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April 25, 2023

EPA Will Propose to Prohibit Most Uses of Methylene Chloride under TSCA Section 6(a)

Bergeson & Campbell, P.C.

On April 20, 2023, the U.S. Environmental Protection Agency (EPA) announced the release of a proposed rule under Section 6(a) of the Toxic Substances Control Act (TSCA) that would prohibit most uses of methylene chloride. EPA states that its unreasonable risk determination for methylene chloride was driven by risks associated with workers, occupational non-users (ONU), consumers, and those in close proximity to a consumer use. EPA identified risks for adverse human health effects, including neurotoxicity, liver effects, and cancer from inhalation and dermal exposures to methylene chloride. According to EPA, its proposed risk management rule would “rapidly phase down” manufacturing, processing, and distribution of methylene chloride for all consumer uses and most industrial and commercial uses, most of which would be fully implemented in 15 months. EPA notes that for most of the uses of methylene chloride that it will propose to prohibit, its analysis found that alternative products with similar costs and efficacy to methylene chloride products are generally available. Publication of the proposed rule in the Federal Register will begin a 60-day comment period.

According to the pre-publication version of the proposed rule, pursuant to TSCA Section 6(b), EPA determined that methylene chloride presents an unreasonable risk of injury to health, without consideration of costs or other non-risk factors, including an unreasonable risk to potentially exposed or susceptible subpopulations identified as relevant to the 2020 methylene chloride risk evaluation, under the conditions of use (COU). To address the unreasonable risk, EPA will propose, under TSCA Section 6(a) to:

  • Prohibit the manufacture, processing, and distribution of methylene chloride for all consumer use;
  • Prohibit most industrial and commercial use of methylene chloride;
  • Require a workplace chemical protection program (WCPP), including inhalation exposure concentration limits and related workplace exposure monitoring and exposure controls, for ten conditions of use of methylene chloride (including manufacture; processing as a reactant; laboratory use; industrial or commercial use in aerospace and military paint and coating removal from safety-critical, corrosion-sensitive components by federal agencies and their contractors; industrial or commercial use as a bonding agent for acrylic and polycarbonate in mission-critical military and space vehicle applications, including in the production of specialty batteries for such by federal agencies and their contractors; and disposal);
  • Require recordkeeping and downstream notification requirements for manufacturing, processing, and distribution in commerce of methylene chloride;
  • Provide a ten-year time-limited exemption under TSCA Section 6(g) for civilian aviation from the prohibition addressing the use of methylene chloride for paint and coating removal to avoid significant disruptions to critical infrastructure, with conditions for this exemption to include compliance with the WCPP; and
  • Provide a ten-year time-limited exemption under TSCA Section 6(g) for emergency use of methylene chloride in furtherance of the National Aeronautics and Space Administration’s mission for specific conditions which are critical or essential and for which no technically and economically feasible safer alternative is available, with conditions for this exemption to include compliance with the WCPP.

EPA notes that all TSCA COUs of methylene chloride (other than its use in consumer paint and coating removers, which was subject to separate action under TSCA Section 6 (84 Fed. Reg. 11420, March 27, 2019)) will be subject to this proposal. According to EPA, TSCA defines COU to mean the circumstances under which a chemical substance is intended, known, or reasonably foreseen to be manufactured, processed, distributed in commerce, used, or disposed of. EPA requests public comment on all aspects of this proposal.

WCPP for Methylene Chloride

According to EPA’s press release, EPA consulted with the Occupational Safety and Health Administration (OSHA) while developing the proposed rule “and was mindful of existing OSHA requirements in building out the proposed worker protections.” EPA states that its proposed risk-based limits are based on recent data and meet the TSCA requirement to eliminate the unreasonable risk. After EPA issues the final risk management rule, employers would have one year to comply with the WCPP and would be required to monitor their workplace periodically to ensure that workers are not being exposed to levels of methylene chloride that would lead to an unreasonable risk.

EPA “encourages members of the public to read and comment on the proposed rule.” EPA states that it is “especially interested in hearing perspective on the feasibility and efficacy of the proposed requirement for worker protections from entities that would be required to implement the proposed program.” According to EPA, in the coming weeks, it will host a public webinar targeted to employers and workers, “but useful for anyone looking for an overview of the proposed regulatory action to discuss the proposed program.” EPA will announce the date, time, and registration information “soon.”


Bergeson & Campbell, P.C. (B&C®) anticipated the direction of EPA’s proposed regulatory action and primary alternative regulatory options on methylene chloride. EPA’s proposed rule is consistent with its proposals in the draft proposed risk management rule on chrysotile asbestos, including the proposed regulatory action with prohibiting uses, primary alternative regulatory options with time-limited uses under TSCA Section 6(g) (e.g., national security and critical infrastructure), and proposing existing chemical exposure limits (ECELs) that are significantly lower than existing occupational exposure limits. Below, we have summarized several issues that members of the regulated community should consider when preparing public comments on the draft proposed rule, along with several reminders of the importance of early engagement with EPA on non-regulatory initiatives that can later inform regulatory activities under various statutes, including TSCA.

We were not surprised to see that EPA’s proposed regulatory action was to “prohibit most industrial and commercial uses of methylene chloride,” given its new policy direction using a “whole chemical” approach. EPA did, however, provide a primary alternative regulatory option that would allow some of the proposed prohibited conditions of use to continue, subject to compliance with a WCPP. We mention this because the language under TSCA Section 6(a) states that EPA should apply requirements for addressing unreasonable risks “to the extent necessary so that the chemical substance or mixture no longer presents such risk.” If a WCPP with an ECEL is protective of health and the environment, as EPA contends, it would appear that bans for certain uses would go beyond the “extent necessary” provision. The existing ban on consumer uses would still be justified even if a WCPP is protective because consumers would likely be unable to demonstrate and document compliance with the protective measures in a WCPP. On the other hand, if a workplace can demonstrate and document compliance with a WCPP, it seems that such a use should be allowed to continue.

As part of the WCPP requirements, EPA stated that it would require “Compliance with the Good Laboratory Practice Standards [GLP] at 40 CFR Part 792.” This requirement is inconsistent with most workplace monitoring work that is conducted to Industrial Hygiene Laboratory Accreditation Program (IHLAP) standards. EPA’s expectation of GLP testing for workplace monitoring is consistent with test orders issued in 2021, but inconsistent with its standard consent orders. For example, EPA’s TSCA Section 5(e) order template states the following under Section III.D:

Compliance with TSCA GLP[s], however, is not required under this New Chemical Exposure Limit Section where the analytical method is verified by a laboratory accredited by either: the American Industrial Hygiene Association (“AIHA”) Industrial Hygiene Laboratory Accreditation Program (“IHLAP”) or another comparable program approved in advance in writing by EPA.

EPA requested comment on specific aspects of the proposed rule that B&C encourages potentially impacted parties to consider. For example, EPA discussed its authority under TSCA Section 6(g) to grant a time-limited exemption for specific conditions of use (e.g., civilian aviation), where EPA finds that compliance with the proposed requirement would “significantly disrupt … critical infrastructure.” We note that this exemption would include compliance with the WCPP. Again, if the WCPP is protective and facilities are capable of complying with the WCPP (e.g., chronic non-cancer ECEL of 2 parts per million (ppm) and short-term exposure limit (STEL) of 16 ppm), the time limit seems to go beyond what is required to protect health and the environment. In our view, the exemption authority is to be used when protective measures do not sufficiently address the risks and a ban would significantly disrupt a critical sector (e.g., defense, aerospace, infrastructure). EPA seems to be taking an approach similar to that in the European Union under the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulations, in which a hazardous substance is to be banned except for limited circumstances, even if protective measures are adequate. While this approach may have general appeal, in our view, it does not comply with EPA’s Section 6 authority. If Congress had intended amended TSCA to work like REACH, Congress would have adopted that model, and it clearly did not.

EPA cited throughout the proposed rule to a 2022 document titled “An Alternatives Assessment for Use of Methylene Chloride” (i.e.Ref. 40 in the proposed rule). Based on this assessment, EPA stated that it “identified products containing ingredients with a lower hazard screening rating than methylene chloride for certain endpoints, while some ingredients presented higher hazard screening ratings than methylene chloride (Ref. 40).” As of the date of this commentary, EPA has not uploaded this document to the rulemaking docket, nor has EPA made the document available on its Health & Environmental Research Online (HERO) database. Without being able to review the details of this document, it is impossible to evaluate whether alternatives will work in every use. An alternative for paint stripping may not work as a solvent, for example, for cleaning sensitive electronic components of an aircraft.

We mention the absence of the above document because entities impacted by EPA’s proposed prohibition will need this information to determine the technical feasibility of alternatives, to gauge the potential risks of suitable alternatives that may undergo future regulatory action under TSCA, and to prepare public comments. We note that EPA discussed a comparable “alternatives” issue in its proposed rule on chrysotile asbestos, which included EPA’s intent to prohibit use of chrysotile asbestos in diaphragms used in the chlor-alkali industry. EPA acknowledged “that substitute technologies for asbestos-containing diaphragms in chlor-alkali production use an increased concentration of per- and polyfluoroalkyl substances (PFAS) relative to the amount of PFAS compounds contained in asbestos-containing diaphragms,” but did not further compare the potential hazards and risks of the alternatives.

Aside from the above risk management issues, we believe a significant legal vulnerability remains in EPA’s underlying risk evaluation on methylene chloride. As we discussed in our November 11, 2022, memorandum, EPA consistently refers to its use of the 2018 document titled “Application of Systematic Review in TSCA Risk Evaluations” (hereinafter the “2018 SR Document”) as the basis for satisfying its requirements for using the best available science and weight of scientific evidence under TSCA Sections 26(h) and (i), respectively. For example, EPA stated the following in the proposed rule on methylene chloride:

EPA considers the methylene chloride ECEL to represent the best available science under TSCA section 26(h), since it was derived from information in the 2020 Risk Evaluation for Methylene Chloride, which is the result of a rigorous systematic review process that investigated the entirety of the reasonably available current literature in order to identify all relevant adverse health effects. [emphasis added]

As we have written previously, the U.S. National Academies of Science, Engineering, and Medicine (NASEM) reviewed the 2018 SR Document at EPA’s request and concluded that:

The OPPT approach to systematic review does not adequately meet the state-of-practice [and] OPPT should reevaluate its approach to systematic review methods, addressing the comments and recommendations in this report.

We remind readers that TSCA Section 26(h) requires EPA to make decisions under TSCA Sections 4, 5, and 6 consistent with the best available science, which includes protocols and methodologies like systematic review. Further, EPA’s use of the 2018 SR Document in the final risk evaluation for methylene chloride also casts doubt on whether EPA met the requirements for weight of scientific evidence under TSCA Section 26(i), which EPA codified to mean a “systematic review method, applied in a manner suited to the nature of the evidence or decision ….”

EPA’s two proposed regulations under TSCA Section 6(a) (i.e., chrysotile asbestos and methylene chloride) provide some insight on the direction that EPA will take on the proposed risk management rules for the remaining first ten chemical substances where EPA found unreasonable risks for conditions of use in the final risk evaluations. Industries that use these substances should prepare for forthcoming prohibitions, WCPPs, or time-limited exemptions that require compliance with WCPPs. B&C encourages interested parties to review the proposed regulation on methylene chloride even if readers do not use methylene chloride and to provide comments as appropriate, recognizing that the proposed risk management options on methylene chloride will likely be the standard for EPA’s forthcoming proposed regulations on other existing chemical substances with final risk evaluations (e.g., 1-bromopropane, carbon tetrachloride, 1,4-dioxane, perchloroethylene, and trichloroethylene).