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

The United States Environmental Protection Agency has officially advanced its regulatory review of ethylene dibromide, releasing a comprehensive draft risk evaluation under the Toxic Substances Control Act that pinpoints significant occupational hazards. Published in the Federal Register on August 19, 2026, the preliminary assessment determines that the chemical poses unreasonable risks of injury to workers and occupational non-users across multiple conditions of use. As the agency opens a mandatory public comment period, industry stakeholders, labor representatives, and environmental compliance professionals are closely analyzing the regulatory trajectory of a chemical deeply entrenched in specific industrial and aviation sectors.

Core Findings of the Draft Risk Evaluation

The EPA’s preliminary review indicates that ethylene dibromide (EDB)—primarily utilized as a lead scavenger in leaded aviation gasoline, commonly known as avgas, alongside select industrial and commercial applications—contributes significantly to unreasonable risks via inhalation and dermal exposure. Specifically, the draft evaluation isolates ten distinct conditions of use where workers and occupational non-users face elevated health hazards. These exposure scenarios span the chemical’s lifecycle, encompassing manufacturing, import, processing, distribution, industrial and commercial applications, aircraft refueling operations, and disposal procedures.

Despite the stringent findings concerning occupational health, the draft evaluation draws a distinct line regarding other populations. Based on reasonably available scientific information, the EPA has concluded that the substance does not present an unreasonable risk to consumers, the general public, or the broader environment when evaluated independently.

Furthermore, the agency has taken care to delineate the scope of its assessment regarding aviation fuel. Because EDB is predominantly deployed alongside lead in avgas, the EPA explicitly clarified that the current document evaluates the chemical hazards of ethylene dibromide itself, rather than the associated lead content. Regulation of lead emissions remains governed under separate federal authorities, including the EPA’s 2023 endangerment finding for aircraft lead emissions and collaborative efforts with the Federal Aviation Administration under the Eliminate Aviation Gasoline Lead Emissions initiative.

Regulatory Chronology and the TSCA "Next 20" Mandate

The release of the draft risk evaluation for ethylene dibromide represents another critical milestone in a tightly constrained statutory timeline established by federal litigation and subsequent consent decrees. EDB belongs to the cohort of chemicals designated as high-priority substances in 2019 under amended provisions of the Toxic Substances Control Act. These substances, frequently referred to in regulatory circles as the "next 20" chemicals, became the subject of extensive legal challenges that ultimately compelled the EPA to adhere to strict statutory deadlines for completing comprehensive risk evaluations.

The progression of this regulatory queue has moved swiftly through the first half of 2026. Following the publication of a draft risk evaluation for 1,2-dichloropropane earlier in August 2026, ethylene dibromide joins a rapidly dwindling list of preliminary assessments. With its release, only a single chemical—phosphoric acid, triphenyl ester—remains in the draft queue awaiting initial publication.

However, the administrative path forward leaves little room for delay. Under the prevailing court-ordered consent decree, the EPA must navigate a rigorous sequence of regulatory steps before a final risk evaluation for EDB can be published. This mandatory workflow includes a public comment period closing on October 19, 2026, subsequent peer review by the Scientific Advisory Committee on Chemicals, formal incorporation of public and expert recommendations, and the ultimate issuance of a final risk evaluation by February 2027. This compressed timeline runs parallel to similar administrative pressures facing nine other high-priority chemicals currently moving through the same statutory queue.

Statutory Constraints and Analytical Framework

Under the statutory framework of TSCA Section 6, the EPA is legally mandated to execute risk evaluations based strictly on the weight of scientific evidence. The primary objective is to determine whether a chemical substance presents an unreasonable risk of injury to human health or the environment under its conditions of use, taking into account potentially exposed or susceptible subpopulations such as workers and children.

Crucially, the statute explicitly prohibits the agency from considering non-risk factors, such as economic costs, financial burdens, or potential commercial benefits, during the risk evaluation phase. Only when the agency transitions from evaluation to risk management—provided an unreasonable risk is finalized—does the regulatory framework permit the balancing of economic and practical considerations under Section 6(a).

This procedural separation has historically intensified debate surrounding how occupational exposures are calculated. A central point of discussion among legal and industry experts involves the assumptions made regarding workplace personal protective equipment. The EPA’s broader regulatory agenda has previously explored shifts in how worker protections are factored into preliminary assessments, raising questions about whether baseline evaluations should account for the routine and reliable utilization of protective gear in industrial settings.

Broader Implications for Industry and Occupational Safety

The identification of unreasonable risks to workers in the EDB draft evaluation casts light on broader coordination challenges between federal agencies, specifically regarding the overlapping jurisdictions of the EPA under TSCA and the Occupational Safety and Health Administration. For decades, industry stakeholders have advocated for streamlined synchronization between the two regulatory bodies to avoid conflicting compliance mandates, dual reporting structures, and administrative redundancies for businesses operating in sectors reliant on high-priority chemicals.

Under TSCA Section 9, the EPA maintains the statutory authority to refer identified occupational risks to other federal agencies, such as OSHA, for regulatory action under their respective legislative authorities. How the current administration elects to utilize this provision for EDB and other occupational risk chemicals remains a focal point of industry observation. Past regulatory actions under TSCA Section 6 have occasionally generated complex compliance landscapes, making the upcoming public comment and risk management phases crucial periods for stakeholder engagement.

Public Participation and Next Steps

With the publication of the notice in the Federal Register, the EPA is actively soliciting specific technical data, peer-reviewed literature, and empirical feedback on all sections of the draft risk evaluation. Stakecasters, industry representatives, labor organizations, and academic researchers have until October 19, 2026, to submit formal comments to the public docket.

Following the conclusion of the comment window, the EPA will compile the submissions for review by the Scientific Advisory Committee on Chemicals. Insights from the SACC peer review, alongside public comments, will form the foundation for the final risk evaluation scheduled for release in early 2027. Should the final evaluation reaffirm the existence of unreasonable occupational risks, the agency will be required to initiate formal rulemaking under TSCA Section 6(a) to propose targeted risk management controls designed to mitigate worker and occupational non-user exposures.