The Agency for Toxic Substances and Disease Registry issued a draft report on June 20 on perfluoroalkyl compounds, suggesting that current advisory guidelines for exposure to such contaminants may be too high. The draft report is subject to public comment, but despite the current regulatory uncertainty, businesses should begin to examine their involvement with such substances and assess potential vulnerabilities to litigation and enforcement actions.
Following mounting congressional pressure, the Agency for Toxic Substances and Disease Registry (ATSDR) (the federal public health agency arm of the US Department of Health and Human Services) last week released its highly anticipated draft toxicology study on the health effects of perfluoroalkyl compounds (PFAs), including perfluorinated substances such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). The study comes one month after the US Environmental Protection Agency (EPA) held a PFAs National Leadership Summit in Washington, DC, where EPA Administrator Scott Pruitt announced four actions EPA would take to address PFAs. The 852-page draft report, which was published in the Federal Register on June 21, suggests that stricter guidelines for human exposure to these man-made emerging contaminants of concern should be considered, dropping some recommended levels into the single-digit parts per trillion (ppt). The ATSDR’s report also suggests that human health risks may occur at levels significantly lower than the current federal recommendations. The report’s findings starkly contrast to those of the 2016 EPA health advisory for PFOA and PFOS of 70 ppt.
Perfluoroalkyl substances are a group of synthetic, non-naturally occurring chemicals predominantly used in consumer and commercial products for their fire resistant and oil, grease, and water repellency characteristics. These chemicals were typically found in wire insulation, cleaning products, pesticides and herbicides, textiles, apparel, firefighting foams, non-stick cookware, papers, paints, and carpet products. Studies have suggested that human exposure pathways to these chemicals may include ingestion of contaminated food and water and inhalation of tainted air, and that the main sources of contamination in drinking water are manufacturing facilities, airports, and military bases that historically used PFOA- and PFOS-related substances as well as facilities that used aqueous film-forming foam fire retardant. Perfluoroalkyls have been detected in all environmental media, including surface water, groundwater, air, soil, and food.
Some contend that exposure to these chemicals, even in low doses, can be harmful due to their stable and persistent characteristics, including slow degradation and ability to bio-accumulate. Yet, an axiom of toxicology is that “the dose makes the poison,” meaning that small amounts of these chemicals can be harmless. Additionally, others contend that although the now-phased-out “long-chain” perfluoroalkyls may be harmful, newer “short-chain” versions do not pose the same risks. Long-chain PFOA and PFOS are no longer manufactured or imported into the United States, and companies started phasing out the production and use of numerous perfluoroalkyls in the early 2000s; however, regulators believe that there may continue to be imported goods containing trace amounts of these substances as impurities, in addition to perfluoroalkyls substances already existing in the environment. Long-chain chemicals have been replaced by short-chain substances, which, as discussed above, some believe have less significant health effects.
The ATSDR Report and Its Findings
The ATSDR report, which “reflects ATSDR’s assessment of all relevant toxicologic testing and information that has been peer-reviewed,” provides toxicological profiles for 14 perfluoroalkyl compounds that have been previously identified in monitoring studies. The study details potential human exposure pathways and the associated potential health risks the chemicals may pose to populations ranging from infants and other vulnerable population to adult males. Each of the toxicological profiles reviews and characterizes each of the 14 compounds, as well as the adverse health effect information for each identified compound based upon a review of key literature and studies that describe each substance's toxicologic properties, including the following:
- The examination, summary, and interpretation of available toxicologic information and epidemiologic evaluations on a toxic substance to ascertain the levels of significant human exposure for the substance and the associated acute, intermediate, and chronic health effects
- A determination of whether adequate information on the health effects of each substance is available or in the process of development to determine the levels of exposure that present a significant risk to human health due to acute, intermediate, and chronic duration exposures
- Where appropriate, identification of toxicologic testing needed to identify the types or levels of exposure that may present significant risk of adverse health effects in humans
Because the focus of each peer-reviewed profile is on health and toxicologic aspects of each compound, each profile is structured in an attempt to focus its analysis on the compound’s public health implications and effects on human health as a result of exposure, which “would allow a public health professional to make a real-time determination of whether the presence of a particular substance in the environment poses a potential threat to human health.”
Guided by this methodology, the ATSDR report suggests “minimal risk levels,” or MRLs, for four of the 14 perfluoroalkyl compounds reviewed. With regard to PFOA and PFOS—two of the more prominent PFAs found in the United States—the study finds that these substances can potentially be harmful to humans at levels approximately seven and 10 times lower, respectively, than the current EPA health advisory level of 70 ppt for drinking water. Specifically, the ATSDR report identifies the appropriate minimal risk level for PFOA at levels that equate to approximately 11 ppt and for PFOS at approximately seven ppt ‒ all in stark contrast to EPA’s current advisory level. The ATSDR further concluded that minimal risk levels for PFNA and PFHxS are supported at levels of 3 × 10–6 mg/kg/day (i.e., approximately 11 ppt) and 2 x 10-5 mg/kg/day (i.e., approximately 74 ppt), respectively. As to the remaining 10 PFA compounds examined in the report, the ATSDR determined that too little toxicity data existed to enable the agency to derive safe minimal risk levels. The ATSDR cautions, however, that its conclusions on the minimal risk levels “are not meant to support regulatory action,” but instead are meant to “acquaint health professionals with exposure levels at which adverse health effects are not expected to occur in humans.” Notably, the ATSDR cautions that studies do not clearly show whether PFAs cause cancer in humans.
Implications and Takeaways
Although the ATSDR’s report is not final, the underlying findings will only further call into question the findings and underlying science used to support EPA’s current advisory levels, as well as those being reviewed and implemented at the state level. While the levels suggested in the ATSDR report are more in accord with the findings of several states, such as New Jersey and Vermont, other states like Michigan have preliminarily adopted EPA’s non-enforceable lifetime health advisory levels of 70 ppt in drinking water. Further, how EPA and the federal government use the ATSDR’s findings to inform federal policy and potential regulation of these chemical substances may only give way to more disparate regulation at the state level, leaving behind a patchwork of regulation and enforcement. Indeed, a number of non-governmental organizations and interest groups are already using the newly released study as a rallying cry for more stringent standards and the implementation of uniform maximum contaminant levels (MCLs) for these substances at levels far below the federally recommended (advisory) levels. As the ATSDR report itself suggests, however, more research is required to more fully understand the impacts of perfluoroalkyl substances on human health and safety.
Despite the gaps in science and current regulatory uncertainty, businesses would be well served to begin examining their product and supply lines, as well as their historic operations, to better understand their prior involvement with perfluoroalkyl substances, and any associated potential vulnerabilities to enforcement actions or litigation. Businesses should also be aware that the emerging state-by-state patchwork of regulation could also provide further grounds for litigation and agency enforcement. For example, in March of this year, Washington state enacted legislation banning use of PFAs in paper food packaging. In early April, the New York Department of Environmental Conservation announced that it would require owners of remediation sites to test for PFAs. And New Jersey is currently aiming to adopt formal standards for PFOS, PFOA, and PFNA in drinking water of 13, 14, and 13 ppt, respectively, within the next few months.
EPA is holding the first in a series of public meetings (“Community Engagement Events”) on PFAS on June 25 and 26 in Exeter, New Hampshire, and it can be expected that ATSDR’s report will be a prominent topic of discussion as stakeholders discuss the classification and regulation of these chemical substances.
The ATSDR report remains open for public comment through July 23, 2018.