1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-Hexamethylcyclopenta [g]-2-Benzopyran (HHCB) and Phthalic Anhydride Draft Risk Evaluations Under the Toxic Substances Control Act (TSCA); Notice of Availability and Request for Comment

Polynt Composites USA Inc. is submitting a revised Safety Data Sheet (SDS) for phthalic anhydride to the EPA. They are requesting that the Agency use this updated SDS, which corrects an error regarding reporting thresholds, in its risk evaluation of the substance.

The American Coatings Association (ACA) opposes the EPA's draft risk evaluation of phthalic anhydride, arguing that the EPA overestimates exposure levels in end-use products by conflating resin manufacturing with downstream paint formulation. The association contends that phthalic anhydride is largely consumed during the resin-making process, leaving only trace amounts in final products, and requests that the EPA use updated Safety Data Sheets (SDS) and more representative scientific studies.

A group of scientists, academics, and clinicians, including representatives from Stanford University, argue that the EPA's Draft Risk Evaluation for Phthalic Anhydride is scientifically flawed and fails to protect human health. They contend that the EPA used inappropriate statistical models, underestimated risks to susceptible subpopulations, and relied on industry-influenced methodologies that downplay non-cancer hazards.

The Environmental Defense Fund (EDF) argues that the EPA's Draft Risk Evaluation for Phthalic Anhydride significantly underestimates risks to workers, consumers, and fenceline communities. They specifically criticize the EPA's assumptions regarding hydrolysis rates in air, the failure to account for synergistic mixture effects between phthalic anhydride and o-phthalic acid, and the use of insufficiently protective uncertainty factors.

The American Chemistry Council (ACC) Phthalic Anhydride TSCA Risk Evaluation Consortium submitted comments supporting the EPA's draft risk evaluation of phthalic anhydride. They argue that the substance does not present an unreasonable risk to the environment and advocate for specific technical refinements regarding hazard assessments, uncertainty factors, and occupational exposure characterization.

Integral Consulting Inc., representing Stepan Company, argues that the EPA's draft risk evaluation for phthalic anhydride is overly conservative and based on inaccurate exposure data. They advocate for prioritizing more recent, well-annotated data, revising the dermal sensitization benchmark, and reducing the proposed uncertainty factors to better reflect actual occupational conditions.

The American Chemistry Council (ACC) supports the EPA's determination that HHCB does not present an unreasonable risk to human health or the environment. They also provide technical feedback on risk assessment methodologies, advocating for clearer problem formulation, tiered risk assessment, and the use of specific New Approach Methodologies (NAMs) to reduce animal testing.

The People’s Republic of China submitted comments regarding the draft risk evaluations for HHCB and Phthalic Anhydride. The government requests that the EPA recognize equivalent overseas safety measures, clarify specific high-risk conditions of use to avoid broad trade restrictions, and provide precise definitions for "spray-type" consumer products.

The Alliance for Automotive Innovation supports the EPA's draft risk evaluation but requests the inclusion of a 0.1% de minimis threshold for chemical reporting to align with industry standards and other federal rules. They also urge the EPA to expressly exclude replacement parts for complex durable goods from future risk management requirements to ensure the continued availability of essential vehicle components.

The Aerospace Industries Association (AIA) provides feedback on the EPA's draft risk evaluation for phthalic anhydride, emphasizing its critical role in aerospace and defense manufacturing. They request clarification on specific conditions of use (COUs) to ensure accurate classification and propose a performance-based approach for personal protective equipment (PPE) rather than prescribing specific glove models.