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The U.S. Environmental Protection Agency (EPA) announced on June 6, 2022, that it issued the first in a series of Toxic Substances Control Act (TSCA) test orders to require companies to conduct and submit testing on per- and polyfluoroalkyl substances (PFAS). EPA issued the order as part of its PFAS Strategic Roadmap. When EPA announced the Strategic Roadmap to confront PFAS contamination nationwide, it also released the National PFAS Testing Strategy to help identify PFAS data needs and require testing to fill those gaps. More information on EPA’s PFAS Strategic Roadmap and National PFAS Testing Strategy is available in our October 19, 2021, memorandum.
Test Order
EPA selected 6:2 fluorotelomer sulfonamide betaine (Chemical Abstracts Service Registry Number (CAS RN) 34455-29-3) as the first test order issued pursuant to the National PFAS Testing Strategy. According to EPA, 6:2 fluorotelomer sulfonamide betaine has been manufactured (defined to include importing) in significant quantities (more than 25,000 pounds in a given year) according to TSCA Chemical Data Reporting (CDR) rule reports. EPA states that it is a surfactant used to make commercial fire-fighting foams and may be found in certain floor finishes. CDR data also indicate that at least 500 workers in a given year could be potentially exposed to this chemical. Although there is some hazard and exposure information available, EPA states that it found there are insufficient data to determine the effects on human health associated with the inhalation route of exposure. EPA intends the test order to address this data need.
The Chemours Company, E.I. duPont De Nemours and Co., National Foam Inc., and Johnson Controls Inc. are the recipients of the test order. According to EPA, the companies subject to the test order may conduct the tests as described in the order, including testing of physical-chemical properties and health effects following inhalation, or provide EPA with existing information that they believe EPA did not identify in its search for existing information. EPA states that it “encourages companies to jointly conduct testing to avoid unnecessary duplication of tests.” The test order employs a tiered testing process, as required by TSCA. The results of all the first-tier testing are required to be submitted to EPA within 400 days of the effective date of the order and will inform the decision as to whether additional tests are necessary. Any data submitted in response to the order that are not subject to a valid confidentiality claim will be made publicly available on EPA’s website and in Docket EPA-HQ-OPPT-2021-0897.
EPA states that developing TSCA Section 4 test orders “is a complex and resource-intensive process involving many scientific and regulatory considerations,” as explained in EPA’s Overview of Activities Involved in Issuing a TSCA Section 4 Order. EPA notes that with this test order, it is “for the first time describing the process future PFAS test orders will follow to obtain data on human health effects pursuant to a ‘may present an unreasonable risk’ finding” under TSCA Section 4(a)(1). The testing will “comprehensively yet efficiently” investigate human health endpoints, applying testing methodologies appropriate for the physical-chemical properties of the subject PFAS. EPA notes that given the complexity of the testing requirements, a “broad spectrum of experts” across many EPA offices worked to determine testing methodology and needs and address other details that go into the process of drafting and issuing an order, including assessing the economic burden of an order.
EPA states that one order often applies to multiple companies. EPA must identify these companies and their associated points of contacts. To improve the transparency of the process, EPA tries to resolve confidential business information (CBI) claims that could prevent it from publicly connecting the company to the chemical substance prior to issuing test orders.
National PFAS Testing Strategy
In the National PFAS Testing Strategy, EPA assigned 6,504 PFAS into smaller categories based on similarities in structure, physical-chemical properties, and existing toxicity data. According to EPA, it identified 24 categories that lack toxicity data to inform EPA’s understanding of the potential human health effects and contain PFAS with at least one identifiable manufacturer to whom EPA could issue a test order. As EPA continues to develop the National PFAS Testing Strategy further, and following the review of some stakeholder feedback, EPA states that it also plans to increase the weight it places on the potential for exposures when identifying the representative PFAS for each category.
Based on EPA’s experience to date in developing tiered testing strategies for PFAS, EPA states that it will also be important to have a better, upfront understanding of physical-chemical properties for the wide variety of PFAS included in the National PFAS Testing Strategy. According to EPA, the information from these initial orders will provide EPA with critical information on more than 2,000 similar PFAS that fall within these categories. This information will allow EPA to make better-informed decisions about PFAS, as well as guide any future orders. EPA states that it plans to issue additional Phase I orders “in the coming months.” EPA notes that based on available information and predictive models, testing on 6:2 fluorotelomer sulfonamide betaine will also inform its understanding of the human health effects of 503 additional PFAS with similar structures as detailed in the Testing Strategy.
Commentary
The issuance of the test order was expected. This TSCA test order is significant because it is the first of an expected broad series of test orders for substances representative of categories of PFAS for which there are limited, existing toxicity data and for which there is at least one identifiable manufacturer or processor of a category member. Bergeson & Campbell, P.C. (B&C®) notes that EPA used its authority for issuing the test order under TSCA Section 4(a)(1). We mention this because of the misleading title of the test order (i.e., “Order Under Section 4(a)(2) of the Toxic Substances Control Act”) and it is the first test order issued under TSCA Section 4(a)(1). Below, we have provided representative examples in the test order that raise questions as to whether EPA met its statutory obligations under TSCA Section 26 with using the best available science, weight of scientific evidence, and reasonably available information.
B&C notes that the test order is conspicuously lacking any mention of the systematic review method that EPA used for determining its data needs. The order discusses the elaborate process that EPA used for categorizing PFAS and identifying existing information. This process, however, seems to have overlooked existing information on physicochemical properties as EPA instead used modeling to estimate, or required to produce as part of the ordered testing. For example, EPA estimated the following physicochemical properties using the Open (Quantitative) Structure-activity/property Relationship App (OPERA v2.8.2):
- Vapor pressure (0.000025 mmHg);
- Water solubility (1.16 mg/L);
- Melting point (77 °C); and
- Boiling point (246 °C).
Based on these estimates, EPA concluded that “6:2 fluorotelomer sulfonamide betaine…is expected to be an insoluble solid substance and therefore may present concern for portal-of-entry effects for inhalation exposures.”
In comparison, B&C looked up the CAS RN (i.e., 34455-29-3) for 6:2 fluorotelomer sulfonamide betaine on the European Chemicals Agency (ECHA) Registered Substances Database and identified publicly available entries for the following measured physicochemical properties (i.e., the same properties EPA estimated):
- Vapor pressure (0.017 Pa at 25 °C);
- Water solubility (ca. 50 mg/L at 20 °C, pH 4.4 – 7.7, “slightly soluble”);
- Melting point (“Test substance partially melted before decomposing at temperatures above approximately 150°C”); and
- Boiling point (waived because the test substance “Decomposed before a boiling point could be reached”).
EPA also ordered testing on 6:2 fluorotelomer sulfonamide betaine, despite the availability of existing measured data. For example, EPA ordered “Particle Density” testing according to the Organization for Economic Cooperation and Development’s (OECD) test guideline 109 and “Hydrolysis as a Function of pH” testing according to OECD test guideline 111. B&C notes that the ECHA registrant performed testing on 6:2 fluorotelomer sulfonamide betaine according to OECD test guidelines 109 and 111.
The existence of these data would seem to suggest deficiencies with EPA’s process for evaluating PFAS in general because the ECHA Registered Substances Database was included in EPA’s search. Further, EPA’s conclusion that 6:2 fluorotelomer sulfonamide betaine is insoluble, based on an estimated value versus being “slightly soluble” based on measured data, will likely be a source of contention between EPA and the test order recipients. EPA did not state whether it used a systematic review method to inform its conclusions to order specific testing. EPA stated, however, that “…for human health animal toxicity studies all submitted existing information will be evaluated for study quality using the TSCA systematic review method (EPA-HQ-OPPT-2021-0414-0005, Appendix Q.4.2).” B&C notes that the referenced method is still in draft. Moreover, B&C questions EPA’s decision to develop the test order on 6:2-fluorotelomer sulfonamide betaine without using a systematic review method, since doing so would have avoided the omissions mentioned above and would have aligned better with the scientific standard requirements under TSCA Section 26.
EPA stated its concern for portal-of-entry effects in the respiratory tract for 6:2-fluorotelomer sulfonamide betaine because, according to EPA, it is an insoluble particle. EPA also stated the following under the header for “Hazard and Exposure for PFAS”:
Some PFAS can cause adverse effects on the respiratory system following acute inhalation exposures (e.g., Per- and polyfluoroalkyl substances (PFASs) modify lung surfactant function and pro-inflammatory responses in human bronchial epithelial cells (Sørli et al., 2020) and Anionic Surfactants Category in TSCA New Chemicals Program (NCP) Chemical Categories (USEPA/OPPT, 2010)[)].
B&C agrees with EPA’s citation to Sørli et al. (2020) with regard to acute inhalation hazards. We are perplexed, however. by EPA’s citation to the Anionic Surfactants Category from the “TSCA New Chemicals Program (NCP) Chemical Categories,” which only addresses environmental toxicity.
As part of its justification for in vivo inhalation toxicity testing, EPA stated that it “…considered in vitro respiratory toxicity models and found that currently available in vitro respiratory tract cell culture models are only relevant to water-soluble and gaseous substances.” B&C notes that this statement seems to conflict with presentations given by EPA scientists at the Society of Toxicology meeting in March 2021 that recommended in vitro test systems for poorly soluble particles and aerosolized surfactants. Further, non-EPA scientists have published on the utility of in vitro respiratory tract cell culture models for testing water-insoluble gas/vapor phase fractions of substances, as well as nanomaterials and/or insoluble materials.
B&C applauds EPA’s efforts to obtain additional data on PFAS chemicals to enhance its understanding of these chemistries. B&C questions, however, EPA’s apparent rush to issue this test order, rather than giving thoughtful consideration of the existing data and how EPA would use ordered testing to fill data needs and meet its obligations under TSCA Section 4. B&C suspects that the test order recipients may raise these and other issues, and possibly legal challenges. Whether it goes the way of the test order on which the Vinyl Institute recently filed suit remains to be seen.