On November 27, 2020, the U.S. Environmental Protection Agency (EPA) announced the availability of the draft scope documents for the manufacturer-requested risk evaluations of diisodecyl phthalate (DIDP) and diisononyl phthalate (DINP). 85 Fed. Reg. 76077; 85 Fed. Reg. 76072. EPA notes in its November 25, 2020, announcement that both DIDP and DINP “belong to a family of chemicals called phthalates and are commonly used as plasticizers in the production of plastic and plastic coating to increase flexibility.” EPA seeks public input on the draft scope documents, which include the conditions of use to be included in the risk evaluations, the next step in the process. Comments on the draft scope documents are due January 11, 2021. EPA will use public comments to inform the final scope documents.

EPA states that it generally conducts manufacturer-requested risk evaluations in the same manner as other risk evaluations conducted under the Toxic Substances Control Act (TSCA). The draft scope documents issued include conditions of use, hazards, exposures, and the potentially exposed or susceptible subpopulations that EPA will consider in the risk evaluations. The documents also include a description of the reasonably available information and the best available science approaches that EPA will use; a conceptual model that outlines the potential hazards and exposures throughout the life cycle of the chemical; an analysis plan to identify the approaches and methods EPA will use to assess health and environmental risks; and a plan for peer review. More information on the manufacturer requests for risk evaluations of DIDP and DINP is available in our August 19, 2019, memorandum, “EPA Begins Comment Period on Manufacturer Requests for Risk Evaluation of DIDP and DINP, and Identifies Additional Conditions of Use.”

DIDP

According to the draft scope of the risk evaluation for DIDP, EPA plans to evaluate manufacturing (including importing); processing; distribution in commerce; industrial, commercial, and consumer uses; and disposal of DIDP in the risk evaluation. DIDP is manufactured (including imported) in the United States. The chemical is processed as a reactant; incorporated into a formulation, mixture, or reaction product; and incorporated into articles. The draft scope states that the identified processing activities also include the repackaging and recycling of DIDP. According to EPA, DIDP is primarily used as a plasticizer in polyvinyl chloride (PVC) in consumer, commercial, and industrial applications. The industrial and commercial uses identified include automotive, fuel, agriculture, and outdoor use products. Consumer uses such as furnishing, cleaning, and treatment/care products were also identified.

The draft notes that 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 for which production may have ceased. EPA presented the proposed additions of these EPA-identified conditions of use and the basis for these proposed additions, along with the manufacturer request, for a 45-day comment period in August 2019.

DINP

According to the draft scope of the risk evaluation for DINP, EPA plans to evaluate manufacturing (including importing); processing; distribution in commerce; industrial, commercial, and consumer uses; and disposal of DINP. DINP is manufactured (including imported) in the United States. EPA states that DINP is processed as a reactant; incorporated into a formulation, mixture, or reaction product; and incorporated into articles. The identified processing activities also include the repackaging and recycling of DINP. DINP is primarily used as a plasticizer in PVC in consumer, commercial, and industrial applications. EPA identified industrial and commercial uses including automotive, fuel, agriculture, and outdoor use products and construction, paint, electrical, and metal products. Identified consumer uses include furnishing, cleaning, and treatment/care products.

EPA notes that 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 CDR, published literature, and consultation with stakeholders for both uses currently in production and uses for which production may have ceased. EPA presented the proposed additions of these EPA-identified conditions of use and the basis for these proposed additions, along with the manufacturer request, for a 45-day comment period in August 2019.

Commentary

The draft scoping documents provide a first look into EPA’s approach to evaluating these two phthalates. Not surprisingly, there is significant overlap between the properties and conditions of use of the two chemical substances. Although EPA does not specifically refer to legacy uses, EPA appears to be considering releases and exposures due to disposal and recycling of articles that contain DIDP and DINP without specifying whether such articles are already in use or may be sent for waste management in the future.

EPA specifically excludes the use of both DIDP and DINP as components in food packaging from the risk evaluation because chemicals used as food additives (including as indirect food additives, such as a component of packaging) are, by definition in TSCA Section 3(2)(B)(vi), not chemical substances for TSCA purposes. EPA also excludes the use of DIDP as a component of munitions by the exclusion of such components in TSCA Section 3(2)(B)(v).

EPA identified hundreds of data sources in its search of the grey literature (sources other than peer-reviewed journals, including dissertations, conference presentations, white papers, and other such publications). B&C expects that EPA will evaluate these sources in addition to the information provided by the requesting parties and other information from open literature and information known to EPA using its data quality standards. Presumably, all such information will be considered and incorporated in the risk evaluation, as appropriate.