Explainer: What are PFAS?

Americans are becoming increasingly concerned about their exposures to a class of chemicals known as PFAS. Here’s a brief explanation of what PFAS are, how they’ve spread throughout the environment, and the implications for our health.

What are PFAS?

In 1938, Roy J. Plunkett was a young chemist working for DuPont.

While working in the lab, Dr. Plunkett stumbled into creating a new chemical compound—a waxy substance that proved remarkably resistant to water. It turned out to be a game-changer.

By 1942, the new compound was being used in gaskets and valves that helped Manhattan Project scientists enrich uranium for the first atom bomb. Large-scale production of Plunkett’s new chemical compound, which most of us know as Teflon, began soon after. But the non-stick and non-stain properties of this miracle substance also offered the allure of convenience. And so later on, Teflon and a spiraling number of variants began appearing in non-stick pans (less scrubbing!), stain repellant carpets (less cleaning!), and even cosmetics (improved texture and consistency!).

So PFAS began bringing us more convenience. But at what cost?

Today, nearly 15,000 chemical substances collectively known as PFAS—the scientific acronym for per- or polyfluoroalkyl substances—are in use throughout the American economy.

Why are PFAS called ‘forever chemicals’?

The superpower behind PFAS chemicals lies in their exceptionally strong bond of carbon and fluorine atoms, which, in turn, makes these chemicals exceptionally durable.

The super-strong carbon-fluorine bond is also what makes PFAS so effective in keeping the buttery grease from bleeding through your popcorn bag, the rain and snow from permeating your jacket, and your dental floss from getting stuck between your molars and bicuspids.

This powerful chemical bond also means that PFAS tend to remain as the toxic compounds they are once released into in the natural world. Unlike food waste, yard waste or paper goods, PFAS do not readily decompose when exposed to sunlight or water. Some PFAS can stay in our bodies for years.

That’s why the PFAS put into the environment five years, 10 years, or 20 years ago are still around. That’s also how they earned their nickname “forever chemicals.”

How have PFAS spread in the environment?

Because PFAS are so effective, they’re used in an astonishingly wide range of products and machines.

The auto industry has used PFAS in car engines as well as in the textiles, upholsteries, carpets and leather in the interior of our vehicles. Companies that make personal care products have used PFAS in dental floss, shampoos and cosmetics. Sporting goods companies have used PFAS in outdoor gear and ski wax.

So, if you add it all up, how many products contain PFAS? It’s impossible to say. Thousands, at least. Which helps explain in part why PFAS can be found almost everywhere in the natural environment.

How does PFAS get from the environment into our bodies?

There are three main pathways:

1. Direct exposure via personal care products and cosmetics
2. Through our food from food packaging, pesticides, and PFAS-laden sewage sludge spread on farmland
3. Through drinking water contamination from factories dumping directly into rivers and groundwater; burning and burying PFAS-laden products that have been thrown away; the direct use of PFAS products like certain firefighting foam (Aqueous Film-Forming Foam, AFFF) as it seeps into ground and well water; and industrial and residential waste sent to sewage plants, which is then either released to rivers or winds up in sewage sludge that is spread on farmland

It’s estimated that PFAS is in nearly half of America’s tap water, according to a U.S. Geological Survey study. They can be found in the blood of an estimated 98% of Americans, according to another study. They’ve even been found in fertilizer made from sewage sludge used to grow crops.

To sum up: For decades PFAS have been used in thousands of consumer and industrial products. And because these compounds never fully break down, they’ve kept accumulating, year after year after year, in our water, soil, air, food and bodies.

How could exposure to PFAS affect people’s health?

For decades, evidence has been piling up linking PFAS to a wide range of damaging effects to the health of people (not to mention the health of other species). While industry documents suggest that PFAS producers knew that these chemical compounds were dangerous as early as 1970, the risks didn’t become widely known until the 1990s. So far, studies have found links between PFAS exposures and health disorders including:

• decreased fertility,
• developmental delays in children,
• increased risk of some cancers, including prostate, kidney and testicular cancers,
• reduced ability of the body’s immune system to fight infections,
• interference with the body’s natural hormones, including an increased risk of obesity, and
• increased cholesterol levels.

More studies are ongoing. Time may reveal more health effects as more studies are done and more people are exposed to PFAS.

What can and should be done to reduce the PFAS threat to our health and environment?

For toxic chemicals like PFAS that persist over time and contaminate our water and health through numerous pathways, there is simply no safe way to “manage” their ubiquitous use in our economy.

That’s why Environment America, PIRG and other groups are working to phase out the use of PFAS chemicals wherever we can. In 2020, we convinced Congress to order the Pentagon to phase out the use of PFAS-laden firefighting foam on military bases. In 2022, we helped convince Columbia Sportswear to stop using PFAS in their clothes and other products. We also helped win restrictions on PFAS in everyday consumer products in a number of states, and we have bills pending in other states.

Until we turn off this toxic tap at the source, we are also taking several steps to help people reduce their exposure to harmful PFAS, including:

• educating Americans about ways to reduce their exposures to PFAS in consumer products,
• keeping PFAS out of pesticides that are sprayed on our food and
• petitioning governmental agencies to do more to keep PFAS out of our drinking water and food supply.

And we’re not stopping there. Using PFAS-contaminated fertilizer on crops can end up contaminating our food, too, and that’s why we’re also petitioning governors across the country to ban the use of PFAS-contaminated sewage sludge as fertilizer on American farms.