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August 5, 2021

EPA Will Delay 1,4-Dioxane Risk Management until Nearing Completion of Reconsideration of Risk Evaluation

Bergeson & Campbell, P.C.

In a July 30, 2021, filing in the U.S. Court of Appeals for the Ninth Circuit, the U.S. Environmental Protection Agency (EPA) states that it cannot “meaningfully commence” risk management rulemaking for 1,4-dioxane until it nears completion of its reconsideration of the final risk evaluation. EPA released the final risk evaluation for 1,4-dioxane on January 8, 2021, in the final weeks of the Trump Administration. On June 30, 2021, the Biden-Harris EPA announced several policy changes regarding risk evaluations issued under the Toxic Substances Control Act (TSCA) and the path forward for the first ten chemicals to undergo risk evaluation. According to the announcement, EPA intends to re-open and update the 1,4-dioxane risk evaluation to consider whether to include additional exposure pathways and conditions of use that were excluded from the supplemental and final risk evaluations.


The final risk evaluation for 1,4-dioxane identifies unreasonable risk to workers for 13 out of 24 conditions of use. According to the final risk evaluation, EPA found no unreasonable risk to the general population and the environment. EPA published a supplemental analysis to the draft risk evaluation that evaluated eight additional conditions of use for 1,4-dioxane present as a byproduct in consumer products. According to EPA, after “carefully considering” public comments on the supplemental analysis, it found no unreasonable risk for these consumer uses. More information on the final risk evaluation is available in our January 13, 2021, memorandum, “Final Risk Evaluation for 1,4-Dioxane Finds Unreasonable Risk to Workers for Certain Uses.”

In a February 4, 2021, update on chemical safety actions, the Biden-Harris EPA stated that it intended to review the final risk evaluations for the first ten chemicals, including 1,4-dioxane, while immediately beginning the risk management process. Several months later, in a June 22, 2021, press release marking the fifth anniversary of the Frank R. Lautenberg Chemical Safety for the 21st Century Act amendments to TSCA, EPA provided more detail on its review of the final risk evaluations. This includes reconsidering certain approaches and assumptions used for risk evaluations under the prior Administration, including assumptions on worker use of personal protective equipment (PPE), developing a process for ensuring all routes of exposure to a chemical are included in risk evaluations, and making risk evaluations more comprehensive by ensuring potentially exposed or susceptible subpopulations are appropriately included. At the same time, EPA intended to move “expeditiously” to risk management for the first ten chemicals to undergo risk evaluation, “taking into account the reconsideration of some policy decisions made under the previous Administration to ensure the rules are fully protective of both health and the environment.”

EPA’s June 30, 2021, announcement provides more information on the policy changes EPA is making regarding risk evaluations. According to the announcement, EPA intends to re-open and update the 1,4-dioxane risk evaluation to consider whether to include additional exposure pathways, such as drinking water and ambient air, and conditions of use where 1,4-dioxane is generated as a byproduct that were excluded from the supplemental and final risk evaluations. EPA will release the revised risk evaluation for public comment before issuing it in final. EPA is revisiting its assumption that PPE is always used in occupational settings when making risk determinations. According to EPA, because the first ten risk evaluations included exposure analysis with and without PPE, removing this assumption does not create a need for new analysis. The revision could change some of the conclusions about risk on some conditions of use for which “no unreasonable risk” findings were made, including for 1,4-dioxane. In addition to reconsidering these assumptions, EPA intends to revise its approach in its first ten risk evaluations, including 1,4-dioxane, regarding its issuance of risk determinations for each condition of use. Instead, EPA intends to issue revised risk evaluations to make one determination of unreasonable risk for the chemical as a whole, using the “whole chemical approach.”


Following EPA’s publication of the 1,4-dioxane risk evaluation, environmental and labor groups and a coalition of state and municipal governments filed five petitions for review challenging EPA’s 11 determinations of no unreasonable risk. These petitions were filed in or transferred to the U.S. Court of Appeals for the Ninth Circuit and consolidated in Environmental Defense Fund (EDF), et al. v. EPA, Case No. 21-70162 (filed January 27, 2021), which consolidated Case Nos. 21-70194, 21-70684, 21-70727, and 21-70930.

On June 8, 2021, EPA filed a voluntary motion for remand of the risk evaluation without vacatur. EPA’s motion preceded the filing of opening briefs on the merits in the consolidated cases. EPA argues that remand is warranted as EPA intends to reconsider the determinations of no unreasonable risk and revisit the legal, scientific, and policy assumptions and approaches it made when conducting the 1,4-dioxane risk evaluation. EPA notes that the reconsideration may result in a new or different administrative record, therefore, in addition to allowing EPA to exercise its discretion in revisiting its interpretation of TSCA and implementation of the 1,4-dioxane risk evaluation, remand would also serve the interests of judicial economy.

In support of EPA’s plan to revisit the assumptions and approaches in its risk evaluations, EPA cites Executive Order No. 13,990, entitled “Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis,” issued by the Biden Administration on January 20, 2021. This Executive Order requires EPA to reconsider past actions to ensure the Agency is meeting goals such as listening to science, improving public health, establishing protections for the environment, ensuring access to clean air and water, limiting exposure to dangerous chemicals and pesticides, and prioritizing environmental justice. EPA asserts that its reconsideration of the 1,4-dioxane risk evaluation is consistent with this policy.

The State and Municipal Petitioners and the Environmental and Labor Petitioners submitted responses taking no position on or opposing EPA’s motion for voluntary remand, respectively, on July 9, 2021. In both responses, the petitioners request that if the court grants remand, that the court vacate EPA’s 11 determinations of no unreasonable risk and impose conditions upon EPA, such as requiring status reports and enforceable time limits for the reconsideration. Both responses also expressed concerns that while EPA committed to conducting a reconsideration, EPA did not commit to enacting specific changes or admit to any errors in the risk evaluation.

EPA addressed these arguments in its July 30, 2021, reply in support of its motion for voluntary remand. EPA states that the imposition of deadlines or other restrictions on remand would “impair EPA’s flexibility to address public comments or other issues that arise during reconsideration.” EPA would agree to file 90-day status reports during the remand. EPA reiterated that it intends, in good faith, to reconsider the risk evaluation, but is not required to commit to any change in approach or a confession of error to secure a voluntary remand.

EPA’s request for remand of the 1,4-dioxane risk evaluation follows two similar motions for voluntary remand of the methylene chloride and hexabromocyclododecane (HBCD) risk evaluations before the Ninth Circuit. EPA requested voluntary remand without vacatur in these Ninth Circuit cases (Neighbors for Environmental Justice et al. v. EPA, Case Nos. 20-7209, 20-73276 and Alaska Community Action on Toxics v. EPA, Case Nos. 20-73099, 20-73578, 21-70009) in May 2021.

On July 14, 2021, the Ninth Circuit granted EPA’s motion for voluntary remand without vacatur of the methylene chloride risk evaluation. The court will hold the case in abeyance until EPA concludes the reconsideration process. The court declined to impose the time limitations or other conditions requested by the petitioners, but will require EPA to file status updates every 90 days. In its June 18, 2021, reply in support of its remand motion, EPA outlined a proposed schedule for the reconsideration, estimating that it will issue a revised risk determination at earliest in August 2022. EPA did not address whether it would develop risk management rules for methylene chloride concurrently in its reply, but noted that EPA must make a new risk determination under TSCA Section 6(b)(4) for the six conditions of use under reconsideration prior to undertaking a risk management rulemaking for these uses under TSCA Section 6(a).

The court has not yet decided EPA’s motion in the HBCD case. EPA filed a reply in support of its voluntary remand motion on July 9, 2021. Unlike the methylene chloride and 1,4-dioxane risk evaluations, however, EPA intends to issue a revised risk determination for the chemical as a whole between July 2021 and August 2021 and a final risk determination by November 2021, while developing concurrently a risk management rule for HBCD.


Going forward, the Ninth Circuit will likely grant EPA’s motion for voluntary remand of its determinations of no unreasonable risk without vacatur and may similarly require that EPA file status reports with the court every 90 days. As EPA has committed to revising the risk evaluations for 1,4-dioxane and the other first ten chemicals, the information available on EPA’s projected timeline and reconsideration plans, as well as the impact on the reconsiderations on risk management, have continued to evolve.

EPA’s court filings in the 1,4-dioxane, methylene chloride, and HBCD cases and public announcements indicate that the estimated completion dates for the revised risk evaluations, and their impact on risk management rulemaking, will vary for each of the first ten chemicals and will continue to evolve. For 1,4-dioxane, EPA’s July 30, 2021, statements dispel the notion that EPA would develop risk management rules concurrently with the reconsideration of the risk evaluation for this substance, noting that the issues are too “implicitly intertwined” to begin risk management until the reconsideration process nears completion. EPA signals that, once complete, EPA will “work expeditiously to complete risk management rulemaking as soon as possible.” At present, EPA estimates that the reconsideration process will conclude in 18 months, or by December 2022.