What: On January 5, 2026, the U.S. Environmental Protection Agency (EPA) published the final risk evaluation for 1,3-butadiene.
Why: 1,3-butadiene is a colorless gas essential for manufacturing products such as car tires, adhesives and sealants, paints and coatings, and automotive care products.
Under the Toxic Substances Control Act (TSCA), the purpose of a risk evaluation is to determine whether a chemical substance presents an unreasonable risk of injury to human health or the environment.
In the final risk evaluation, EPA has determined that 1,3-butadiene, under the conditions of use (COUs), presents an unreasonable risk of injury to human health driven by 11 conditions of use. These include:
- Manufacturing—domestic manufacturing.
- Manufacturing—importing.
- Processing as a reactant—intermediate (adhesive manufacturing; all other basic organic chemical manufacturing; fuel binder for solid rocket fuels; organic fiber manufacturing; petrochemical manufacturing; plastic material and resin manufacturing; propellant manufacturing; synthetic rubber manufacturing; paint and coating manufacturing).
- Processing as a reactant—monomer used in polymerization process (synthetic rubber manufacturing; plastic material and resin manufacturing).
- Processing—incorporation into formulation, mixture, or reaction product—monomers (plastic product manufacturing; plastic material and resin manufacturing; synthetic rubber manufacturing).
- Processing—incorporation into formulation, mixture, or reaction product—plasticizer (asphalt paving, roofing, and coating materials manufacturing).
- Processing—incorporation into article—monomer (rubber product manufacturing).
- Processing—use-non-incorporative activities—fuel (petroleum refineries).
- Processing—repackaging—(wholesale and retail trade fuel; synthetic rubber manufacturing; petrochemical manufacturing).
- Processing—recycling.
- Disposal.
Action: The EPA will now move forward with a TSCA risk management rulemaking for 1,3-butadiene. This rulemaking will consider:
- The effects of 1,3-butadiene on health and the environment.
- The magnitude of exposure to 1,3-butadiene of human beings and the environment.
- The benefits of 1,3-butadiene for various uses.
- The reasonably ascertainable economic consequences of the rule
If you are a small entity that uses 1,3-butadiene and think you could be impacted by EPA’s upcoming risk management rulemaking, please reach out to the Office of Advocacy.
FEDERAL REGISTER NOTICE:
1,3-Butadiene; Risk Evaluation Under the Toxic Substances Control Act (TSCA); Notice of Availability
FINAL RISK EVALUATION:
Risk Evaluation for 1,3-Butadiene
CONTACT:
Nick Goldstein
EMAIL:
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