The U.S. Environmental Protection Agency (EPA) has concluded its final risk evaluation under the Toxic Substances Control Act (TSCA) for diisononyl phthalate (DINP), revealing that the chemical poses an unreasonable risk to workers' health. DINP, widely used as a plasticizer in adhesives, sealants, and coatings, has been linked to developmental toxicity, liver damage, and cancer at high exposure levels.
What Is DINP and Why Is It Significant?
Diisononyl phthalate (DINP) is commonly used to improve flexibility in polyvinyl chloride (PVC) and is a component of various building materials, automotive products, and consumer items such as paints and sealants. Although DINP plays a pivotal role in product manufacturing, its health implications have raised concerns. The chemical is particularly harmful when inhaled in mist form during application processes such as spraying adhesives and coatings.
Health Risks Associated with DINP Exposure
The EPA's assessment highlights that unprotected workers in certain industries face significant health risks. The agency identified four key conditions of use contributing to these risks, including:
- Industrial Use: Adhesives, sealants, and paints in construction, electronics, and transportation sectors.
- Commercial Use: Paints and coatings in building and metal product applications.
High levels of exposure can cause developmental toxicity, liver harm, and cancer. The chemical is also linked to “phthalate syndrome,” affecting male reproductive health through decreased testosterone levels and fertility issues.
While no unreasonable risks were identified for general consumers or the environment, the EPA emphasised that workplace exposure presents a notable concern.
Environmental Impact of DINP
DINP's presence in the environment stems primarily from its manufacturing and application processes. When released into the air, it binds to dust particles and can settle on land or water. Over time, products containing DINP may release the chemical into indoor environments, increasing the likelihood of human inhalation or ingestion.
Regulatory Steps and Future Measures
The EPA has now initiated the risk management phase to mitigate DINP-related hazards. A proposed rule under TSCA Section 6 will focus on protecting workers from exposure risks. This process follows a 2019 manufacturer request for a comprehensive risk evaluation, underscoring the need for regulatory oversight.
The assessment does not extend to uses of DINP excluded from TSCA jurisdiction, such as food additives or cosmetics, where separate evaluations may apply.
