The U.S. Environmental Protection Agency (EPA) announced on March 7, 2025, that it is extending the comment period on the draft risk evaluation for dicyclohexyl phthalate (DCHP) under the Toxic Substances Control Act (TSCA). EPA released the risk evaluation for DCHP on January 7, 2025, with a comment period that closed March 10, 2025. EPA states that it will soon publish a Federal Register notice extending the public comment period for an additional 60 days. Upon publication of the Federal Register notice, EPA will accept public comments until May 9, 2025. 

According to EPA’s January 6, 2025, press release announcing the availability of the draft risk evaluation, DCHP is used primarily as a plasticizer or stabilizing agent in polyvinyl chloride (PVC) products and in adhesives, sealants, paints, coatings, rubbers, and other applications. EPA preliminarily determined that DCHP presents an unreasonable risk of injury to human health for workers. EPA states that nine conditions of use (COU) significantly contribute to the unreasonable risk to workers. The draft risk evaluation preliminarily shows that DCHP does not pose unreasonable risk to the environment, the general population, or consumers. EPA notes that there are other uses of DCHP that are generally excluded from TSCA’s definition of chemical substance, such as food contact materials, and EPA did not evaluate risk associated with these uses.

Workers may be exposed to DCHP when making products or otherwise using DCHP in the workplace. According to EPA, when it is manufactured or used to make products, DCHP can be released into the water where most of it will end up in the sediment at the bottom of lakes and rivers. EPA states that if released into the air, DCHP will attach to dust particles and be deposited on land or into water. Indoors, DCHP has the potential over time to come out of products and adhere to dust particles that could be inhaled or digested.