On October 14, 2020, a coalition of non-governmental organizations (NGO) petitioned the U.S. Environmental Protection Agency (EPA) under Section 21 of the Toxic Substances Control Act (TSCA) to request that EPA require health and environmental effects testing on 54 per- and polyfluoroalkyl substances (PFAS). The petition seeks issuance of a rule or order under TSCA Section 4 compelling The Chemours Company (Chemours) to fund and carry out this testing under the direction of a panel of independent scientists. EPA acknowledged receipt of the petition, noting that TSCA Section 21 provides that the EPA Administrator shall either grant or deny a petition within 90 days (January 11, 2021, in this case) after the date of filing. If the Administrator grants the petition, the Administrator shall promptly commence an appropriate proceeding. If the Administrator denies the petition, the Administrator shall publish the reasons for such a denial in the Federal Register. EPA states that the petition is under review by the Office of Pollution Prevention and Toxics (OPPT). The petition was filed by the following non-profit public health, environmental, and environmental justice groups based in North Carolina -- Center for Environmental Health, Cape Fear River Watch, Clean Cape Fear, Democracy Green, the NC Black Alliance, and Toxic Free NC.

According to the petition, the Fayetteville chemical manufacturing facility, located on the Cape Fear River upstream of Wilmington, North Carolina, “has long been a major producer and user of PFAS under the ownership of E. I. DuPont de Nemours & Company, Inc. (DuPont) and, since 2015, Chemours, a DuPont spinoff.” The petition states that several of these PFAS have been identified in drinking water sources serving over a quarter of a million people in the Cape Fear watershed, in human blood, and in environmental media. Petitioners have identified a total of 54 PFAS (not including legacy substances) that they claim are attributable to the Chemours facility and have been detected in environmental media and/or people in the Cape Fear River watershed.

The petition acknowledges that under a consent order between EPA and Chemours, GenX compounds have undergone some toxicological testing but states that available studies are incomplete. According to the petition, there is also some testing underway on a small number of other PFAS under a North Carolina consent order, but these studies are limited in scope. The petition states that no health or environmental effects testing has been conducted on the remainder of the 54 PFAS, and for all 54 substances, there are insufficient data to determine risks to the exposed population and the surrounding ecosystem and to set risk reduction targets and other protective measures.

The petition states that “[l]eading authorities have recognized that, because of the similarities in persistence, mobility, and toxicity among PFAS, all members of the class have the potential to cause the same adverse effects as well-characterized compounds such as PFOA [perfluorooctanoic acid] and perfluorooctane sulfonate (PFOS).” The petition argues that based on the known hazards of these analogues, untested PFAS with potential for exposure would meet the criteria for testing in TSCA Section 4(a)(1)(A) “because they (1) ‘may present an unreasonable risk of injury’ and (2) have ‘insufficient information and experience’ to determine their effects on health or the environment.” According to the petition, “EPA took this very approach in reviewing GenX compounds under the related ‘new chemicals’ provisions in section 5 of TSCA: it issued a consent order requiring testing based on findings that these compounds ‘may present an unreasonable risk’ because of their similarities to PFOS and PFOA and ‘the information available to the Agency is insufficient to permit a reasoned evaluation of the[ir] human health and environmental effects.’”

The petition states that the same conclusions are required under TSCA Section 4(a)(1)(A) for the 54 specified PFAS based on their similarities to other well-studied PFAS, evidence of actual or likely human exposure and lack of sufficient data for informed determinations of risk. According to the petition, testing is “necessary” under TSCA Section 4(a)(1)(A) of TSCA because there is no other scientifically sound and reliable method for determining their health and environmental effects. The petition thus asks EPA to issue a test rule or order requiring Chemours “to fund studies necessary to understand the likely health and environmental risks from past and ongoing exposure to the 54 PFAS.”

According to the petition, some of the 54 PFAS proposed for testing are intended commercial products, while others are byproducts created during the manufacture of commercial products. The petition states that the testing authority in TSCA Section 4 applies to both commercial products and byproducts from a commercial chemical manufacturing process. Thus, both types of PFAS are subject to Section 4 testing requirements.

According to the petition, Chemours is taking steps to control environmental releases of PFAS under a February 2019 consent order issued by the state of North Carolina. The petition states that these measures “are critical to reduce human exposure to the 54 PFAS and should not be delayed while the testing proposed by this petition is underway.” At the same time, the petition argues that “it is important to recognize that Chemours’ actions to reduce exposure do not eliminate the need for testing because PFAS exposure is continuing despite these actions and understanding the health impacts of both ongoing and historical exposure remains essential to protect exposed communities in the Cape Fear Watershed.”

This petition asks that EPA require under Section 4 a broad array of testing on the 54 PFAS chemicals and certain mixtures of PFAS chemicals. It proposes that the scope of testing would differ, depending on whether compounds fall into “Tier 1” (i.e., chemicals where there has been detection in human sera, food, or drinking water) or “Tier 2” (i.e., chemicals where there is significant potential for human exposure based on detection in environmental media and other evidence). The petition proposes the following testing program:

Experimental Animal Studies

• Compounds in both Tiers would undergo 28-day repeated dose rodent toxicology studies coupled with reproductive and developmental toxicity screening assays, examining critical PFAS endpoints, including hormone disruption, liver and kidney damage, developmental and reproductive harm, changes in serum lipid levels, and immune system toxicity.

• These studies also would be conducted on three mixtures of PFAS representative of the groups of substances to which residents have been exposed through drinking water, human sera, and other pathways.

• Multi-generation or extended one-generation and two-year rodent carcinogenicity studies would be conducted on the 14 Tier 1 substances in recognition of the evidence of direct and substantial human exposure and the concerns for these endpoints demonstrated by other PFAS.

• Most studies would be carried out in two species (mice and rats) and by oral routes of administration, except inhalation would be used for volatile chemicals.

• Toxicokinetic studies would be conducted to characterize relationships between serum concentrations and dermal, oral, and inhalation exposures in the test species, and to evaluate biological half-life and potential for bioaccumulation.

• Testing requirements would be based on EPA and Organization for Economic Cooperation and Development (OECD) guidelines, with appropriate adjustments to reflect sensitive endpoints that have been reported for PFOA, PFOS, and GenX.

Human Studies

• A human health study for the Cape Fear watershed would be conducted using a similar study design to that used for the Parkersburg, West Virginia, PFOA (C8) study. The goal of the study would be to determine the relationship between exposure to the mixtures of PFAS that characterize current and historical exposure in the Cape Fear watershed and health outcomes among exposed populations.

• Testing also would be performed to determine human half-lives of the listed chemicals through longitudinal biomonitoring and exposure estimation in workers.

Ecological Effects/Fate and Transport and Physical-Chemical Properties Studies

• Testing would include ecological effects studies, similar to studies conducted on GenX.

• EPA would require development of analytical standards where not currently available, physical-chemical properties tests, and fate and transport studies to identify and predict exposures.

Avoidance of Duplication

• Chemours would not be required to repeat studies already conducted or in progress on GenX and the five substances subject to a North Carolina consent order but, according to the petition, because these studies are insufficient, additional studies on these PFAS would be conducted.

Independent Science Panel

• The petition requests that “[t]o maximize the credibility and objectivity of the data and key findings, EPA would contract with the National Academy of Sciences (NAS) to form an independent expert science panel with responsibility for overseeing all aspects of the testing program. The public and Chemours would have the opportunity to submit nominations for membership on the panel.”

Commentary

We see merit in some aspects of the petition, although it is not clear that the petition meets the statutory and regulatory requirements for EPA to grant the petition. In addition, it is unlikely that all the requested testing is needed or justified on each of the 54 chemicals and three mixtures. It may be feasible and technically appropriate, for example, for EPA to identify a subset of the PFAS chemicals for testing that is representative of other PFAS chemicals; this would reduce testing costs and help EPA meet the TSCA Section 4(h) requirement to reduce testing on vertebrates.

The petition also does not acknowledge the requirement that EPA take a tiered approach -- in the traditional toxicological meaning of testing tiers in which lower tier testing is performed to inform whether higher tier testing is justified. Tiered testing is a standard practice and avoids duplicative testing, keeps testing costs down, and greatly reduces the number of animals tested. The petitioners divide the substances into two tiers -- one tier that would be subjected to the full suite of toxicity testing and a second tier that would be subjected to that same testing in addition to medical monitoring. The petition acknowledges that Chemours would not be required to repeat studies. Finally, the petitioners were either not aware of or did not acknowledge that some of the requested testing has already been completed for Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) registrations in support of some of the substances. This suggests that perhaps the petitioners are not actually seeking to fill data gaps as noted, but rather are aiming at imposing aggressive testing requirements on Chemours.

Additionally, we question whether a requirement that EPA contract with NAS to form an independent science review panel with responsibility for overseeing all aspects of the testing program is petitionable under TSCA Section 21 or justified. Contract testing by labs performing under the Good Laboratory Practice (GLP) standards is accepted around the world.

EPA has, since the passage of Lautenberg, used its TSCA Section 4 testing authority very sparingly, including only a test order on Pigment Violet 29 to inform the TSCA Section 6 risk evaluation of the substance. Although we believe this will likely change as EPA continues to prioritize chemicals for risk evaluation and in evaluating the risk of substances identified as “high priority” for risk evaluation, especially where chemicals become increasingly “data poor,” a grant or partial grant of the petition may signal an increased interest by EPA in using its testing authority to require the development of information to inform its assessment of chemicals under TSCA or other authorities.