EPA Releases Scientific Analysis of Potential Exposure to trans-1,2-Dichloroethylene and 1,2-Dichloropropane, Advance Review under TSCA
Released on July 31, 2026
U.S. Environmental Protection Agency (EPA) is advancing its review of trans‑1,2‑dichloroethylene and 1,2‑dichloropropane under the Toxic Substances Control Act (TSCA) by releasing draft technical support documents that explain how the agency estimates exposure to these common solvents. trans‑1,2‑Dichloroethylene is a colorless liquid with a sharp, harsh odor and is used in cleaning and degreasing and in industrial and commercial products. 1,2‑Dichloropropane is a chlorinated solvent that evaporates easily into the air and is used in industrial processing and as an intermediate. Evaluating potential risks from these solvents is important because they are widely used in industry and may be present in consumer products and can travel through air and water, leading to possible exposures at work, at home, and in nearby communities. Under TSCA, EPA is required to consider potentially exposed or susceptible subpopulations, which can include workers, pregnant women, infants and children, and people who live near where these chemicals are used. A clear, science-based understanding of exposure helps EPA identify who may be most affected and where to focus its analysis.
These technical documents show how EPA uses the best available science to understand the potential releases of these chemicals into the environment and how people might come into contact with them. The assessments describe each chemical’s properties; how they move and break down in air, water, and soil; where releases may occur; and what that means for potential exposure to workers, consumers, the general public, and wildlife. They combine measured data and established models to estimate exposures through multiple pathways (for example, workplace air, indoor air, drinking water, and surface water) and explain the assumptions and uncertainties behind those estimates. These documents are drafts and do not make final risk conclusions. These documents support the forthcoming draft risk evaluations for each chemical. EPA is releasing them as soon as they are available to provide the public additional time to review the scientific analyses and to make them available in advance of the August Science Advisory Committee on Chemicals meeting, where they will provide context for the peer review. The full public comment period will occur with the draft risk evaluations when they are released. EPA will release the full draft risk evaluations for public comment and then consider all input before finalizing our assessments.
The documents released today show the following:
- trans-1,2-Dichloroethylene: EPA's draft exposure assessment for trans-1,2-dichloroethylene characterizes releases to air, water, and land and evaluates potential occupational, consumer, general population, and environmental exposures associated with the manufacture, processing, laboratory activities, disposal, and reasonably foreseen industrial, commercial, and consumer uses of the chemical.
- 1,2-Dichloropropane: EPA's draft exposure assessment for 1,2-dichloropropane characterizes releases to air, water, and land and evaluates potential occupational, consumer, general population, and environmental exposures associated with manufacturing, processing, laboratory activities, disposal, and reasonably foreseen industrial, commercial, and consumer uses of the chemical.
The exposure technical support documents are intended to provide stakeholders with insight into the scientific methods and data that support EPA's draft risk evaluations. These exposure technical support documents will be available for public comment in their respective TSCA public review dockets at a later date once the draft risk evaluations have been released (EPA-HQ-OPPT-2018-0465 for trans-1,2-dichloroethylene; EPA-HQ-OPPT-2018-0428 for 1,2-dichloropropane). At that time, EPA will welcome public review and comment before finalizing the risk assessments for these chemicals. Scientific analyses of human health and environmental effects of these chemicals are undergoing independent peer review by the Science Advisory Committee on Chemicals during a meeting from Aug. 3-7, 2026.
All current protections for these chemicals remain in place while EPA completes this review; releasing draft scientific analyses does not alter any existing safeguards. These draft documents do not represent EPA's final determination regarding the risks posed by these chemicals. Findings and conclusions may change based on feedback received during the public comment period and based on external peer review of the underlying science.
The documents released today are available on EPA’s website and will be added to the following public dockets: EPA-HQ-OPPT-2018-0465 for trans-1,2-Dichloroethylene and EPA-HQ-OPPT-2018-0428 for 1,2-Dichloropropane.