,2-DCA presents an unreasonable risk of injury to human health driven by inhalation and dermal risks to workers under 15 of 20 total conditions of use (COUs); 12 of these COUs also present unreasonable risk to occupational non-users (ONUs). The risk determination reflects baseline workplace exposures; however, specified respirators and other workplace controls can reduce worker exposures such that the risk would no longer be unreasonable. 

EPA did not identify unreasonable risk to consumers, the general population, or the environment under any COU. 

As required by TSCA, EPA will now develop a rule to protect workers from the risks we identified. The agency will carefully consider health effects, exposure levels, how the chemical benefits society, and economic impacts. Input from workers, companies, and the public will be crucial to make sure our final rule protects health while being protective of vulnerable populations like women who are pregnant or of childbearing age and practical for businesses. 

This next step, when finalized, will give companies clear rules to follow and provide workers with the protections they need to stay safe on the job. 

EPA determined that 1,2-DCA presents an unreasonable risk to human health driven by worker inhalation and dermal exposures under 15 of 20 total COUs. Twelve of these 15 COUs also present unreasonable risk to occupational nonusers—workers who are in the workplace but do not directly handle the chemical. EPA did not identify unreasonable risk to consumers, the general population, or the environment under any COU evaluated. 

The health evidence that informed EPA’s conclusions includes laboratory studies indicating kidney toxicity following ingestion and respiratory (nasal) and male reproductive system toxicity following inhalation. Based on these animal data, EPA concluded that repeated workplace inhalation or dermal exposure over a working lifetime can cause cancer, including for occupational nonusers. 

The risk determination reflects baseline workplace exposures and does not assume the routine use of personal protective equipment or other engineered controls. However, the evaluation indicates that specified respirators and other workplace controls can reduce exposures such that the risk would no longer be unreasonable. Accordingly, EPA’s forthcoming risk management will focus on the specific COUs that drive these workplace risks. 

EPA also identified five COUs that do not significantly contribute to unreasonable risk to human health: distribution in commerce; industrial use as functional fluids in closed systems as a heat transferring agent; commercial use in plastic and rubber products; commercial use in fuels and related products; and consumer use in plastic and rubber products. 

In assessing potentially exposed or susceptible subpopulations, EPA evaluated workers; consumers; members of the general population who may be exposed through environmental releases; people who may be at greater risk due to age, genetics, or preexisting health conditions; and communities with high fish consumption, including some Tribal and subsistence communities. High fish consumption was considered because, if a chemical reaches surface waters, people who eat a lot of locally caught fish may be exposed through their diet. EPA did not identify unreasonable risk through this pathway for 1,2DCA under any COU. 

For the environment, EPA did not identify unreasonable risk under any COU. The evaluation considered aquatic vertebrates, aquatic invertebrates, algae, and land animals at environmentally relevant concentrations. EPA also evaluated several byproducts formed during the manufacture of 1,2-DCA; two byproducts—trans1,2dichloroethylene and 1,1,2trichloroethane—will be evaluated in separate TSCA risk evaluations. 

Q: Who is most affected—and who wasn’t found to face unreasonable risk?  

A: Most affected: Workers (and nearby ONUs) in certain manufacturing, processing, industrial use, and disposal settings. Not found to significantly contribute to unreasonable risk in this evaluation: Consumers and the general public—including high fish consuming Tribal and subsistence communities—and the environment, under the TSCA COUs evaluated. 

Q: Why did EPA focus on direct workplace exposure?  

A: TSCA requires us to evaluate the manufacturing, processing, distribution, use, and disposal of chemicals in a risk evaluation. We evaluated all these uses.  We found that the highest risks occur in the workplace. Our gold standard science approach requires us to look at all sources of exposure covered by TSCA.  

Q: What about communities near facilities using 1,2-DCA?  

A: EPA evaluated potential exposures to the general population from releases to air, water/sediment, and land under each condition of use, including people who live near facilities. Based on best available science at environmentally relevant concentrations, EPA did not identify unreasonable risk to the general population or the environment under any condition of use. EPA also assessed dietary exposure for communities with high fish consumption and did not identify unreasonable risk. Upcoming risk management will focus on workplace exposures, and EPA will continue coordinating with other programs and welcomes community data. 

Q: Why did some of your findings change from the draft to the final evaluation?  

A: The final evaluation incorporates public comments and external peer review by the Science Advisory Committee on Chemicals (SACC). EPA updated and clarified methods, considered new or refined workplace and use information, and replaced overly conservative assumptions where better real-world data were available. These improvements led to refined exposure estimates and risk conclusions—most notably, the final determination that EPA did not identify unreasonable environmental risk under any condition of use. The final reflects the weight of the scientific evidence and best available science. 

Q: Will workers be protected even though you found risks? 

A: Yes. Part of EPA’s statutory obligations include the requirement to develop rules to protect workers from the unreasonable risks we identified. These rules will ensure that companies’ workers are kept safe.

EPA’s Commitment to Gold Standard Science