Fifth Circuit Vacates EPA’s Methylene Chloride Risk Management Rule

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In a groundbreaking decision with significant implications for the regulation of existing chemicals under the Toxic Substances Control Act (TSCA), the Fifth Circuit vacated EPA’s risk management rule for the solvent methylene chloride (“MC”) on September 15, 2026.

“At every juncture of its scientific analysis, EPA has gone with the most extreme position,” the decision states. “EPA cannot justify the MC Rule in light of the TSCA’s requirements, the more demanding substantial-evidence standard that the TSCA requires, and the arbitrary and capricious standard.”

The ruling rejects policy positions developed under the Biden administration that were not defended by the Trump EPA. These include “whole chemical” risk determinations and the assumption that workers do not wear personal protective equipment (PPE)—policies EPA proposed to reverse in September 2025.

The ruling also addresses the meaning of “unreasonable risk,” the threshold for regulation under TSCA, by emphasizing that TSCA is not a zero-risk statute.

In addition to siding with industry-aligned petitioners, including the American Chemistry Council, the decision rejects a challenge from the Sierra Club that the MC rule is insufficiently protective.

The decision may implicate numerous previously conducted risk evaluations, which are already mired by delays. It also calls into question elements of EPA’s other risk management rules, including rules for carbon tetrachloride, perchloroethylene, and trichloroethylene, which are currently being litigated. EPA is reconsidering at least part of all three rules.

Finalized in 2024, the MC rule prohibits MC’s distribution for consumer use and most commercial uses. Uses not banned are subject to stringent workplace exposure limits. As discussed in a previous post, the Fifth Circuit appeared skeptical of EPA’s justifications for these restrictions during oral argument in June 2025.

“Whole Chemical” Approach and Assumption Workers do not Wear PPE

EPA completed its initial risk evaluation for MC in 2020 under the first Trump administration. The Biden EPA issued a revised risk evaluation in 2022. The revised evaluation replaced the initial evaluation’s condition-of-use-specific risk determinations with a determination that MC presents unreasonable risk “as a whole chemical substance.” Unlike the initial evaluation, the revision also assumed that exposed workers do not wear PPE. The panel held that both policy reversals were unlawful.

The court first examined the “whole chemical” approach. Emphasizing TSCA’s repeated use of the phrase “conditions of use” when describing how risk evaluations must be conducted, the court held that a whole-chemical determination exceeds EPA’s authority under the statute.

“There is no getting around the conclusion that the TSCA focuses on both determining and regulating risk according to the actual, separate ‘conditions of use’ for a given chemical or substance,” the decision states.

The court also found that EPA erred when issuing whole-chemical determinations under the Trump EPA’s regulations for risk evaluations, which the court held expressly require use-by-use determinations. Those regulations were replaced by the Biden EPA in 2024.

Turning to PPE, the court held that PPE use is encompassed by the definition of “conditions of use.” EPA justified its reversal on assumed usage by arguing that some workplaces may not be covered by OSHA standards or comply with OSHA requirements. But the court found that this position was undermined by the initial MC risk evaluation. There, EPA found some evidence of PPE use and concluded that PPE use was reasonably foreseeable because EPA had no basis to assume noncompliance with OSHA requirements.

The court also pointed to statements in EPA’s revised risk evaluation indicating that the policy change was not an indication of widespread OSHA noncompliance and that MC is subject to numerous regulations. Combined with EPA’s decision not to alter the exposure assessments in the revised risk evaluation, the court found that EPA’s explanations “are remarkably self-contradictory.”

EPA’s reversal was therefore contrary to law, arbitrary and capricious, and lacked substantial evidence, the court concluded.

The Fifth Circuit’s ruling aligns with changes EPA proposed in 2025. EPA’s proposed rule would require use-by-use risk determinations and eliminate language prohibiting the assumption of PPE use.

“Unreasonable Risk” and Exposure Limits

The industry petitioners’ central argument is that EPA treated any MC risk as unreasonable and regulated beyond what was required to remove unreasonable risk. The panel agreed, concluding that “EPA’s approach to ‘unreasonable risk’ was far more conservative than the statutory term connotes.”

TSCA is not a zero-risk statute, the court held, emphasizing that the word “unreasonable” “must allow for some risk.” Moreover, unlike other environmental statutes, TSCA does not incorporate a precautionary principle, the court noted.

The court also rejected EPA’s argument that unreasonable risk is a factual finding deserving judicial deference, describing it instead as a “legal conclusion” drawn from scientific findings.

The court then turned to the MC rule’s exposure limits, including a 16 ppm limit for acute exposures and a 2 ppm limit for chronic exposures. These limits “lack epidemiological support, reflect selective use of data and failures to consider alternative acceptable data, and were based on unrealistic benchmark margins of error,” the decision states.

“In sum, the risk analysis did not accord with the best available science as the TSCA requires, and the results more closely approximate the precautionary principle than the statute’s ‘unreasonable risk’ standard,” the court held.

According to the court, EPA calculated the acute exposure limit by taking a human study finding peripheral vision impairment at 478 ppm and dividing by thirty, in part to account for variability among humans. But EPA’s exclusive reliance on the study was problematic, the court held, because EPA did not show that another human study with less concerning results should be disregarded entirely. The court also noted the gap between the 16 ppm limit and the 2,300 ppm concentration EPA rated as “immediately dangerous,” as well as OSHA’s 125 ppm standard.

The court’s analysis of the 2 ppm chronic exposure limit was similar. EPA exclusively relied on a single imperfect animal study, improperly excluded results from human studies, and reached a chronic exposure limit less than one-tenth of OSHA’s, the court held.

Regulatory Response and Alternatives

Even if the exposure limits had been correctly derived, the court concluded that the rule would still regulate more than necessary to remove the unreasonable risk.

First, the panel rejected EPA’s decision to prohibit MC uses when it was unsure whether industrial and commercial users would be able to satisfy “dramatically reduced” limits. “EPA cannot simply ban a chemical substance whenever it is ‘uncertain’ whether a risk will remain reasonable,” the decision states.

Second, the court concluded that the rule did not meet TSCA’s command that EPA consider the availability of alternatives. The court held that EPA did not seriously consider numerous comments explaining the unavailability of alternatives. In addition, EPA repeatedly failed to consider economic, productivity, and environmental losses associated with the adoption of alternatives, the court held.

Excluding Exposures

A final key holding arose from the Sierra Club’s challenge. Among other arguments, the environmental group contends that EPA did not adequately consider air and drinking-water exposures. Those exposures were excluded from the scope of EPA’s risk evaluation, although EPA considered them in a subsequent, truncated analysis.

The panel was not persuaded, pointing to uncertainties EPA identified in the supplemental analysis. “We cannot say that EPA is prohibited from excluding exposure pathways and exposure types that it does not have a methodology to accurately assess,” the decision states. “A fair reading of the TSCA leaves ample latitude for EPA to exclude certain exposure pathways when the science or methodology is not developed.”

The Ninth Circuit has held that TSCA’s directive requiring EPA to publish risk evaluation scoping documents based on the conditions of use it “expects to consider” does not authorize EPA to exclude conditions of use. But the Fifth Circuit found that precedent inapposite because that case concerned EPA’s regulations governing the conduct of risk evaluations rather than a specific risk evaluation.

In a footnote, the court added that it did not necessarily agree with the Ninth Circuit’s reasoning, pointing to a separate provision of TSCA that might provide EPA with discretion.

That issue, too, is the subject of EPA’s proposed regulatory changes. EPA’s proposed revisions to the risk evaluation framework regulations would grant EPA discretion to exclude conditions of use and exposure pathways from risk evaluations.

The case is East Fork Enterprises v. Zeldin, No. 24-60227 (5th Cir.), filed May 10, 2024. Unless expedited, the court will issue its mandate November 7, 2026.

EPA Finds Unreasonable Risk in Four Draft TSCA Risk Evaluations

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In August and early September, EPA released draft risk evaluations for 1,2-dichloropropane, trans-1,2-dichloroethylene, o-dichlorobenzene (oDCB), and p-dichlorobenzene (pDCB) under the Toxic Substances Control Act (TSCA). EPA preliminarily determined that all four substances present unreasonable risk, driven primarily by certain conditions of use analyzed in the draft risk evaluations.

EPA will consider public comments before finalizing the evaluations. If EPA continues to find unreasonable risk, the agency will propose risk management actions under TSCA Section 6(a) to address those exposures.

1,2-Dichloropropane

1,2-Dichloropropane is an industrial chemical used in laboratory and industrial applications. According to EPA, it was previously used in cleaners, polishes, and waxes, and the Agency is evaluating those uses because imported products may still contain the substance. EPA has recognized 1,2-dichloropropane as likely to be carcinogenic to humans.

EPA’s draft evaluation identifies significant contributions to unreasonable risk to workers and occupational non-users from inhalation and dermal exposure under 11 conditions of use. Three consumer uses involving cleaners, polishes, and waxes were also preliminarily found to contribute to unreasonable risk. EPA did not identify unreasonable risk to the general population or the environment.

trans-1,2-Dichloroethylene

trans-1,2-Dichloroethylene is used in industrial and commercial cleaning and degreasing, as a processing aid, and in consumer products such as cleaners, degreasers, and foam insulation.

EPA’s draft evaluation identifies significant contributions to unreasonable risk to workers and occupational non-users from inhalation exposure under 19 conditions of use. One consumer use of trans-1,2-dichloroethylene—as a cleaner or degreaser—was also preliminarily found to contribute to unreasonable risk. EPA did not identify unreasonable risk to the general population or the environment.

oDCB and pDCB

oDCB and pDCB are used in household and commercial products and can evaporate into the air. pDCB is used in some air-care and deodorizing products, making indoor air a potential route of consumer exposure.

EPA’s draft evaluation for oDCB identifies contributions to unreasonable risk to workers from 14 conditions of use through inhalation, with dermal exposure contributing to risk in seven conditions of use. The draft also identifies unreasonable risk to consumers from one condition of use through inhalation.

For pDCB, EPA identified contributions to unreasonable risk to workers from seven conditions of use through inhalation and dermal exposure, as well as to consumers through inhalation from air-care products.

For both substances, EPA evaluated developmental, liver, and respiratory toxicity. EPA’s worker risk estimates do not assume the use of personal protective equipment (PPE), although the draft evaluations separately discuss how PPE and other controls could reduce exposure. EPA did not identify unreasonable risk to the general population through ambient outdoor air, including fenceline communities, or to the environment.

EPA’s draft evaluation for pDCB also concludes that the substance is not likely to be carcinogenic to humans. EPA acknowledges, however, that the International Agency for Research on Cancer and the National Toxicology Program have classified pDCB differently. EPA is specifically seeking comments and data on its assessment.

What This Means in the Context of EPA’s TSCA Evaluations

EPA is behind schedule on legally required risk evaluations under TSCA. In November 2024, EPA entered into consent decrees with the D.C. District Court concerning 22 risk evaluations, none of which were completed within TSCA’s 3.5-year deadline. The consent decrees created a court-enforceable schedule for EPA to complete the overdue evaluations.

The consent decrees have since been modified. In March 2025, EPA asked the court to extend by 60 days the deadlines for two draft risk evaluations and the final risk evaluation for 1,1-dichloroethane. The court granted the extensions on March 7, 2025.

The release of these four draft evaluations reflects EPA’s continuing effort to complete years-overdue TSCA risk evaluations under the court-ordered schedule established to address the Agency’s backlog.

Department of Defense Again Requests Information on TSCA-Prioritized Substances

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On May 12, 2026, the Department of Defense’s (DOD’s) Chemical and Material Risk Management Program issued a request for information (RFI) seeking industry data on defense and defense industrial base applications that rely on ten substances undergoing EPA’s Toxic Substances Control Act (TSCA) Section 6 risk evaluation process. The RFI is intended to help DOD better understand applications that require these chemicals and their importance to industry and defense supply chains.

The Risk Evaluation Process

The TSCA Section 6 risk evaluation process mandated by the 2016 Lautenberg amendments to TSCA provides a pathway for EPA to evaluate chemicals currently in commerce to determine whether they present an unreasonable risk to human health or the environment. Where such risks are identified, the agency is required to develop rules to protect human health and the environment. Regulation can range from improved workplace protections to bans on specific uses. For examples, see our previous posts on risk management rules for n-methylpyrrolidone (NMP) and 1-bromopropane.

The RFI is intended to help DOD better understand potential impacts of future TSCA regulation on military applications and defense supply chains. In particular, DOD is seeking information about how the substances are used, their importance to defense applications, quantities needed, and the availability of alternatives.

Substances Covered by the RFI

The RFI focuses on ten TSCA high-priority substances:

  • Phthalic anhydride (CASRN 85-44-9)
  • o-Dichlorobenzene (o-DCB) (CASRN 95-50-1)
  • p-Dichlorobenzene (p-DCB) (CASRN 106-46-7)
  • 4,4’-(1-Methylethylidene)bis[2,6-dibromophenol] (TBBPA) (CASRN 79-94-7)
  • Tris(2-chloroethyl)phosphate (TCEP) (CASRN 115-96-8)
  • Phosphoric acid, triphenyl ester (TPP) (CASRN 115-86-6)
  • 1,1,2-Trichloroethane (CASRN 79-00-5)
  • trans-1,2-Dichloroethylene (DCE) (CASRN 156-60-5)
  • Formaldehyde (CASRN 50-00-0)
  • Vinyl Chloride (CASRN 75-01-4)

EPA has finalized risk evaluations for some of these substances, including TCEP. For others, like phthalic anhydride, EPA has released a draft risk evaluation. Some, such as TPP and vinyl chloride, remain at the scoping stage.

The RFI is for information and planning purposes only. DOD intends to use the information to identify critical applications earlier in the TSCA Section 6 process, investigate the availability of alternatives, and better manage chemicals important to national defense.

Continued DOD Information Gathering

This is not DOD’s first RFI on substances undergoing TSCA risk evaluation. In May 2025, DOD issued an RFI seeking information on critical military uses of 11 other substances. That RFI similarly sought information about chemical applications, supply-chain importance, and potential alternatives. The 2026 RFI expressly states that it continues that information-gathering effort and covers a new group of ten TSCA high-priority substances.

Responses to the RFI were due June 19, 2026. However, DOD’s webpage states that companies may continue to submit responses to closed RFIs.

Industry Groups Tell Third Circuit That EPA’s TCE Exemption Is Unworkable

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Companies granted an exemption from EPA’s ban on trichloroethylene (TCE) are asking the Third Circuit to vacate key conditions of that exemption, arguing that the requirements are so stringent they defeat the exemption’s purpose under the Toxic Substances Control Act (TSCA).

The brief, filed May 13, 2026, is one piece of consolidated litigation in which industry groups, environmental organizations, and labor unions are contesting EPA’s TCE prohibition.  EPA has placed the delayed prohibitions for critical uses on hold pending resolution of the case.

The petitioners include a trade association, a manufacturer of a lead-acid battery component, and a company that produces a specialty material used in passports.  EPA granted exemptions to the TCE ban for both uses under TSCA section 6(g), which permits exemptions when compliance “would significantly disrupt the national economy, national security, or critical infrastructure.”

However, the exemption came with a stringent 0.2 parts per million (ppm) worker exposure limit—a threshold the petitioners argue violates TSCA’s requirement that exemption conditions still “achiev[e] the purposes of the exemption.”

Even with state-of-the-art controls, the petitioners contend that the interim existing chemical exposure limit (ECEL) would require workers to wear bulky, full-facepiece respirators at all times.  That level of PPE use is infeasible, they argue: some workers cannot wear it for medical reasons, it impedes communication, hearing, and movement, and it is intolerable to wear for an entire shift.

“EPA admits that respiratory PPE creates health and safety hazards, and the record demonstrates that respiratory PPE cannot feasibly be worn all day, every day, by employees in Petitioners’ manufacturing facilities,” the brief states.

“Petitioners will thus be unable to invoke the section 6(g) exemption and will have to shut down their operations in the United States—the very outcome the exemption was intended to avoid,” the petitioners allege.

The petitioners suggested alternative interim ECELs, including a limit aligning with the European Union and United Kingdom’s 6 ppm restriction, but say EPA “merely nodded at this figure without providing any reasoned analysis for rejecting it.”

Best Available Science

The petitioners also challenge the scientific basis for the 0.2 ppm threshold.  Their brief focuses on a rodent oral-exposure study that allegedly underpinned the interim ECEL, arguing it was methodologically flawed in multiple respects, including that its experimental and control groups were not run concurrently.  Most importantly, they argue, its linkage between low TCE exposures and congenital heart defects has not been replicated in a dozen other experiments.

“TSCA’s best-available-science requirement is meant to prevent precisely this kind of selective reliance,” the brief contends.

The petitioners also challenge EPA’s decision to limit the TCE exemption for lead-acid battery separator manufacturing to 20 years rather than the 25 years requested, arguing that the shorter duration was arbitrary.

The brief asks the court to vacate both the interim ECEL requirement and the 20-year cap on the battery-separator exemption.  (The exemption for TCE used to manufacture specialty polymeric microporous sheet materials runs for 15 years and is not at issue on this point).

The consolidated proceedings were formerly captioned United Steelworkers v. EPA, No. 25-1055 (3d Cir.).  The brief can be found in the docket for Microporous LLC v. EPA, No. 25-1080 (3d Cir.).

EPA Cannot Use Low Exposure to Justify DecaBDE Inaction, Ninth Circuit Rules

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The Ninth Circuit has ruled that EPA’s decisions not to regulate certain decabromodiphenyl ether (decaBDE) exposures under the Toxic Substances Control Act (TSCA) were not supported by substantial evidence, ordering the agency to regulate or better justify its inaction in four areas: recyclable articles, disposal, wastewater, and sewage sludge.

The May 13, 2026, ruling leaves EPA’s regulations for decaBDE intact but remands them back to agency to regulate—or better defend its decision not to regulate—those areas.  It is the first time a court has weighed in on TSCA section 6(h), which requires EPA to reduce exposures to certain persistent, bioaccumulative, and toxic chemicals (PBTs) “to the extent practicable.”

Congress added section 6(h) in 2016.  EPA issued a risk management rule for decaBDE in 2021 and amended it in 2024, targeting the flame retardant’s use in products.  But the agency declined to regulate various other exposures, citing low exposures and prohibitively high costs.

Siding with environmental groups, the Ninth Circuit rejected EPA’s low-exposure rationale outright.  Because TSCA does not require EPA to conduct a risk evaluation before regulating section 6(h) PBTs, Congress already determined that any exposure warrants a regulatory response, the court held.

“[I]t is beyond EPA’s authority to justify a decision not to regulate based on there being low levels of decaBDE,” the opinion states.  “TSCA § 6(h)(4) permits EPA to consider decaBDE levels for the purpose of deciding between regulatory tools, but not in deciding whether to use a regulatory tool at all.”

The court stopped short of holding that high costs can never justify a decision not to regulate under section 6(h), but it found EPA’s cost evidence consistently inadequate.  For recyclable articles, for example, EPA’s economic analysis relied on studies not specific to decaBDE and failed to consider regulatory options short of an outright ban.

Substantial Evidence

EPA’s other justifications fared no better under TSCA’s “substantial evidence” standard, which the court characterized as a “searching review.”

On disposal, EPA argued regulations were unnecessary because the Resource Conservation and Recovery Act (RCRA) already reduces exposures to the extent practicable.  But the court held that “EPA cannot evade its responsibilities under TSCA to regulate decaBDE disposal merely by invoking EPA’s compliance with another statute regulating solid waste disposal,” while also observing that RCRA does not cover all possible disposals.

For wastewater, the court found that EPA had ignored data contradicting its position that decaBDE is not released to water.  And, on recycling, it held that the agency gave “undue weight” to its position that regulation would undermine its general pro-recycling stance.

The court also rejected EPA’s fallback argument that staged regulation justifies its current inaction.  Section 6(h) “expressly places regulation of decaBDE on an expedited timeline,” the court held, and EPA has made no commitment to address these exposures in future rulemaking.

The case is Alaska Cmty. Action on Toxics v. United States EPA, No. 21-70168 (9th Cir.).

Trump Administration Proposes Overhaul of Biden-Era TSCA Risk Evaluation Framework

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On September 23, 2025, EPA published a proposed rule that would roll back key provisions of the agency’s May 2024 risk evaluation framework rule, which sets out the procedures EPA uses to assess the risks of existing chemicals under the Toxic Substances Control Act (TSCA).

According to EPA, the proposal is intended to “effectuate the best reading of the statute and ensure that the procedural framework rule does not impede the timely completion of risk evaluations or impair the effective and efficient protection of health and the environment.”

The rollback is a priority for the Trump administration, which first announced its intent to reconsider the rulemaking in March.  The 2024 rule—itself a revision of a rule issued during the first Trump administration—has been criticized by industry groups such as the American Chemistry Council and targeted for revision by the Heritage Foundation’s “Project 2025” initiative.

What Changes is EPA Proposing?

If finalized, the rule would:

  • Grant EPA discretion to narrow the scope of risk evaluations by excluding conditions of use and exposure pathways from its assessments.
  • Require that separate risk determinations be made for each of a chemical’s conditions of use, instead of a single risk determination for the chemical as a whole.
  • Remove language prohibiting EPA from assuming worker protections through PPE usage.
  • Eliminate “overburdened communities” from the list of “potentially exposed or susceptible subpopulations” that must be considered in evaluations.
  • Provide EPA with greater flexibility to revise or supplement scope or risk evaluation documents without restarting the prioritization process.
  • Scale back information collection requirements for manufacturers requesting a risk evaluation.
Stakeholder Responses

The proposal has drawn criticism from environmental groups, who warn that the changes—particularly EPA’s ability to exclude conditions of use and exposure pathways—will jeopardize public health.

“Rather than looking at the full picture of a chemical’s toxic risk, EPA wants to downplay the links these chemicals have to cancer and chronic disease and give the chemical industry a handout at the expense of our health and safety,” an Environmental Defense Fund official said in a statement.

“The chemicals in the pipeline for review under TSCA have been prioritized specifically because of the risks they pose to our health, and rewriting this process to lowball risks will only rig the rules to benefit the chemical industry,” she continued.

The American Chemistry Council, on the other hand, applauded the move.  “This proposed approach demonstrates EPA’s commitment to refining its processes in a way that is both protective and practical,” an official said in a press release.  “The proposal reflects meaningful progress toward a more science-driven regulatory framework for conducting TSCA risk evaluations.”

Comments on the proposed rule are due November 7, 2025.  More on the 2024 rule can be found here.

EPA Requests Comment on Reconsideration of PCE Rule

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On July 30, 2025, EPA published a request for comment as it reconsiders its regulation of perchloroethylene (PCE) under the Toxic Substances Control Act (TSCA).  The request marks the first step toward potentially amending the rule issued in December 2024, which prohibited or phased out most uses of the solvent.

EPA is particularly interested in receiving comment on:

  • Whether the existing chemical exposure limit of 0.14 parts per million (ppm) should be replaced by a different limit, such as the non-cancer exposure limit of 0.5 ppm or the lifetime cancer exposure limit of 0.47 ppm;
  • Conditions of use that may be better managed through workplace protections rather than bans; and
  • Use of PCE in industrial dry cleaning processes, including workplace controls and the performance of alternatives in those operations.

EPA first announced its intent to revisit the rule in a May 12 motion requesting that the Fifth Circuit place a consolidated legal challenge to the regulation on indefinite hold.  The court denied that request, instead granting a 90-day stay.

The PCE rule was primarily driven by concerns over the solvent’s neurotoxicity.  It bans all consumer uses of PCE as well as many industrial and commercial uses, including a 10-year phaseout for use in dry cleaning.  Many of the uses that are not prohibited, such as use in aircraft and petrochemical manufacturing, will be subject to workplace exposure controls.

According to EPA’s May 12 filing, any revisions to the rule are expected to take 12 to 18 months.  Comments on the notice are due August 29, 2025.

EPA Finalizes TSCA Risk Evaluation for Solvent 1,1-Dichloroethane

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EPA has determined that 1,1-dichloroethane presents an unreasonable risk of injury to human health in its final Toxic Substances Control Act (TSCA) risk evaluation for the chlorinated solvent, released June 20, 2025.

The agency identified worker risks from three specific conditions of use (COUs): processing for recycling, and processing as a reactant as an intermediate in certain chemical and chemical product manufacturing.  Five other evaluated COUs did not significantly contribute to the risk determination, and the agency did not identify unreasonable risks to the general public or the environment.

The evaluation found that exposure to 1,1-dichloroethane may increase the risk of non-cancer renal, olfactory, and reproductive effects, as well as tumor formation, based on hazard read-across data from 1,2-dichloroethane, an isomer of the solvent.

Because EPA determined that 1,1-dichloroethane presents an unreasonable risk, the agency is statutorily required to issue a final rule that mitigates those risks within two years, with up to two years of extensions possible.

Narrowed Findings

Notably, the final risk evaluation reached significantly less conservative conclusions about 1,1-dichloroethane’s risks than the draft risk evaluation, released in July 2024.  The draft found that seven COUs significantly contributed to the determination instead of three, and identified unreasonable risks to the environment based on risks to algae and invertebrates.

Among the changes made in the final risk evaluation were revisions to the “considerations of risk factors” for repackaging and disposal, use of “central tendency instead of the high-end for dermal exposure” for all COUs, and the incorporation of “considerations of personal protective equipment (PPE) use.”

According to EPA, 1,1-dichloroethane is primarily used to produce other chlorinated solvents with “broad industrial applications.”  The final risk evaluation notes that, in 2020, between 200 million and one billion pounds were manufactured by two corporations in the Southern US, with none imported.

More information on the risk evaluation can be found on EPA’s website.

DOD Requests Information on Chemicals Undergoing TSCA Risk Evaluation

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Last month, the Defense Department (DOD) issued a request for information (RFI) seeking input on critical military uses of 11 chemicals currently undergoing Toxic Substances Control Act (TSCA) risk evaluation.

The “ability to identify critical applications earlier in the TSCA Section 6 risk evaluation process will allow [DOD] to investigate the availability of alternatives, inform industry and interagency engagement, and better manage chemicals critical to national defense,” the RFI states.

DOD will likely use the information it collects to help ensure that critical applications are protected in any future TSCA risk management rule.

The 11 chemicals include 1,3-Butadiene, 1,1-Dichloroethane, 1,2-Dichloroethane, D4, and seven phthalates: BBP, DBP, DCHP, DEHP, DIBP, DIDP, and DINP.  Some, like DIDP, have finalized risk evaluations.  For others, such as D4, EPA has yet to release a draft.

The RFI focuses on identifying specific DOD applications that require these substances and their industrial criticality.  It asks for details such as annual usage quantities, whether viable alternatives exist, and which TSCA condition of use best matches each application.

According to the RFI, DOD currently relies on safety data sheets (SDSs) for chemical ingredient data, which contain limited information.  As a result, DOD “lacks visibility in tracking upstream applications to understand the implications of developing regulatory drivers, such as TSCA.”

Responses to the RFI were due June 20, but DOD will consider late comments to the extent practicable.  The department also stated that it “will continue to issue RFIs to consider additional TSCA chemicals.”

Fifth Circuit Questions EPA’s Methylene Chloride Rule in Landmark TSCA Case

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On June 3, 2025, the Fifth Circuit heard oral argument in a case consolidating industry and Sierra Club challenges to EPA’s regulation of methylene chloride under the Toxic Substances Control Act (TSCA).  The panel generally appeared to doubt EPA’s justification for banning certain uses of the solvent and imposing stringent workplace restrictions.

The background for East Fork Enterprises Inc. v. EPA, No. 24-60256, is discussed in a previous blog post.  It looks likely that this will be the first case in which a court of appeals rules on the merits of a TSCA risk management rule since EPA was granted expanded authority to regulate existing chemicals with the 2016 Lautenberg amendments to TSCA.

Undefended Policies

The industry petitioners’ attorney urged the court to rule on two Biden-era policies that the Trump EPA has declined to defend: the agency’s decision not to assume that workers use PPE, and its “single determination” approach to findings of unreasonable risk.

One judge asked the industry attorney whether there had been any statistical surveys or epidemiological work to determine the number of workers affected by methylene chloride, suggesting that EPA should base its review in terms of “reality.”  The industry attorney replied that isolated incidents were noted in the record, but that they should be considered against the size of the country.  “That there have been a given number of incidents is not enough to tell you the scale of the risk,” he said.

When a judge suggested that EPA’s use of conservative “uncertainty factors” helps the agency extrapolate from human studies in a way that “protect[s] those…most at risk,” the industry attorney pushed back.  “The uncertainty factors are going far beyond that…it is protective factor times protective factor times protective factor, and they’re doing that in a part of the analysis that is quite separate from what they’re doing for vulnerable populations,” he said.

Another judge inquired about the economics of the methylene chloride industry, claiming that “it’s not irrelevant to understand what the scope of the market is” when determining whether a regulation is reasonable.

Scientific Evidence

To defend its decision to impose significantly stricter worker exposure limits than OSHA, EPA argued that OSHA’s standard was based on cancer findings, rather than “the most common adverse effect, adverse liver effects.”  This drew pushback from one judge, who claimed that liver effects had only been found in animals, not humans.

“If you’re going to really show that there’s toxicity to the liver, it seems to me that you have to show toxicity to the liver, and that requires epidemiological testing, doesn’t it?” the judge said.  “EPA is tasked with finding unreasonable risk, and unreasonable risk, from a scientific standpoint, when you’re talking about humans, is epidemiology.”

EPA’s attorney acknowledged that “human studies are the first place you look” but said that “when [EPA doesn’t] have concrete information, they have to look [to] animals.”  Earlier in the argument, EPA’s attorney noted that animal testing allows for dissection, unlike human studies—which she argued can make some effects, like the early stages of liver disease, more apparent.

Both EPA and Sierra Club also pointed to the Lautenberg amendments’ explicit directive that EPA consider worker risks as evidence that Congress did not intend for EPA to defer to OSHA’s existing limitations.

“I Survived”

In a notable exchange, one judge expressed concern with the breadth of the risk management rule: “It’s hard to say that any party can verify that they have never given a bit of methylene chloride to their friend who’s refinishing old furniture, a subject for which I’m particularly sensitive, because I’ve done it, and I survived.”

EPA’s attorney replied that the rule permits continued use of methylene chloride for furniture refinishing for another five years because no adequate alternative currently exists.  “This is not a case where EPA was just unilaterally deciding, ‘we don’t like this chemical, we’re going to regulate so there’s zero risk,’” she said.

EPA was also sharply pressed on the applicable standard of review.  “We noticed that EPA’s brief didn’t cite a single case that relied on the substantial evidence standard [used by TSCA] as opposed to the lower arbitrary and capricious standard,” a judge observed.

Sierra Club Arguments

The panel also appeared skeptical about the Sierra Club’s arguments, which claim that EPA’s regulations did not properly protect fenceline communities or address risks to the ozone layer.

“It’s a very, very, very, stringent regulation…I mean, what do you mean?” one judge asked.

When EPA noted that methylene chloride emissions are regulated under the Clean Air Act, one judge asked, “How does Sierra Club have a justification for coming in on this regulation at all, vis-à-vis fenceline communities, because this regulation does not cover ambient air emissions?”

EPA’s attorney responded that this was why risks to fenceline communities were not evaluated in the original 2020 risk evaluation for methylene chloride—though those risks were considered in a 2022 revision.

During rebuttals, the Sierra Club was also pressed about EPA’s one-in-a-million cancer benchmark.  “One in a million is pretty darn small…where’s the science that supports one in a million of anything being unreasonable?” one judge asked.

The Sierra Club’s attorney said that the benchmark was supported by the Science Advisory Committee on Chemicals (SACC), prompting the judge to respond, “We did a little looking at that, and it looked like some…members of the [SACC] had also themselves received EPA grants.”

But the Sierra Club argued that it does create a conflict of interest, because other members had been funded by methylene chloride manufacturers.  “I think EPA aims for a diverse range of views on the SACC,” its attorney said.