What’s the difference between PFAS, PFOS, PFOA, PTFE, and GenX? (2024)

PFAS are a group of manmade chemicals used in a vast number of consumer and industrial products. They’re often referred to as “forever chemicals,” because most don’t break down. Use this guide to understand PFAS and how to limit your exposure.

What does PFAS stand for?

PFAS stands for per-and polyfluoroalkyl substances, which contain a strong carbon-fluorine bond that allows them to accumulate over time in the environment and in the bodies of animals and people, posing health risks. PFAS chemicals might also be thought of as “everywhere chemicals,” since they’ve become so common in the products we use every day.

Where does PFAS contamination come from?

Chemical plants and other industrial facilities, along with landfills and treatment plants, are among the common sources of PFAS contamination. (Credit: Wikimedia Commons)

Manufacturing processes and waste storage and treatment sites release PFAS into the air, soil, and water. The Environmental Working Group (EWG) has identified 41,828 industrial and municipal sites in the U.S. that are known or suspected of using PFAS. Among the industrial facilities the group pointed to are petroleum stations and terminals, chemical manufacturers, commercial printers, plastics and resin manufacturing sites, paint and coating manufacturers, semiconductor manufacturers, makers of metal products and electrical components, and electroplating and polishing.

EWG recently released an additional report based on EPA data that found PFAS may be discharged by more than 1,500 U.S. textile mills. Landfills and waste disposal facilities, along with sewage and waste treatment plants, are other common sources of contamination.

In addition, military bases and airports are major contributors to PFAS contamination, mostly from training and testing exercises using firefighting foam. EWG mapped 385 U.S. military installations with PFAS contamination and several hundred more that are suspected to be contaminated. Many nearby communities also suffer groundwater and drinking water contamination as a result of their proximity to these facilities.

There are estimated to be more than 9,000 PFAS chemicals. Some of the most common include Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA), also known as C8. These chemicals were once widely used in substances like fabric and leather coatings, household cleaning products, firefighting foams, and stain-resistant carpeting. Although manufacturers have phased out their use in Canada and the U.S. over the past two decades, they remain ubiquitous in the environment—and in our bodies. Dupont developed GenX as a replacement for PFOA in 2009, but subsequent studies of GenX have also raised health concerns.

Polytetrafluoroethylene (PTFE), along with C8/PFOA, were used to produce Teflon, the non-stick chemical coating manufactured for decades by Dupont and now Chemours, which Dupont spun off in 2015.

What are the dangers of PFAS?

PFAS exposure begins before birth and the chemicals build up in our bodies over time. (Credit: Silvio Lucchini/flickr)

PFAS are in the blood of nearly all Americans, and testing of umbilical cord blood and breast milk indicates that exposure begins before birth. Some PFAS bioaccumulate—build up—which means even low exposures are cause for concern over time as our bodies accumulate more and more of them. PFAS bioaccumulation also occurs in non-human organisms, including fish and other human food sources, which eventually end up in people. That’s another reason protecting the environment from PFAS contamination—and monitoring PFAS levels—is so important.

PFAS are endocrine disrupting chemicals, meaning they interfere with our hormone systems. When an external chemical interferes with our hormone systems, it can lead to changes in our bodies and brains capable of causing disease and, in some cases, even death.

Research links PFAS to health problems including kidney and testicular cancer, liver and thyroid problems, reproductive problems, pregnancy-induced high blood pressure, low birthweight, and increased risk of birth defects, among others. PFAS has also been linked to changes in cholesterol levels and in the timing of puberty. Evidence of PFAS impacts on immune function is another growing concern, and studies have found some PFAS may lower vaccine effectiveness.

PFAS contamination also has an environmental justice dimension, as low-income communities and communities of color are often more likely to be located near sites of PFAS contamination, increasing their health risks.

Why is PFAS getting so much attention now?

For decades, a chemical plant in North Carolina dumped PFAS-contaminated waste into the Cape Fear River, a source of drinking water. PFAS is linked to serious health conditions, including cancer. (Credit: Rich Brents/Unsplash)

Although there is evidence that makers of PFAS were aware of their adverse health effects as far back as the 1950s, the general public was largely uninformed. The companies kept health research from employees and the public for decades, as EWG chronicles in this timeline. We know much more about the health impacts of PFAS today.

In 1998, the company 3M, maker of the Scotchgard water- and stain-repellent material, alerted the EPA that PFOS builds up in blood and had been detected in blood samples of people across the United States who weren’t exposed on the job. Data received from 3M eventually prompted greater EPA scrutiny of PFAS.

While almost everyone has PFAS in their bodies today, those living or working near PFAS manufacturing, industry, or disposal sites face heightened risk of health problems.

Some 80,000 local residents of Parkersburg, West Virginia, settled a lawsuit against Dupont, which was found to be knowingly contaminating ground and river water with PFAS chemicals for decades, despite evidence that the chemicals were toxic to humans and animals. A subsequent study found a likely link between PFOA/C8, and several serious health conditions, including cancer.

For more than three decades, a chemical manufacturing plant outside of Fayetteville, North Carolina owned by Dupont and later Chemours dumped PFAS-contaminated waste into the Cape Fear River. Not until 2017 did the public learn they were consuming water contaminated with a newer PFAS, GenX, and other lesser-known PFAS compounds.

In the 1960s, the Wolverine Worldwide Tannery in Rockford, Michigan contaminated land, groundwater, and the Rogue River—once Rockford’s drinking water source—with PFAS-laden leather manufacturing waste. The EPA is now considering whether to designate the former tannery and its old dump as federal Superfund sites.

The group Physicians for Social Responsibility recently reported that oil and gas companies used PFAS and substances that could degrade into PFAS at more than 1,200 fracking wells across six states—Arkansas, Louisiana, Oklahoma, New Mexico, Texas, and Wyoming—between 2012 and 2020.

Where do you find PFAS?

PFAS have been used around the world since the 1950s in a wide variety of consumer goods. Today, they can be found in products like firefighting foam, non-stick cookware, cosmetics, and materials that protect against grease, oil, and water, such as stain-resistant carpeting and fabrics, food packaging, and water-repellent clothing. So whether we’re camping, hiking, hunting, fishing, cooking, putting on makeup, enjoying a takeout meal, or playing with our kids on the living room floor, PFAS have infiltrated everyday life.

Testing for PFAS

Researchers are finding PFAS in a wide variety of consumer goods — including products in which PFAS are not intentionally added.

A testing collaboration between EHN.org and wellness site Mamavation has found evidence of the chemicals in clothing, food, and makeup. See additional testing at Mamavation's Product Investigation page, including bamboo flooring, period underwear, and parchment paper.

PFAS in food

Takeout containers, pizza boxes, microwave popcorn bags, and non-stick cookware are all ways that food can become contaminated with PFAS. (Credit: Jordan Nix/Unsplash)

Food packaging, like takeout containers and wrappers, pizza boxes, french fry containers, hamburger wrappers, and microwave popcorn bags are all common means of PFAS food contamination. Even supposedly environmentally-friendly compostable bowls sometimes contain PFAS. The Food and Drug Administration has not restricted use of PFAS in food packaging, leaving it up to states and the public to protect consumers.

Non-stick cookware is another way that PFAS can enter our food and air. Although PFOA has been phased out in the U.S, non-stick cookware still contains alternatives that may be harmful to health. Labels claiming PFOA-free don't necessarily mean cookware is safe. PFAS-free is the safest choice.

PFAS in cosmetics

Makeup and personal care products like dental floss may contain PFAS even if none are listed among the ingredients. (Credit: Carlos Martinez/Unsplash)

A growing body of research is turning up evidence that personal care products like cosmetics—even supposedly “green” cosmetics—contain PFAS. A recent peer-reviewed study found high levels of organic fluorine, an indicator of PFAS, in more than half of 231 makeup and personal care samples, including lipstick, eyeliner, mascara, foundation, concealer, lip balm, blush, and nail polish. It’s also been found in some types of dental floss designed to glide more easily between teeth.

PFAS in clothing and home goods

New research suggests people may absorb PFAS through their skin from stain-resistant carpeting and water- and stain-repellent textiles. (Credit: Picsea/Unsplash)

Testing by EHN and other organizations has found indicators of PFAS in everything from athletic and yoga clothes to period underwear to stain- and water-repellent clothing. PFAS indicators have also been detected in popular kitchen linens and bedding and stain-resistant carpeting and upholstery. PFAS from textiles can build up in household dust, and emerging evidence suggests that we could absorb some compounds through our skin. Treated jackets and other items can also contaminate water supplies, as PFAS run off them in the wash.

PFAS in firefighting foams

Firefighting foams used on military bases, airports, and burn sites are a big source of PFAS contamination. (Credit: Wikimedia Commons)

According to the Green Science Policy Institute, the majority of known PFAS-contaminated sites in the U.S. are related to the use of firefighting foam. These sites include military sites, airports, fire-training areas, and past burn sites.

PFAS in landfills and wastewater

Landfill waste washes PFAS into soil and waterways. (Credit: Alexander Schimmeck/Unsplash)

Discarded products such as clothing, carpet, bedding, and food packaging can release PFAS into landfills, where rainwater moves it (along with other chemicals), creating a concentrated toxic waste that infiltrates soil and nearby water sources like rivers and lakes. Typical landfill waste treatment systems do not remove PFAS.

PFAS from products we use everyday get washed down the drain and flow to wastewater treatment plants. Most wastewater plants aren’t advanced enough to remove PFAS, so the chemicals remain in treated water and biosolids (recycled sewage) that are sometimes used in agriculture. This can end up contaminating agricultural lands, and PFAS then return to our kitchen table via fruits, vegetables, and meat.

PFAS in drinking water

PFAS has been detected in drinking water systems across the U.S. (Credit: Bluewater Sweden/Unsplash)

PFAS contamination in the water supply is widespread. Research by EWG has found PFAS contamination in drinking water systems across all 50 states and two U.S. territories, Guam and Puerto Rico. But the full extent of the problem remains unknown.

Bottled water constitutes another emerging PFAS risk. A 2021 study led by Johns Hopkins researchers found 39 out of 100 bottled waters tested contained PFAS. The Food and Drug Administration has not set PFAS limits for bottled water.

Are PFAS alternatives safer?

An international group of scientists has called for a phase-out of PFAS according to how essential the chemicals are. In short, things like cosmetics and most other personal care products that can be made without PFAS should be. In other cases, there may be safer substitutes available, such as for waterproof jackets and equipment.

Right now, though, the most common substitutes for PFAS are other PFAS chemicals. So-called short-chain PFAS have been developed as supposedly safer alternatives to the older long-chain PFAS. That’s what happened in the 1990s, when 3M struck a deal with the EPA to phase out PFOS in Scotchgard products. The company replaced it with an alternative that lingers in people’s bodies for significantly less time, decreasing human exposure. The EPA subsequently created a voluntary stewardship program for PFOA that encouraged companies to phase out its use and develop safer alternatives.

Researchers from around the world have expressed concerns, however, that more study is needed to determine whether current PFAS alternatives are truly safe. Even if they leave the human body sooner, they still build up in the environment, which could continue to create serious pollution problems over time.

What are governments doing to protect people from PFAS?

Even now, there are no federal standards limiting PFAS discharges. In 2021, the EPA issued a “PFAS roadmap” with a timeline for setting drinking water and wastewater treatment standards, health assessment protocols, and hazardous substance designations for several PFAS chemicals, including PFOA and PFOS.

Congress is currently considering comprehensive PFAS legislation. The U.S. House of Representatives passed the PFAS Action Act of 2021 and advanced it to the Senate. A separate House bill, The Clean Water Standards for PFAS Act, would require water discharge limits on PFAS from chemical manufacturers, paint, paper, plastics, electrical components, textiles, leather tanning, metal finishing and electroplating companies.

Growing concerns about the health and environmental impacts of PFAS is prompting action at the state level as well. A recent analysis found that at least 32 U.S. states are considering more than 210 bills that would ban or restrict PFAS, including in personal care products, clothing, and food packaging.

Europe is moving faster. The European Union is considering a ban on thousands of PFAS chemicals except when their use is deemed essential. If successful, a final agreement could come by 2025.

What can you do to avoid PFAS?

Using stainless steel, cast iron, glass, or ceramic cookware instead of non-stick pots and pans is one way to avoid PFAS exposure. (Credit: Justus Menke/Unsplash)

Completely avoiding PFAS is almost impossible, and the cost of cleanup is enormous. But there are things you can do to reduce your risk and advocate for change.

Avoid water and stain-repellent carpeting and household textiles, such as curtains, furniture upholstery, bedding, table cloths, and napkins.

Limit use and purchase of “waterproof,” “water-resistant,” and “stain-resistant” clothing and other products, and “anti-fog” eyeglass sprays and wipes

Avoid food packaged in greaseproof bags or containers. As an alternative, use your own glass containers for takeout and leftovers. Encourage restaurants to ditch food containers and packaging containing PFAS. Skip microwave popcorn from PFAS-treated bags.

Be aware that not all compostable packaging is PFAS-free: choose BPI-certified packaging to be sure, and ask about it at restaurants that use compostable containers.

Cook with stainless steel, cast iron, glass, or ceramic cookware instead of non-stick options.

Read personal care product and cosmetic labeling carefully and avoid those with “perfluor-,” “polyfluor-,” “PTFE,” or Teflon on the label.

Find out if your water source has been tested for PFAS. If it contains PFAS, or if it hasn’t been tested, a water filter might be a good purchase. However, be aware that not all water filters are equally effective; a 2020 Duke University study found that reverse osmosis filters and two-stage filters performed best at eliminating PFAS.

If you drink bottled water, try to purchase water labeled “purified,” rather than spring water.

And, of course, stay in touch with EHN. We will continue to report on PFAS. Our ongoing testing and coverage of PFAS contamination in food packaging and common consumer goods, coupled with reporting on policy and regulation, seeks to hold companies, political leaders, and agency officials accountable for protecting the public.

We also have a rich archive of PFAS coverage from U.S. and international news organizations. Enter “PFAS” in our search tool in the upper right-hand corner of our homepage to find all of it.

Banner photo credit: engin akyurt/Unsplash

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