On September 15, 2026, the U.S. Court of Appeals for the Fifth Circuit vacated the United States Environmental Protection Agency’s (U.S. EPA) Toxic Substances Control Act (TSCA) Methylene Chloride (MC) Regulation and the associated risk determination. The MC Regulation was vacated because the Court determined that U.S. EPA does not have authority to make whole chemical risk determinations that regulate every use, and that U.S. EPA made unreasonable assumptions in its risk determinations, including a universal assumption that personal protective equipment (PPE) was not used by workers exposed to MC.
How did we get here?
The TSCA provides U.S. EPA the authority to regulate chemicals throughout commerce, by requiring approval, reporting, record-keeping, and testing requirements for industrial chemicals. In 2016, TSCA was amended by Congress through the Frank R. Lautenberg Chemical Safety for the 21st Century Act that required U.S. EPA to begin priority risk evaluations for certain chemicals to identify and quantify unreasonable risk under Section 6. One chemical identified for evaluation was MC and during the evaluation, U.S. EPA determined it posed an unreasonable risk. On May 8, 2024, the Final Risk Management Rule was published and U.S. EPA banned MC for all consumer uses, allowed MC in very limited industrial and commercial uses (40 of 53 uses were banned), and required a comprehensive Workplace Chemical Protection Program (WCPP) for the allowable 13 industry uses. With the Final Risk Management Rule publication, U.S. EPA acknowledged that the rule would greatly impact antique architectural work and commercial furniture refinishing but failed to make exceptions for the industries. The WCPP requirements imposed strict exposure limitations for acute exposure and chronic exposure.
Petitions for review were filed by an industry group (American Chemistry Council, East Fork Enterprises, and Epic Paint Company) and the Sierra Club. The Industry Petitioners argued that U.S. EPA overstepped their authority, while the Sierra Club argued U.S. EPA had not gone far enough to protect people who live in communities adjacent to factories emitting MC, have cancer-favoring genetics, or live at altitudes where ozone depletion is a concern. The case was argued in 2024.
What did the Fifth Circuit Court decide?
First, they evaluated U.S. EPA’s authority to make the whole chemical risk determination for MC. The Fifth Circuit Court determined U.S. EPA lacked authority to make a such a determination. The TSCA and U.S. EPA’s procedural rules both require a separate risk determination for each condition of use. Instead, U.S. EPA contradicted its own procedural rule and the TSCA procedural rule by making a whole chemical interpretation in the revised risk determination in November 2022. Prior to this revised risk determination, U.S. EPA was following the procedural and TSCA rules mandating a separate risk determination for each use of the chemical.
Second, the Fifth Circuit Court examined whether U.S. EPA violated TSCA in the revised risk determination by assuming workers were not using PPE when working with MC. The court determined that U.S. EPA violated TSCA and acted without supporting evidence by stating that workers were not using PPE. TSCA mandates that U.S. EPA must account for PPE in risk evaluations, provided evidence shows PPE is used. The final risk evaluation in 2020 illustrated that appropriate PPE use was a condition for using MC in industrial and commercial applications before reversing course in the November 2022 Revised Risk Determination. In addition, U.S. EPA noted in the November 2022 Revised Risk Determination there was no evidence for a belief of widespread noncompliance with PPE and Occupational Safety and Health (OSHA) standards. There was no evidence to support this reversal and it violated TSCA’s rules that PPE must be taken into account.
Third, the Fifth Circuit Court analyzed U.S. EPA’s approach to unreasonable risk both legally and methodologically. U.S. EPA’s mandate is to identify only unreasonable risks and to only regulate to eliminate unreasonable risks based on individual conditions of use. During the risk assessments, U.S. EPA’s approach was to remove all risks. The court agreed that U.S. EPA’s legal approach was substantially more conservative than unreasonable risk indicates and that TSCA was not created as a zero-risk rule. In addition, the court determined the methodology used to determine the exposure limits for acute and chronic exposure lacked epidemiological support and was not completed according to TSCA’s requirement to use the best available science to conduct the risk analysis. Finally, the court denied the Sierra Club’s petition for review on a basis of lack of merit.
What does this mean?
The vacatur mandate has not been officially issued by the court. Once that is completed, all prohibitions, restrictions, workplace requirements, and exposure limits created by the Methylene Chloride Rule are no longer in effect and do not need to be followed. However, established OSHA exposure limits and other environmental limits for MC still apply to industries and organizations using the chemical. If your site has invested in a WCPP there may be valuable portions of the program to retain. This decision only applies to MC and its risk determination and analysis; this does not vacate risk analyses for other chemicals identified for risk evaluation and risk management and any established rules. U.S. EPA has not responded to the ruling or indicated how it will proceed following the ruling.
ALL4’s safety and chemicals team members can assist with evaluating and improving chemical safety programs. For more information about MC requirements and other TSCA controlled chemicals, reach out to your ALL4 project manager, Scott Kirkpatrick at skirkpatrick@all4inc.com , or Staci McGill at smcgill@all4inc.com.
