The Environment Protection Agency (EPA) closed out 2025 with a flurry of actions involving the Toxic Substances Control Act (TSCA), including final risk evaluations for five phthalates and 1,3-butadiene, and an updated risk calculation for formaldehyde to inform a potential revised final risk evaluation in future.
Phthalates: Final Risk Evaluation and Notice of Intent to Regulate
A group of chemicals commonly used to enhance the flexibility and durability of plastics, phthalates are found in a wide array of products from building materials to consumer goods. In recently completed risk evaluations for butyl benzyl phthalate (BBP), dibutyl phthalate (DBP), dicyclohexyl phthalate (DCHP), diethylhexyl phthalate (DEHP), and diisobutyl phthalate (DIBP), the EPA identified “unreasonable” risks for workers during specific exposures (such as inhalation during spray applications and manufacturing processes) and, for four of the five chemicals, for aquatic life from surface-water releases.
The EPA did not identify unreasonable risks for consumers or for communities in close proximity to releasing facilities. The EPA’s assessment of these phthalates under TSCA does not extend to exposures from food, food additives, food packaging, medical devices, cosmetics, and other consumer products regulated by the Food and Drug Administration or the Consumer Product Safety Commission.
The EPA’s next step is to develop a rule to manage the identified risks. The timeline under the TSCA for issuing a draft rule is one year, with some allowance for extension. The EPA is considering risk mitigation measures such as personal protective equipment, engineering controls, and alternative approaches tailored to the specific uses that present risks.
1,3-Butadiene: Final Risk Evaluation and Notice of Intent to Regulate
Following a court order, the EPA issued a final risk evaluation of and notice of intent to regulate 1,3-butadiene, a colorless gas essential in the manufacture of products such as car tires, adhesives, sealants, paints, coatings, and automotive care products. The EPA concluded there is a potential unreasonable risk to workers inhaling this chemical at work in certain instances. The EPA found no unreasonable health risks to consumers using products with 1,3-butadiene, people living near facilities that use 1,3- butadiene, or the environment.
As with phthalates, it now falls to the EPA to develop risk management regulations for exposures.
Formaldehyde: Updated Draft Risk Calculation Memorandum
The EPA also issued an updated draft risk calculation memorandum for formaldehyde, a chemical widely used across numerous industries. The EPA states that this risk calculation may update the final formaldehyde risk evaluation issued in 2024, which incorporated the chronic non-cancer reference concentration and cancer inhalation unit risk developed by the Integrated Risk Information System (IRIS) program into its risk assessment for certain exposure scenarios.
Citing consistency with Executive Order 14303 (Restoring Gold Standard Science) and feedback from peer reviewers and scientific advisory committees like the Science Advisory Committee on Chemicals (SACC) and the National Academies of Sciences, Engineering, and Medicine, the EPA’s updated draft risk calculation for formaldehyde shifts away from reliance on IRIS’s chronic non-cancer reference concentration and cancer inhalation unit risk. Instead, the EPA proposes, consistent with the recommendations of SACC and other federal advisory committees, that sensory irritation be used “as the most sensitive endpoint for determining human health effects from inhalation exposures.” Managing those risks, said the EPA, will “be protective against other health effects, including cancer.” Functionally speaking, this change would raise the levels of formaldehyde that workers could be exposed to from the lower chronic non-cancer and cancer exposure levels identified by IRIS to higher levels causing sensory irritation. The revised risk calculation also results in the removal of five conditions of use that no longer indicate unreasonable risk for workers due to inhalation.
The public comment period for the December 2025 Updated Draft Risk Calculation Memorandum ends on February 2, 2026. Comments can be submitted through the official docket (EPA-HQ-OPPT-2018-0438) on regulations.gov. The EPA encourages all interested parties, including industry stakeholders, public health advocates, and members of the public, to review the memorandum and provide feedback. This input will be considered as the agency finalizes its risk evaluation and develops proposed risk management rules. Note that formaldehyde’s use as a pesticide is undergoing a separate review under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), with its own risk assessment process.
Takeaways
Recent EPA actions on phthalates, 1,3-butadiene, and formaldehyde indicate that while the EPA is advancing on high-priority chemical regulation, its approach provides potential opportunities for industries subject to those regulations.
The EPA appears to be moving away from reliance on IRIS, a program that has provoked controversy among industry for its conservative assessment of the human health toxicity of chemicals. The EPA also appears to be amenable to considering evidence indicating that a particular chemical may be considered safe below certain thresholds, while attempting to leave the door open for achievable mitigation measures by businesses at the risk mitigation stage.
Its action on formaldehyde, a chemical for which the EPA recently issued a final risk evaluation as recently as 2024, appears to carry forward the EPA’s desire (as communicated in its proposed rulemaking last year) to be able to revise final risk evaluations without having to reprioritize a chemical. This could shorten the timeframe for the EPA to review prior evaluations and issue updates consistent with current administration policy goals and updated reports from science advisory committees.
Given the multistep nature of chemical evaluations and management under TSCA, we encourage interested stakeholders to follow and consider participating in evaluation and regulatory development at all stages to ensure that points of concern are considered at each stage. Our team is ready to assist you in understanding any recent or upcoming actions under TSCA, submitting comments, or achieving compliance.
If you have any questions, or would like additional information, please contact one of the attorneys on our Environment, Land Use & Natural Resources team.
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