EPA Draft TSCA Risk Evaluation of Ethylene Dibromide Identifies Significant Contributions to Unreasonable Risk to Workers and Occupational Non-Users

On August 19, 2026, the U.S. Environmental Protection Agency (EPA) announced the availability of and requested public comment on the draft risk evaluation under the Toxic Substances Control Act (TSCA) for ethylene dibromide. 91 Fed. Reg. 53618. EPA states 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. Comment on the draft risk evaluation are due October 19, 2026.

Draft Risk Evaluation for Ethylene Dibromide

According to EPA’s August 18, 2026, press release, ethylene dibromide “is primarily used in fuels and related products as a lead scavenger in leaded aviation gasoline [(avgas)] and in certain industrial and commercial applications.” EPA notes that it evaluated potential risks across ethylene dibromide’s lifecycle since workers and occupational non-users (ONU) may be exposed during manufacturing (import), processing, distribution, industrial use, commercial use, aircraft refueling activities, and disposal while consumers may be exposed during aircraft refueling activities. EPA states that the draft risk evaluation identifies significant contributions to unreasonable risk to workers and ONUs from inhalation and/or dermal exposure under ten COUs. Based on the reasonably available information, the draft risk evaluation “does not identify unreasonable risk to consumers, the general population, or the environment from ethylene dibromide itself.”

EPA notes that because ethylene dibromide is used primarily as a lead scavenger in leaded avgas, it “wants to be clear about what this draft does and does not cover. This draft evaluation assesses ethylene dibromide, not the lead in avgas, which EPA addresses through separate authorities.” EPA states that its 2023 endangerment finding for aircraft lead emissions remains in effect, and EPA continues to support the Federal Aviation Administration (FAA)-led transition and the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative to eliminate leaded aviation fuel.

Request for Comment

EPA states in the Federal Register notice that it “welcomes specific input on each section of the draft risk evaluation, and is particularly interested in”:

• Information to inform whether the data used (e.g., worker activities, process descriptions, exposure monitoring data) for the Incorporation into Formulation, Mixture or Reaction Product occupational exposure scenario (OES) are representative and reliable for current exposures scenarios;

• Facility-specific information on days of operation and/or release to characterize environmental releases more accurately;

• Facility-specific information on days of operation and hours of operation per day for batch processes to characterize occupational exposure accurately;

• Any exposure monitoring data gathered from facilities relevant to current COUs for ethylene dibromide;

• Information to inform whether the data used for the Laboratory Use OES is representative and reliable for ongoing practices, including use-related information (e.g., volume of ethylene dibromide), workers’ activity-specific details (e.g., typical working hours/day and days/year, frequency and duration of ethylene dibromide use on a typical workday, personal protective equipment (PPE) used), and site-specific information (e.g., location of the site, engineering controls, size of laboratory site). EPA seeks further information on exposures in federal and non-federal laboratories;

• Information from ethylene dibromide processing facilities on the current presence of laboratory sites within the same facilities;

• Information on the introduction of any exposure reduction-related technologies or engineering controls since the 1980s;

• Information on PPE enforced by employers (e.g., assigned protection factor (APF) of respirators, materials of gloves, duration of respirator or gloves used) and used by workers in various activities under each OES;

• Average working hours per day and number of working days for a worker that refuels single engine small aircraft that utilize 100LL avgas containing ethylene dibromide as a fuel agent or additive;

• Number of aircrafts a worker (avgas refueler) refuels on a typical eight-hour workday;

• Avgas use patterns (e.g., frequency of refueling an aircraft per day, number of days flying an aircraft per year, average number of years that a consumer may fly and refuel their aircraft) for consumers (i.e., pilots of small non-commercial airplanes);

• Racing fuel availability and use patterns (e.g., number or types of vehicles using racing fuel containing ethylene dibromide, volume of use, frequency of refueling);

• Average duration of refueling an aircraft (i.e., the duration of actively transferring avgas from nozzle into an aircraft fuel tank) and average volume of avgas refueled into an aircraft;

• Worker activities, industrial and commercial practices for the disposal of ethylene dibromide, and any exposure monitoring data gathered at landfills or wastewater treatment plants;

• EPA’s draft Occupational Exposure Value (OEV) and Short-Term Exposure Value (STEV);

• Number of operating days per year and shift lengths at bulk terminals under the Fuels and Related Products OES;

• Information regarding engineering controls, administrative controls, and/or PPE use by workers engaged in refueling activities that reduce inhalation and dermal exposure to ethylene dibromide; and

• The representativeness of high-end exposure estimates for intermediate inhalation and dermal occupational exposures (e.g., current practices involving the processing of ethylene dibromide at neat concentrations).

Next Steps

EPA states that after considering public comments on the draft risk evaluation and input from the Scientific Advisory Committee on Chemicals (SACC) peer review, it will issue a final risk evaluation for ethylene dibromide. Under TSCA Section 6, EPA must use the final risk evaluation as a basis to determine, based on the weight of scientific evidence, whether the chemical presents an unreasonable risk to human health or the environment under the chemical’s COUs. EPA notes that this includes risks to subpopulations who may be at greater risks than the general population, such as children and workers. TSCA prohibits EPA from considering non-risk factors (e.g., costs/benefits) during risk evaluation.

After considering public and SACC comments, EPA will prepare a final evaluation. If EPA continues to find unreasonable risk, it will propose risk management actions under TSCA Section 6(a) to address those exposures “on a clear and accountable timeline.”

Commentary

After years of circling the proverbial EPA airport, ethylene dibromide has finally been cleared for (temporary) landing. Ethylene dibromide is one of the last draft risk evaluations to be published in the “next 20” chemicals designated as high-priority substances in 2019 that were the subject of litigation, and a resultant consent decree that imposed various milestones and deadlines for completing risk evaluations under TSCA. With the publication of a draft risk evaluation for 1,2-dichloropropane earlier this month, only one chemical remains in the draft queue — phosphoric acid, triphenyl ester (TPP) — still patiently awaiting its time on the runway. Unfortunately for EPA, ethylene dibromide — like other TSCA chemicals we have discussed in our previous memoranda — will need take off again pretty quickly: undergo a period of public comment, receive formal SACC feedback, consider and incorporate those comments and recommendations, refuel, wheels up, and in the air — all before a February 2027 court-ordered deadline for publishing the ethylene dibromide risk evaluation in final. Ethylene dibromide is just one of ten remaining chemicals under the same time restraints in this queue, setting up what is sure to be quite the high-flying feat of scientific production and air traffic control for EPA staff in the six months ahead.

Seemingly also in a holding pattern are a number of key policies related to assessing and managing risks to workers, particularly relevant to ethylene dibromide given EPA’s identification of occupational risks. First, the public is still awaiting a final rule updating EPA’s framework for conducting risk evaluations under TSCA. In the 2025 proposed rule, EPA proposed a shift away from EPA’s prior approach of assessing chemical risks to workers without assuming that PPE was regularly and reliably used, or that it adequately reduced exposures. It begs the question of how the ethylene dibromide draft risk evaluation and its conclusions, for example, might change if the proposed framework rule approach were adopted in final and applied. Although the Unified Regulatory Agenda suggested that EPA would publish a final risk evaluation framework rule in July 2026, we expect major EPA rules and announcements might be grounded until post-midterm elections.

Second, we are still eagerly anticipating an opportunity to see how EPA in this Administration approaches risk management for identified risks to workers. Largely untested is TSCA Section 9 — a quiet but powerful provision that allows EPA to refer risks to other federal agencies for action under their respective statutes. For years, industry has criticized EPA for not coordinating closely enough with the U.S. Occupational Safety and Health Administration (OSHA) on both the assessment and management of occupational risks. EPA’s efforts to impose worker protections under TSCA Section 6 have resulted in overlapping and potentially conflicting requirements between EPA and OSHA, creating confusion for businesses that already struggle to keep pace with an ever-changing and increasingly complex regulatory environment. The year ahead promises to be full of opportunity for advocacy to reduce some of the unnecessary turbulence in the risk management space.

In any event, The Acta Group has secured its tickets on the TSCA risk evaluation redeye, and we will be watching closely to see how EPA responds to the comments and suggestions for greater scientific, legal, and policy rigor we often make on behalf of our clients. Although ever the blue-sky optimists, if you, too, are along for this ride, we suggest fastening your seatbelts and keeping your chair in the upright position.