EPA Preliminarily Determines That 1,2-Dichloroethane Poses Unreasonable Risk To Human Health And The Environment

On November 19, 2025, the U.S. Environmental Protection Agency (EPA) announced the availability of and requested comment on a draft risk evaluation under the Toxic Substances Control Act (TSCA) for 1,2-dichloroethane (Chemical Abstracts Service Registry Number^® (CAS RN^®) 107-06-2, also known as ethylene dichloride or EDC). 90 Fed. Reg. 52054. EPA notes that the purpose of risk evaluations under TSCA is to determine whether a chemical substance presents an unreasonable risk of injury to health or the environment under the conditions of use (COU), including unreasonable risk to potentially exposed or susceptible subpopulations identified as relevant to the risk evaluation by EPA, and without consideration of costs or non-risk factors. EPA states that it used "the best available science to prepare this draft risk evaluation and to preliminarily determine, based on the weight of scientific evidence, that EDC poses unreasonable risk to human health and the environment driven primarily by certain COUs analyzed in the draft risk evaluation." Comments on the draft risk evaluation are due January 20, 2026. The draft risk evaluation and supporting documents are available on EPA's website.

Draft Risk Evaluation for EDC

EPA states on its website that it is preliminarily determining that EDC presents unreasonable risk of injury to human health driven by inhalation and dermal risks to workers and inhalation risks to occupational non-users (ONU) from 15 COUs. EPA is also preliminarily determining that EDC presents an unreasonable risk to the environment driven by chronic exposure to aquatic invertebrates via surface water and sediment exposures from two COUs. EPA notes that it did not preliminarily identify a risk of injury to human health or the environment from five other COUs. For COUs with unreasonable risk to workers, the preliminary risk determinations do not reflect the use of personal protective equipment (PPE), although as shown by the draft risk evaluation, the use of PPE may reduce exposure and mitigate risk.

EPA states that it is preliminarily determining that EDC exposure to consumers or the general population, associated with any COU, does not significantly contribute to unreasonable risk of injury to human health.

Background on EDC

EPA states that EDC "is a volatile, colorless, oily liquid with a chloroform-like odor, and is miscible in most organic solvents." According to EPA, the primary use of EDC is in plastic material manufacturing to manufacture vinyl chloride. EPA notes that information from the 2016 Chemical Data Reporting (CDR) for EDC indicates the reported volume is between 30 and 40 billion pounds per year.

Uses of EDC

In the final scope, EPA identified COUs associated with the manufacturing (including importing); processing; distribution in commerce; industrial, commercial and consumer uses; and disposal of EDC, for example:

• In the manufacturing of petrochemical, plastic material and resin, and other basic organic chemicals;

• In the manufacturing of petroleum and coal products and petroleum production;

• In adhesives and sealants and heat transferring agents;

• In lubricants and greases;

• In solvents (for cleaning and degreasing);

• As an industrial oxidizing inhibitor; and

• In plastic and rubber products.

According to EPA, these COUs are ways that a person or the environment could be potentially exposed. EPA notes that when it conducts a TSCA risk evaluation, it also considers the hazards (i.e., health effects or environmental impacts) that could occur from coming in contact with a chemical.

Request for Comment

EPA states in the Federal Register notice that it seeks feedback on the assessment of risk presented in the draft risk evaluation and "encourages all potentially interested parties, including individuals, governmental and non-governmental organizations, non-profit organizations, academic institutions, research institutions, and private sector entities to comment on the draft risk evaluation." To the extent possible, the Agency asks commenters to cite any public data related to or that support comments provided, and to the extent permissible, describe any supporting data that is not publicly available.

EPA welcomes specific input on each section of the draft risk evaluation, particularly input on the following:

• The approach taken to evaluate the byproducts in the Draft Byproducts Assessment for 1,2-Dichloroethane;

• The COU names and descriptions for "Industrial use — other use — process solvent," particularly whether there is overlap between this use as a process solvent in chemical reactions (including a proprietary use in pesticide, fertilizer, and other agricultural chemical manufacturing) and other processing or industrial and commercial COUs that may duplicate this newly added COU (e.g., Processing — incorporated into a formulation, mixture, or reaction product);

• Whether the delineation of occupational exposure scenarios (OES) associated with the Disposal COU are clear and accurate;

• Whether and how exposure controls and PPE are used during the manufacture, processing, and use of EDC for each of the COUs. EPA states that although it has test order data, "additional information on when and where exposure controls and PPE are used would be informative";

• All aspects of the approach for assessing ambient air inhalation exposure for the general population, including exposure input assumptions, uncertainties, as well as the calculation and interpretation of additional cancer cases based on the population exposed;

• Information on environmental releases for OESs for which releases were modeled (Repackaging, Application of adhesives and sealants, Industrial and commercial non-aerosol cleaning/degreasing, Application of lubricants and greases, Industrial and commercial aerosol products, and Laboratory use);

• Information on OESs for which EPA has slight confidence on exposures to workers and ONUs (Repackaging, Industrial and commercial aerosol products, and Waste handling, treatment, and disposal [landfills]), including on the degree to which EDC is used in Industrial and commercial aerosol products. Information to help clarify the approach EPA used to analyze U.S. Occupational Safety and Health Administration (OSHA) chemical exposure health data (CEHD), "specifically the step of removing data in which all measurements taken at the site were recorded as '0' or below the limit of detection and there was no evidence such as a bulk sample that shows the presence of the chemical at the site as EPA assumed that the chemical of interest may not have been at the site at the time of sampling"; and

• Information (e.g., safety data sheet (SDS) documents) to inform the level of EDC in adhesives. The concentration evaluated for the dermal exposure for the Industrial application of adhesives and sealants OES is 91.8 percent based on an SDS for an adhesive containing EDC.

Commentary

Bergeson & Campbell, P.C. (B&C^®) applauds EPA and the staff in the Office of Pollution Prevention and Toxics (OPPT) for continuing its efforts to carry out its TSCA risk evaluation responsibilities, despite an unprecedented number of challenges that likely made the development and release of this draft risk evaluation difficult. EPA just emerged from the longest federal government shutdown in U.S. history. While the extent of furloughs in OPPT was unclear, one can assume that the gears of government slowed during those 43 days, making it more challenging for EPA to complete this work. In addition, work on the EDC risk evaluation (initiated in 2019) has spanned three administrations and three different versions of the procedural framework rule for conducting risk evaluations, each espousing different policies and approaches for how EPA will meet its requirements under TSCA. On top of that, the release of this draft comes amid a backdrop of numerous legal challenges regarding issues central to TSCA risk evaluations, including the extent of EPA's discretion to determine "conditions of use" in the scope of the assessment, the appropriate approach for considering occupational exposures and risks, the scientific approaches and assumptions used to support "unreasonable risk" conclusions, and the framing of EPA's risk determination in the context of the chemical as a whole versus individual COUs. Navigating these shifting landscapes and uncertainties made it more difficult to get to this point.

EDC is one of 20 substances designated as high priority for risk evaluation almost six years ago in December 2019, and EPA has long since missed its three-year statutory deadline to complete a final risk evaluation. This extended timeline included two rounds of TSCA Section 4 test orders from EPA in 2021 and 2022 mandating facility-specific occupational exposure testing and environmental hazard testing, respectively. EPA may consider whether the mandating of test orders is better initiated ahead of prioritization of a substance for risk evaluation as the time required to complete test orders unduly extends the timeline for completing risk evaluations. EPA's extended timelines for risk evaluation prompted litigation in 2023 and a subsequent consent decree in 2024 that set a new, judicially-enforceable schedule for EPA to complete its work, as reported in our December 5, 2024, blog item.

EPA has kept pace with the schedule, completing — as required in the consent decree — various draft and final risk evaluations by December 31, 2024, and another draft risk evaluation by March 31, 2025. The next consent decree deadline requires EPA to finish seven more final risk evaluations no later than December 31, 2025. EPA's Annual Plan for chemical risk evaluations under TSCA forecasts the seven chemicals EPA is targeting to satisfy this deadline, including EDC, as well as 1,3-butadiene, butyl benzyl phthalate (BBP), dibutyl phthalate (DBP), dicyclohexyl phthalate (DCHP), di-(2-ethylhexyl) phthalate (DEHP), and diisobutyl phthalate (DIBP). Notably, while EPA has now issued draft risk evaluations for all seven chemicals, EPA has yet to issue final risk evaluations as required by the consent decree. While there are still a few weeks left in the year, it is hard to imagine a scenario where EPA is able to comply timely. This is particularly true for EDC, which was just released in draft form and has an open public comment period that extends beyond the consent decree deadline into 2026. Absent further modifications to the consent decree, a failure to issue the final risk evaluations by the end of the calendar year could result in judicial enforcement and oversight, including potentially contempt of court proceedings.

The draft risk evaluation also signals some changes in EPA's approach. EPA had stated in its Final Scope that:

EPA does mention all the chlorinated solvents specified in the Final Scope in this draft risk evaluation for EDC, but EPA does not assess quantitatively risk from 1,1,2-trichloropropane (1,1,2-TCP) or trans-1,2-dichloroethylene (TDCE). EPA calculates risk for the other chlorinated solvents, each of which has been subjected to peer review. EPA may be more confident calculating risk values using peer-reviewed points of departure (POD). EPA has yet to publish draft hazard assessments or draft risk evaluations or for 1,1,2-TCP or TDCE, so neither has been subjected to peer review.

Perhaps most notable is that in this assessment, buried in the Draft Byproducts Assessment for 1,2-Dichloroethane, EPA selected a POD for TCE that is different from the one EPA used as a basis for its Existing Chemical Exposure Limit (ECEL) in the TCE risk management rule. In this assessment, EPA used immunotoxicity effects (Keil et al., 2009) as the basis for the POD for TCE in EDC. In the risk management rule, EPA selected fetal congenital heart defects (Johnson et al., 2003) as the basis for the POD for the TCE ECEL. This may signal how EPA intends to approach updating the TCE risk management rule, which readers may recall has been challenged in court, but the case has been held in abeyance.

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