The United States Environmental Protection Agency (EPA) has conducted a health and environmental risk assessment of Diisononyl Phthalate (DINP) under Section 6 of the Toxic Substances Control Act (TSCA). The assessment indicates that under current usage conditions, DINP poses an unreasonable risk to human health.
The EPA evaluated 47 Conditions of Use (COUs) for DINP, identifying concerns about worker exposure in four specific use scenarios, including the industrial and commercial use of adhesives and sealants, as well as industrial and commercial applications of paints and coatings. These four scenarios account for approximately 3% of DINP's production volume in the US.
DINP is primarily used as a plasticizer in the production of flexible Polyvinyl Chloride (PVC). It is also used in the manufacture of building and construction materials, automotive products, and other commercial and consumer products such as adhesives and sealants, paints and coatings, and electrical and electronic goods. According to the latest 2020 Chemical Data Reporting rule, DINP production ranged from 100 to 250 million pounds in 2015, decreasing to 50 to 100 million pounds by 2019.
The EPA also reviewed studies investigating the potential of DINP to cause cancer, concluding that DINP can induce liver cancer in experimental animals at doses higher than those observed for other non-cancer liver effects. Therefore, assessing and protecting human health from the non-cancer risks of DINP will also help prevent cancer effects.
Following public comments and peer review, the EPA will issue the final cumulative risk assessment for DINP and will initiate regulatory measures to mitigate these risks.
