EPA Releases Meeting Minutes and Final Report from Science Advisory Committee on Chemicals 1,1-Dichloroethane and 1,2-Dichloroethane Review
Released November 27, 2024
Today, the U.S. Environmental Protection Agency (EPA) released the meeting minutes and final report from the September 17-19, 2024, Science Advisory Committee on Chemicals (SACC) virtual public meeting regarding the 2024 draft Toxic Substances Control Act (TSCA) risk evaluation for 1,1-dichloroethane and the human health hazard assessment supporting the draft risk evaluation for 1,2-dichloroethane (also known as ethylene dichloride).
1,1-Dichloroethane is primarily used as an industrial and commercial solvent to make many different substances, including other chlorinated solvents (e.g., 1,1,1-trichloroethane) that have broad industrial applications. It is also used in relatively small amounts for laboratory research. 1,2-Dichloroethane is primarily used to manufacture vinyl chloride. Although 1,1-dichloroethane and 1,2-dichloroethane have different uses, the two chemicals are very similar in terms of their physical structure.
Information on EPA’s Draft Risk Evaluations for 1,1-Dichloroethane and 1,2-Dichloroethane
In the draft risk evaluation for 1,1-dichloroethane, EPA preliminarily found that seven of the eight uses of this chemical that EPA evaluated under TSCA significantly contribute to unreasonable risk.
Exposure to 1,1-dichloroethane may increase the risk of liver and other cancers, as well as harmful non-cancer renal, nasal, immune system, and reproductive effects to workers. EPA preliminarily found unreasonable risk from the manufacturing, processing, and disposal of 1,1-dichloroethane. EPA preliminarily found no unreasonable risk to the general population from breathing air where 1,1-dichloroethane was released from facilities or ingesting drinking water or surface water or soil from 1,1-dichloroethane disposed to land. EPA also found no unreasonable risk to potentially exposed and susceptible subpopulations, which included infants exposed to drinking water during formula bottle feeding, subsistence and tribal fishers, pregnant women and people of reproductive age, and individuals with compromised immune systems or neurological disorders. EPA did not assess consumer or bystander exposures because there are no commercial or consumer products or articles that contain 1,1-dichlorethane.
EPA’s draft risk evaluation preliminarily found that chronic exposure to 1,1-dichloroethane contributes to the unreasonable risk to aquatic species, including invertebrates and algae, from the manufacturing, processing, and disposal of 1,1-dichloroethane. EPA preliminarily determined that there is no unreasonable risk of injury to aquatic and terrestrial species from acute exposures to 1,1-dichloroethane.
EPA anticipates releasing the draft risk evaluation for 1,2-dichloroethane for public comment at a later date. EPA released the draft human health hazard assessment for 1,2-dichloroethane at the same time as the draft risk evaluation for 1,1-dichloroethane because data on the toxicity of 1,2-dichloroethane was used to fill gaps in the understanding of the toxicity of 1,1-dichloroethane for the draft risk evaluation. This is a well-established risk assessment practice for chemicals that have structural similarities. Feedback on the draft hazard assessment for 1,2-dichloroethane will also help inform the full 1,2-dichloroethane draft risk evaluation.
Information on the SACC Peer Review
EPA released its draft risk evaluation for 1,1-dichloroethane and draft human health hazard assessment for 1,2-dichloroethane for public comment and peer review in July 2024. The meeting minutes and final report are available in docket EPA-HQ-OPPT-2024-0114 on regulations.gov and through the SACC webpage for the 1,1-dichloroethane and 1,2-dichloroethane meeting. EPA is in the process of reviewing feedback from the meeting and will use this feedback, along with feedback received from the public, to inform the final risk evaluation for 1,1-dichloroethane and draft risk evaluation for 1,2-dichloroethane.
The SACC serves as a scientific peer review mechanism of EPA’s Office of Chemical Safety and Pollution Prevention. It provides independent scientific advice and recommendations to EPA on the scientific basis for risk assessments, methodologies and pollution prevention measures and approaches for chemicals regulated under TSCA.
For additional information about the SACC peer review, contact the Designated Federal Official, Alie Muneer at muneer.alie@epa.gov.