On August 31, 2021, EPA released Toxic Substance Control Act (TSCA) final scope documents for diisodecyl phthalate (DIDP) and diisononyl phthalate (DINP). The final scope documents are the first to implement the Agency’s new policy for considering exposure to the chemicals from media that are regulated outside of TSCA including air and water, including drinking water. In a press release on the path forward for risk evaluations, the Agency noted that the previous administration’s “…approach to exclude certain exposure pathways also resulted in a failure to consistently and comprehensively address potential exposures to potentially exposed or susceptible subpopulations, including fence-line communities (i.e., communities near industrial facilities).” Both risk evaluations were requested by the manufacturer, ExxonMobil, through the American Chemistry Council’s High Phthalates Panel (ACC HPP).
The scope documents for these risk evaluations includes the following information: the conditions of use, potentially exposed or susceptible subpopulations (PESS), hazards, and exposures that EPA plans to consider, along with a description of the reasonably available information and science approaches EPA plans to use in the risk evaluations, a conceptual model, an analysis plan, and the plan for peer review of the draft risk evaluation for this category of chemical substances.
Some of these conditions of use were identified in the manufacturer request as circumstances on which EPA was requested to conduct a risk evaluation. EPA identified other conditions of use from information reported to EPA through Chemical Data Reporting (CDR), published literature, and consultation with stakeholders for both uses currently in production and uses whose production may have ceased
EPA plans to evaluate releases to the environment as well as human and environmental exposures resulting from the conditions of use of these substances that EPA plans to consider in the risk evaluation. In addition to including occupational exposure, consumer and bystander exposure, and PESS, the scope of the risk evaluations will include general population exposures. Specifically, EPA plans to evaluate general population exposure to the substances via the oral route from drinking water, surface water, groundwater, ambient air, soil, fish ingestion, and human breast milk; via the inhalation route from air and drinking water; and via the dermal route from contact with drinking water, surface water, groundwater and soil.
In addition to considering the data and information sources provided by the ACC HPP submissions, EPA conducted a comprehensive search to identify and screen multiple evidence streams (i.e., chemistry, fate, release and engineering, exposure, hazard) to inform the development of these scoping documents.