Few substances have reached the level of public notoriety as per- and poly-fluoroalkyl substances, known as PFAS for short. As public awareness has grown, they’ve been given the ominous name “forever chemicals” due to their persistence in the environment.

Associate Professor of Sociology and Paul Garrett Fellow Alissa Cordner, an environmental sociologist, has been a co-director of the PFAS Project Lab, a research group based mostly at Northeastern University, since 2014.

“They’re everywhere in consumer products,” Cordner said. “In this room, they’re certainly on this chair, they’re probably on this carpet. They’re probably in the wiring of this computer.”

PFAS comprise more than 14,735 compounds, according to the US Environmental Protection Agency (EPA). They have found use in applications from medical sheets, surgical stents, house shutters, to nonstick cookware and firefighting foams.

The usefulness of PFAS lies in the carbon-fluorine bonds that they definitionally contain: this bond is extremely strong—the strongest single bond in organic chemistry. PFAS also repel water and oil, in addition to being resistant to heat, making them useful for many applications in consumer goods, industry and beyond.

Fluorine is the most electronegative element on the periodic table, meaning it has a strong pull on bonded electrons when it forms bonds. Thus, when it forms a bond with carbon, it pulls extremely strongly on the electrons in the bond, dragging the electron density closer to it and forming a separation of charge, called a “dipole.” In other words, the fluorine pulls electrons toward it and becomes partially negative while the carbon remains partially positive.

This makes the bond extremely stable because it prevents other atoms from reacting with the carbon and replacing the fluorine bound to it. When multiple fluorines are bound to the same carbon atom, the bonds between that carbon and others in a carbon chain can actually be made stronger.

All of these factors lead to an extremely stable molecule, one that does not easily break down in nature. Some PFAS such as carbon tetrafluoride have a predicted atmospheric lifetime of 50,000 years, although not all PFAS last that long. They are also highly persistent in the human body.

“Because of the strength of that chemical, that carbon-fluorine bond, [it] is extremely difficult to break down. And so what you see with certain PFAS is half lives within the human body of four years, six years, eight years — I mean unheard of half lives in the human body,” Cordner said.

What substances can even be classified as a PFAS has become a topic of scientific debate. According to literature provided by Cordner, one working definition considers PFAS to be substances with 30% fluorine by atom count or contain a handful of substructures identified by the authors. Others take more general approaches and simply consider substances with at least single carbon bonded to two or three fluorines as PFAS.

Adding to this complexity are distinctions between different types of PFAS, such as divisions between long and short chain polymers — referring to the number of carbon atoms in a molecule. Cordner shies away from this distinction.

“I think rather than using the short chain or long chain, there are some other ways you can break it out in terms of the per- and polyfluorinated acids versus the other PFAS,” Cordner said. “The general takeaway that my research lab and I talk about is, rather than trying to divide things up, [how] can we think of PFAS as an overall class of chemistry [and] develop research approaches that are useful in understanding people’s overall PFAS exposure and environmental burdens of PFAS?”

Some PFAS have been linked to health effects including increased risk of cancer, increased cholesterol and diabetes, reduced immune system function, developmental effects and reproductive effects, according to the EPA.

These substances are also prevalent in the environment, including but not limited to drinking water, consumer products and waste sites, according to the EPA. The Agency for Toxic Substances and Disease Registry, a government agency founded in the 1980s to implement legislation protecting the public from hazardous waste, said “nearly all” people in the United States have detectable amounts of PFAS in their blood.

The Food and Drug Administration (FDA) is tasked with ensuring the safety of the US food supply.

“Although it is well-documented that PFAS are present throughout the environment, understanding exposure from food is an evolving area of science. There remains much to learn about which types of foods are more likely to contain PFAS,” an FDA spokesperson said in a statement to The Wire. “To date, the agency has tested nearly 1,300 samples from a wide range of foods collected for the FDA’s TDS [Total Diet Study] or collected as part of targeted sampling assignments. No PFAS have been detected in over 97% (788 out of 813 posted results) of the fresh and processed foods tested from the TDS to date.”

The FDA also highlighted that it has taken action against PFAS-containing products that may pose risks to the public in the past. After studies raised concerns about the human health effects of PFAS impurities in food packaging, the FDA contacted manufacturers of these products.

“Manufacturers voluntarily agreed in July 2020 to phase-out their sales of these compounds to packaging manufacturers. In February 2024, the FDA announced that all grease-proofing agents containing PFAS are no longer being sold by manufacturers for food contact use in the U.S. market. The completion of the voluntary market phase-out of these substances used on food packaging paper and paperboard eliminates the primary source of dietary exposure to PFAS from authorized food contact uses,” an FDA spokesperson said.

The Center for Disease Control and Prevention (CDC) has also been involved in documenting and researching PFAS. 

“Research is ongoing to understand the mechanisms of PFAS toxicity, and scientists are still learning about the health effects of exposures to mixtures of different PFAS,” a CDC spokesperson said in a statement to The Wire.

Senior Gabe Wasserman, who was an undergraduate research assistant for Cordner’s research lab, wrote his thesis on PFAS in structural (building) firefighters’ turnout gear, the protective clothing they wear to endure high temperatures and chemical exposure when extinguishing a blaze.

“I think firefighters are kind of like the heroes in our society. I think a lot of people feel that [if] this building started to burn, we would call them and they would risk their lives [to] save us,” Wasserman said. “And it feels really important that someone is looking out for them.”

Wasserman said that firefighters already face increased cancer risk from toxic substances they inhale while fighting fires, and the added risk of PFAS in their gear can cause other potential problems.

“Cancer is a big [issue]. Hormone disruption is another big one. PFAS are known to mess with hormones,” Wasserman said. “[PFAS exposure may be correlated with] low testosterone in firefighters, which then can lead to mental health issues in firefighters, which is another huge concern right now in the fire service.”

Although some progress has been made removing potentially carcinogenic PFAS from outer layers of turnout gear, Wasserman says that PFAS are still often used in the lining of turnout gear, on an inside layer called the “moisture barrier,” which prevents sweat and water from escaping from inside the suit.

“The moisture barrier is the component that has had the most trouble getting PFAS-free. [Only recently] the first PFAS-free moisture barrier [was developed],” Wasserman said. “The issue is that when I talk to a lot of these decision makers in the fire service, [a] lot of them are very hesitant to make that switch because PFAS-free gear is likely heavier, not as effective at keeping water and oil out. It’s [also] hotter.”

Wasserman noted that despite these reservations, he still sees demand for PFAS-free person protective gear for firefighters. 

“A lot of the decision makers I talked to felt very strongly that if something was released that met NFPA [National Fire Protection Agency] standards, they would want to make that switch. Others were a little bit more hesitant,” Wasserman said. 

Wasserman described a need for more legislation around PFAS in firefighting equipment, saying that firefighting equipment is regulated by non-legally binding standards set by the NFPA.

“In terms of the firefighting equipment side of things, there’s no [governmental] legislation that regulates PFAS found in the equipment,” Wasserman said. “My thesis argues that there needs to be more collaboration between occupational [and] environmental activists related to PFAS. [Then] we can get more legislation that pays attention to PFAS exposure from work, from occupations, because there’s just not a lot of focus on that right now.”

Cordner said that as public awareness of their dangers has grown, activism related to PFAS has risen as well.

“Overall in terms of PFAS, there’s been a total explosion in advocacy and in regulatory activity. [I] think a lot of it can be traced back to [testing in] 2013 to 2015. And so that greater awareness of how many contaminated sites around the country led to a lot of community residents becoming very concerned about PFAS in their drinking water. And that grassroots activism combined with an increasingly robust understanding of the science behind PFAS toxicity [fed] into greater regulatory attention,” Cordner said.

This activism has led to class-action lawsuits against PFAS manufacturers and, in some cases, legislation, such as regulations on PFAS in consumer products in Maine.

Cordner recently published a paper mapping carceral facilities downstream of known or presumptive PFAS sources, finding that 5% of US carceral facilities are downstream of a known PFAS source, and 47% are downstream of a presumptive source. These facilities house over a million individuals including more than 12,000 juveniles, who the EPA has highlighted as at higher risk than adults for PFAS-related health effects.

“There are a lot of potential inequalities with PFAS exposure, but it’s very hard to quantify because the testing is pretty uneven,” Cordner said. “I think the quantitative research matters because it’s addressing these underlying questions of justice. And one of the arguments about contaminated drinking water is that people can always filter … but if you’re in a carceral facility, you have little to no control over the water and food that you are consuming.”

Cordner said that she hopes the study will spur more research and encourage carceral facilities to test water for PFAS.

The field of PFAS and related regulation is evolving rapidly; on April 10, the EPA announced the first ever national standards for PFAS in drinking water in the United States.

These standards include plans to reduce PFAS exposure for 100 million people, and set limits on the amount of PFAS in the low part per trillion level, although the exact amount varies based on the type of PFAS.

As regulation expands along with understanding of the health effects and prevalence of PFAS, only one thing is clear: PFAS are here to stay.

The EPA did not respond to a request for comment prior to publication.

A note on this article’s inclusion into Circuit: It may seem strange to include PFAS in a magazine themed “from the archives,” but I see them as oddly in opposition to archives: they raise important questions about the processes of decay we take for granted, that fuel us, that construct our DNA covalent-bond-by-covalent bond. Rather, they insert themselves into the fabric of our being and stick there, a reminder of the magic of chemical engineering, and the limits of our measurement systems. What purpose is there for an archive against the mathematical limit of forever? What purpose can there be except totalization, abstraction, the closing of a feedback loop? Perhaps they’ll outlive the archive, and perhaps even us.