EPA Publishes Draft Risk Evaluation for DINP

The United States Environmental Protection Agency (US EPA) published its Draft Risk Evaluation for Diisononyl Phthalate (DINP) in August 2024, in accordance with the Toxic Substances Control Act (TSCA), as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act. DINP, a category of phthalates, is mainly used as a plasticizer in polyvinyl chloride (PVC) and other polymer products (EPA 2024). EPA preliminarily found that DINP poses an unreasonable risk of developmental toxicity and liver damage in two industrial uses and one consumer use, and may cause cancer at higher exposure levels.

 The draft risk evaluation for DINP is one of a few published since the updated Procedures for Chemical Risk Evaluation Under the Toxic Substances Control Act (TSCA) rule was published in May 2024.  Additionally, the draft risk evaluation is framed by the Draft Proposed Approach for Cumulative Risk Assessment of High-Priority Phthalates and a Manufacturer-Requested Phthalate under the Toxic Substances Control Act, in which the shared toxicological properties of the seven phthalates under risk evaluation--DEHP, BBP, DBP, DIBP, DCHP, DINP, DIDP--are assessed and applied to the individual phthalate risk evaluations. Looking forward, EPA plans to develop methods and approaches for conducting cumulative risk evaluations (CRAs), complete the phthalate CRA using individual phthalate risk evaluations, and finalize the individual phthalate risk evaluations with the results of the CRA.