COVID-19 Resource Center

Putting out the PFAS Fire

December 15, 2020Article

What is PFAS?

Per- and polyfluoroalkyl substances (PFAS) encompass a group of man-made chemicals that include PFOA, PFOS, GenX, and many others. The most studied and pervasive chemical forms are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Despite the confusing and similar-sounding acronyms, products made with PFAS chemicals are ubiquitous environmental contaminants of considerable persistence. For example, PFOA has been used in the production of the chemical polytetrafluoroethylene (PTFE), best known by the commercial name Teflon, which was first synthesized in 1938 by a DuPont scientist and came into widespread use in the 1960s.[1]

GenX is the trade name for a technology that is used to make high-performance fluoropolymers (e.g., some nonstick coatings) without the use of perfluorooctanoic acid (PFOA). HFPO dimer acid and its ammonium salt are the major chemicals associated with GenX technology. GenX chemicals have been found in surface water, groundwater, finished drinking water, rainwater, and air emissions in some areas.[2]

Perfluorobutane sulfonate (PFBS) is one of a group of related chemicals known as perfluorochemicals (PFCs). PFBS has been used as a surfactant in industrial processes and water-resistant or stain-resistant coatings on consumer products such as fabrics, carpets, and paper. The 3M Company has been a major manufacturer of PFBS and products containing PFBS.[3]

All of the products containing PFAS chemicals are built to last (e.g. asbestos). Their indestructibility by design results in their persistence in the environment, dubbing them “forever chemicals.”

What products contain PFAS chemicals?

PFAS products can be found in widespread applications and industries, including:

  • Food packaging, food-processing equipment, and the food itself that was grown in PFAS-contaminated soil (pesticides) or water;[4]
  • Commercial household products, including stain and water-repellent fabrics (e.g. Scotch-Guard), nonstick products (e.g., Teflon), polishes, waxes, paints, cleaning products, surface coatings for carpets and furniture;[5],[6]
  • Firefighting foams (a major source of groundwater contamination at airports and military bases where firefighting training occurs) and waterproof apparel;[7],[8]
  • Workplace, including production facilities or industries (e.g., chrome plating, electronics manufacturing or oil recovery), waterproof textiles, and electrical wire casing, among many other products;[9],[10]
  • Personal care products like waterproof mascaras and eyeliners, sunscreen, shampoo, and shaving cream.[11]

Does the United States still produce PFAS-containing products?

The manufacture and use of PFOA, PFOS, and other PFAS products have decreased significantly in the United States due to a series of EPA-facilitated voluntary phase-outs by major manufacturers that occurred starting in 2000.[12]

While industrial releases of PFOA and related compounds have declined in the United States and other industrialized nations, China’s production has been increasing, and the country is now the largest emitter of PFOA in the world.[13]

After the phase-out of PFOA and PFOS in the United States, manufacturers began replacing them with different, but similar, chemicals, with claims of reduced toxicity and bioaccumulation. For example, 3M is developing a new line of fluorochemical surfactants based on PFBS. PFBS-based surfactants are potential replacements for PFOS-based surfactants. According to 3M, PFBS has an excellent Environmental, Health, Safety, and Regulatory (EHSR) profile. 3M believes PFBS-based surfactants, with only four perfluorinated carbon atoms, are a sustainable alternative to PFOS-based surfactants with eight perfluorinated carbon atoms. [14]

However, there are concerns that these alternatives to legacy PFASs may have the same problems as their older relatives.[15] Contamination in drinking water, typically localized and associated with a specific facility (e.g., manufacturer, landfill, wastewater treatment plant, firefighter training facility) and presence in living organisms, including fish, animals, and humans, where PFAS have the ability to build up and persist over time, makes the effects of PFAS a concern for all.[16]

What are the effects of PFAS exposure?

Exposure to PFAS can lead to adverse human health effects. Humans are exposed to PFAS from many sources, including food (both homegrown and store-bought), food packaging, drinking water, and more.

PFAS can concentrate in the bodies of humans and animals over time through a process known as bioaccumulation. Bioaccumulation refers to the process of toxic chemicals building up inside of an organism’s body.[17] This happens when a chemical is consumed or absorbed, and the body cannot catabolize or excrete it quickly enough; Mercury is a well-known chemical that will bioaccumulate in humans.[18] Therefore, for example, PFOA’s presence in the body can persist even after exposure stops. PFOA’s half-life (the length of time it takes for a substance to decrease to half of its original value) in humans is anywhere from over two to nearly four years, while other PFAS chemicals have been shown to have a half-life of over eight years.[19] There is also evidence that some PFAS chemicals can affect humans through biomagnification as well.[20] Biomagnification refers to the process of toxic chemicals increasing in concentration as they move throughout a food chain.[21]

In laboratory animal studies, effects of PFBS exposure included developmental effects (e.g., lower body weight, delayed development) and female reproductive effects in offspring of mothers exposed during pregnancy as well as changes in thyroid hormone levels and cellular changes to the kidneys. Studies of health effects from PFBS exposure in people are lacking, but will certainly gain traction as the science progresses.[22]

A concerning 2003 to 2004 survey by the U.S. government estimated that over 98 percent of the U.S. population had detectable levels of PFASs in their blood.[23] According to the CDC, as a result of their pervasiveness, more than 95 percent of the U.S. population has PFAS in their bodies.[24]

PFAS and COVID-19

Notwithstanding the confusion and pure bewilderment associated with the causes and treatment of COVID-19, it appears universally accepted that underlying conditions may exacerbate its effects. Now, a new Danish study currently under peer review has shown that elevated levels of a PFAS chemical compound were associated with more severe forms of COVID-19.[25] The research, which involved 323 patients infected with the coronavirus, found that those who had elevated levels of a chemical called PFBA were more than twice as likely to have a severe form of the disease.[26] Therefore, the successful uptake of any vaccine for COVID-19 could be hindered by widespread contamination from PFAS. Scientists warn some of these PFAS chemicals may reduce the effectiveness of certain administered vaccines. This impediment could cast a shadow over efforts to roll out a COVID-19 vaccine to impact any easement on the COVID-19 guidelines in America.[27]

In addition to worsening the effects of COVID-19, this pervasive group of chemical compounds is at the forefront of mass tort litigation – therefore, insurance companies and associated product manufacturers must prepare to defend against PFAS claims.

PFAS and Litigation - Causation

The scant science of PFAS effects on humans has prevented plaintiffs from establishing causation between exposure to PFAS and injury. In personal injury litigation brought against DuPont, a science panel convened for settlement purposes found “no probable link” for 18 diseases (including broad categories of diseases). The panel’s findings of a “probable link” between exposure to PFOA and high cholesterol, ulcerative colitis, pregnancy-induced hypertension, and kidney cancer were not found to demonstrate causation and the term “probable link,” was based on statistical association, not causation.[28]

The December 2018 Agency for Toxic Substances & Disease Registry draft Toxicological Profile, concluded that “[a]lthough a large number of epidemiology studies have examined the potential of perfluoroalkyl compounds to induce adverse health effects, most of the studies are cross-sectional in design and do not establish causality. Based on a number of factors… including the consistency of findings across studies, the available epidemiology studies suggest associations between perfluoroalkyl exposure and several health outcomes.”[29] Thus, the scientific consensus to date is that while there is “suggestive evidence” of carcinogenicity, “there is no conclusive evidence of causation for PFAS.”[30]

No prior litigation has presented the scope of exposure, risk, and industry liability that PFAS presents. As the science develops, the landscape for this litigation will evolve and change.


Authors: Edward P. Abbot (Partner-in-Charge, New York), Deena M. Crimaldi (Of Counsel, New York)


[28] C8 Science Panel, C8 Probable Link Reports, available at http://www.c8sciencepanel.org/prob_link.html.

[29] ATSDR, Toxicological Profile for Perfluoroalkyls at 5 (June 2018), available at https://www.atsdr.cdc.gov/toxprofiles/tp200-c2.pdf.

[30] ATSDR, Toxicological Profile for Perfluoroalkyls at 5 (June 2018), available at https://www.atsdr.cdc.gov/toxprofiles/tp200.pdf.