/>iOn October 9, 2024, the U.S. Environmental Protection Agency (EPA) announced that it has issued its fifth Toxic Substances Control Act (TSCA) test order requiring testing on per- and polyfluoroalkyl substances (PFAS) under its National PFAS Testing Strategy. The order requires Innovative Chemical Technologies, The Chemours Company, Daikin America, Inc., Sumitomo Corporation of Americas, and E.I. Du Pont de Nemours and Company to conduct and submit testing on 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl prop-2-enoate, also known as 6:2 fluorotelomer acrylate (6:2 FTAc). According to EPA, 6:2 FTAc is used to manufacture plastics, resins, textiles, apparel, leather, and other chemicals. EPA states that “[b]etween one million and 20 million pounds are produced per year.”
According to EPA, summaries of studies of rodents exposed to 6:2 FTAc “suggest it causes changes in blood cell counts, liver and kidney size, and animal behavior. Further, the chemical structure of 6:2 FTAc suggests that it may cause cancer.” EPA states that it “finds that 6:2 FTAc may present an unreasonable risk of injury to health or the environment, given the hazard and exposure concerns for this chemical specifically and for PFAS generally.” EPA notes that information received under the order, especially toxicity information, will improve its understanding “not only of human health effects of 6:2 FTAc, but also of the potential effects of over a hundred PFAS that are structurally similar to 6:2 FTAc. The information will also add to EPA’s overall knowledge of this category of PFAS.”
The companies subject to the test order may either conduct the tests as described in the order, including testing of physical-chemical properties and health effects following exposure, or provide EPA with existing information they believe EPA did not identify in its search, but that satisfies the order requirements. EPA encourages companies to conduct testing jointly to avoid unnecessary duplication of tests and states that it will also consider possible combinations of tests that cover several required endpoints to reduce time, costs, and the use of animal subjects.
The order employs a tiered testing process, as required by TSCA. EPA issued the order on October 8, 2024, and it was effective October 13, 2024. The results of all but one of the first-tier tests are required to be submitted to EPA within one year of the effective date of the order. EPA notes that hydrolysis as a function of pH is a first-tier test and its completion is required within 390 days of the effective date of the order. According to EPA, the results of the first-tier tests will inform its decision as to which additional tests are necessary or how they may need to be conducted. EPA will make the order and any data submitted in response to the order publicly available on its website and in Docket Number EPA-HQ-OPPT-2024-0364 at https://www.regulations.gov, subject to confidentiality considerations under TSCA Section 14.
Commentary
EPA is expected to initiate ten test orders per year on PFAS based on EPA’s National PFAS Testing Strategy. The projected total annual costs are $1,571,000. Bergeson & Campbell, P.C. (B&C®) is a bit surprised that EPA issued a test order on 6:2 FTAc. This substance has a robust existing data set that is summarized publicly on the European Chemicals Agency’s (ECHA) registered substances database. EPA also includes links to these summaries as part of its CompTox Chemicals Dashboard. It is somewhat puzzling why EPA would devote its limited resources issuing this test order. After all, EPA’s National PFAS Testing Strategy is focused on identifying PFAS that lack toxicity data and have an identifiable manufacturer to whom EPA could issue a test order. EPA can identify targets for the order, but it is not clear there is a significant lack of toxicity data.
EPA summarizes its authority to issue a test order under TSCA Section 4(a)(1) as follows:
EPA finds that (1) the chemical substance may present unreasonable risk or is produced in substantial quantities and may cause substantial or significant exposures to the environment or humans, (2) there is insufficient information to predict the effects of the chemical substance, and (3) testing is necessary to develop this information.
EPA stated that “[t]he biotransformation pathway of 6:2 FTAc includes hydrolysis of the ester linkage to form 6:2 fluorotelomer alcohol (FTOH), degradation of 6:2 FTOH to perfluorohexanoic acid (PFHxA) and other short-chain perfluoroalkyl carboxylic acids (PFCAs) as stable transformation products.” We mention this because EPA considers potential metabolites or degradants as part of its evaluations on new chemical substances under TSCA Section 5. Other regulatory bodies, such as Health Canada, have undertaken assessments on PFAS by considering precursors that contain the substance under evaluation. For discussion, see our memorandum dated April 22, 2024.
The publicly available robust study summaries on 6:2 FTAc on the ECHA database address nearly all of the ordered testing requirements. There is also an ECHA dossier on 6:2 FTOH, a toxicological evaluation on 6:2 FTOH published in the peer-reviewed literature (Serex et al., 2014), and EPA’s 2023 toxicological review on PFHxA and related salts on EPA’s Integrated Risk Information System (IRIS) database (IRIS, 2023). Scientists from the U.S. Food and Drug Administration (FDA) have published studies on the pharmacokinetics and biopersistence of 6:2 FTOH and its metabolites (Kabadi et al., 2018) and comparative analyses of the toxicological databases on 6:2 FTOH and PFHxA (Rice et al., 2020). Although the authors of that study concluded that “6:2 FTOH is significantly more toxic than PFHxA,” that conclusion has been contested by other scientists (Anderson et al., 2020). EPA did not opine on the comparative toxicity of 6:2 FTAc, 6:2 FTOH, or PFHxA, rather it simply stated that it “identified hazards for potential carcinogenic and toxic effects [for 6:2 FTAc]…and related concerns for health effects from its biotransformation products, including PFHxA.”
We mention the availability of this information because it is unclear how EPA made its determination that “there is insufficient information to predict the effects of the chemical substance,” if EPA did not evaluate the available information on the chemical substance and its potential metabolites/degradation products. For example, EPA does not discuss or cite any of the referenced sources on 6:2 FTOH or PFHxA in the test order and dismissed the ECHA data on 6:2 FTAc by stating that:
While the records retrieved summarized experimental findings, the underlying study reports and data were unavailable for review. Thus, the robust study summaries obtained from ECHA for review were unable to meet the data needs of this Order.
EPA also dismissed two 28-day subacute oral toxicity studies on 6:2 FTAc in rats, stating that:
The robust study summaries reported a 28-day oral exposure to 6:2 FTAc increased Sprague-Dawley rat liver and kidney size with numerous histopathological and hematological effects. Further, this 28-day study in female and male Sprague-Dawley rats, provided as a robust study summary, also reported behavioral effects, specifically reduced spontaneous locomotion in both sexes and more frequent defecation by males following administration of 6:2 FTAc. While the records retrieved summarized experimental findings, the underlying study reports and data were unavailable for review.
B&C reviewed the ECHA robust study summaries on the 28-day subacute oral toxicity studies in rats, which have report dates of 2007 and 2014. We note for comparison that EPA posted sanitized copies of full study reports on two 28-day subacute oral toxicity studies in rats with study completion dates of 2007 and 2014 on its ChemView database. These studies were submitted to EPA on December 6, 2023. EPA does not mention or cite the full study reports from ChemView in the test order, although EPA does cite other sources from 2024 (see, e.g., Ye et al., 2024). We can only speculate about why EPA might not have mentioned the 2007 and 2014 studies given that EPA stated that it queried toxicity sources on 6:2 FTAc, including EPA’s Chemical Information System (CIS), “an internal platform for managing data submissions under TSCA, including toxicity studies,” which typically houses the full studies that are posted on ChemView.
B&C mentions this as a cautionary tale for test order recipients. Recipients may be frustrated to be ordered to submit data that EPA already possesses. Recipients may also be relieved that EPA is not, for the most part, ordering new testing. It is certainly less of a burden to submit existing data than to generate new data.
