EPA Releases Draft Risk Evaluations for Two More Phthalates

EPA has released draft risk evaluations and supporting documents for diisobutyl phthalate (DIBP) and butyl benzyl phthalate (BBP) for public comment. According to the agency, DIBP, a colorless liquid, is most commonly used as a plasticizer in adhesive and sealant manufacturing. BBP, a clear, oily liquid, is also used as a plasticizer in adhesives, sealants, floor coverings, paints, and coatings, and in plastic and rubber products, EPA says.

The draft risk evaluations state that both DIBP and BBP present “unreasonable risk of injury to human health and the environment under certain conditions of use (COUs).” The Toxic Substances Control Act (TSCA) defines COU as “the circumstances . . . under which a chemical substance is intended, known, or reasonably foreseen to be manufactured, processed, distributed in commerce, used, or disposed of.” EPA’s preliminary determination of unreasonable risk to human health for these two phthalates is based on risk to workers from two COUs for DIBP and 16 COUs for BBP.

The draft risk evaluation for DIBP notes non-cancer risks from spray applications of adhesives and sealants due to acute inhalation exposure to both workers and occupational nonusers, or ONUs. Regarding BBP, EPA’s preliminary determination of unreasonable risk is based on non-cancer risks from acute, intermediate, and chronic dermal exposure to workers. BBP also presents risk for ONUs from similar exposures related to industrial and commercial uses in certain paints and coatings as well as ink, toner, and colorant products.

These draft risk evaluations do not reflect the use of personal protective equipment, which EPA says may reduce exposures and mitigate risk. They will not be peer reviewed by the Science Advisory Committee on Chemicals (SACC), a group of experts in toxicology, environmental risk assessment, exposure assessment, and related sciences that supports activities under TSCA and other statutes. SACC is reviewing draft risk evaluations for three other phthalates—dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), and dicyclohexyl phthalate (DCHP)—and EPA says that the exposure methodologies demonstrated in those evaluations will be applicable to exposure scenarios for both DIBP and BBP. According to the agency, SACC will review several technical documents that support the risk evaluations for DIBP and BBP.

Comments on the draft risk evaluations for DIBP and BBP are due by Oct. 6. To learn more, visit EPA’s risk evaluation webpages for DIBP and BBP or read the notice in the Federal Register. Individuals who wish to contribute to AIHA’s comments on the risk evaluations can share feedback through the association’s website.