Key takeaways:
Known as “forever chemicals,” per- and polyfluoroalkyl substances (PFAS) are human-made chemicals. For decades, they’ve been used in consumer and industrial products.
Research has found that even low levels of these chemicals may cause health issues, such as cancer, lower immunity, and liver damage.
It’s hard to avoid PFAS altogether. But there are ways to lower your exposure, including by using water filters and choosing PFAS-free products. You can also contact your local or state government to request regular water testing.
You may have heard about “forever chemicals,” likely in conjunction with potential health risks. But what exactly are they, and how might they affect your health?
The origin story of forever chemicals dates back to the 1940s, with the invention of the nonstick pan. The original pan used Teflon, a chemical that gave the pan its water- and oil-resistant properties. Since the invention of Teflon, more than 14,000 similar forever chemicals have been used.
In 2024, the Environmental Protection Agency (EPA) set national safety limits for six types of per- and polyfluoroalkyl substances (PFAS) in drinking water. These new standards acknowledged the possible health risks of PFAS. Now, public water systems are required to test for these chemicals — and take steps to remove them over time.
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So, how worried should you be about PFAS? Here’s a breakdown of what you need to know.
What are forever chemicals (PFAS)?
The term “forever chemicals” refers to per- and polyfluoroalkyl substances (PFAS). This is a large group of human-made chemicals. You can find PFAS in many common, everyday products. They’re used for many different purposes — from making products water-resistant to protecting pipes from corrosion. PFAS are also found in drinking water.
Some examples of PFAS include:
Perfluorooctanoic acid (PFOA)
Perfluorooctane sulfonic acid (PFOS)
Perfluorononanoic acid (PFNA)
Perfluorohexane sulfonic acid (PFHxS)
Hexafluoropropylene oxide dimer acid (HFPO-DA, or Gen X)
Perfluorobutane sulfonate (PFBS)
Perfluorohexanoic acid (PFHxA)
Perfluorodecanoic acid (PFDA)
Perfluorododecanoic acid (PFDoA)
Why are they called “forever chemicals?”
PFAS have earned the name “forever chemicals” because of how long they take to break down. Their chemical bonds are so strong that they can take thousands of years to degrade in nature. In the human body, they can build up indefinitely. So, for all intents and purposes, they last forever.
That said, scientists have been testing ways to destroy certain forever chemicals and remove them from drinking water. Some of these methods show promise. But researchers are still learning about the effectiveness and practical use of these methods.
Where can you find forever chemicals?
In short, you can find PFAS everywhere. Research points to decades of manufacturing with forever chemicals. An analysis by the CDC reported PFAS in the blood of an estimated 97% of the U.S. population. And, while the use of some forever chemicals has declined significantly since 2002, it’s possible that we’re continually exposed to new PFAS. The widespread use of PFAS can make it difficult to accurately monitor the level of exposure we face.
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Examples of products containing forever chemicals include:
Drinking water
Soil
Stain- or water-repellent clothing
Stain-resistant furniture and carpeting
Firefighting foam
Shampoo
Dental floss
Bandages
Makeup
Wrappers used for fast food and baked goods
Paint
Chemical facilities
Electronics
Paper
Some cookware and bakeware
Cleaning supplies
Fish and other wildlife
Are forever chemicals unsafe?
Forever chemicals are likely unsafe. It may depend on the level of exposure and types of PFAS, among other factors.
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Scientists are still learning about how forever chemicals affect people. There’s a strong body of evidence linking PFAS to a variety of health issues. But it’s important to note that a large portion of this research comes from studies done in animals. And most of these studies exposed the animals to higher amounts of forever chemicals than humans may experience. In other words, the findings from animal studies may not apply to humans.
That said, there’s a lot we still don’t know about forever chemicals. Because they can collect in our bodies over time, long-term effects are unclear.
What health problems are linked to forever chemicals?
A variety of negative health effects have been linked to forever chemicals. But the available evidence suggests there’s a likely association between forever chemicals and the following six health conditions.
1. Cancer
Some evidence suggests a link between PFAS exposure and kidney, prostate, and reproductive cancers in people who work in places with forever chemicals or live in areas where the water or soil are contaminated with them. But what about in the general population? Here there also seems to be a link between exposure to PFAS in drinking water and cancer risk.
Drinking water contaminated with PFAS may increase the risk of several types of cancer, including cancer of the:
Digestive system (colon, esophagus, liver, gallbladder)
Lung
Thyroid
Kidney
Bladder
Brain
Skin
Soft tissue
2. Lowered immunity
In 2016, the National Toxicology Program issued a statement saying that two types of forever chemicals — PFOS and PFOA — are likely an immune hazard to humans. This is because these substances may lower immunity. This finding is based on research in both humans and animals, but more of the research was on animals.
3. Preeclampsia in pregnant people
A recent study suggests that even low exposure to forever chemicals may raise the risk of preeclampsia (high blood pressure during pregnancy). The study’s researchers pointed out that most research looked at preeclampsia risk in pregnant people who were exposed to higher levels of PFAS. So, additional research is needed. But it’s possible that it might not take high levels of forever chemicals to pose such risks.
4. Impact on fetal development
The relationship between PFAS exposure during pregnancy and growth and development in fetuses is a complicated one. Studies report varying findings around body weight, height, and growth. But a review of 18 studies in humans found that prenatal exposure to forever chemicals leads to reduced fetal growth.
5. Higher cholesterol levels
Studies on larger populations affected by forever chemical contamination found a link between PFAS and a higher risk of elevated cholesterol levels. And research that looked at young adults in a Mediterranean region — where diet and lifestyle are different from Western eating patterns — found a similar link between PFAS exposure and high cholesterol.
6. Liver damage
A collection of 111 studies (25 of which were done on humans) have linked PFAS exposure to liver problems.
The animal and human studies showed similar findings. People and rats with higher levels of forever chemicals in the blood also appeared to have higher liver enzymes. Having higher liver enzymes is a sign of liver damage.
Forever chemicals in drinking water
Drinking water is one of the most common sources of exposure to forever chemicals. More than 200 million people across all 50 U.S. states are likely affected by contaminated drinking water. Communities hit hardest are often those near military bases. This is because firefighting foams with PFAS have been used there for decades to fight jet-fuel fires.
In 2024, the Environmental Protection Agency (EPA) established legally-enforceable levels for six PFAS in drinking water. For the two most common types of PFAS (PFOA and PFOS), the EPA’s goal is to eliminate it in drinking water altogether. They set a current legal limit at 4 parts per trillion (ppt).
The EPA expects that over time, this final rule will reduce PFAS exposure in drinking water for approximately 100 million people living in areas with the highest amounts in their drinking water.
Keep in mind, these are interim guidelines — meaning that as the science evolves, these numbers can change.
Forever chemicals water contamination lawsuits
Individuals and many U.S. states have sued chemical manufacturers — including DuPont and firefighting foam manufacturer 3M — for contaminating water and soil with forever chemicals, despite the known health risks. Many of these chemical companies have paid out settlements to help remove forever chemicals from the environment. Most recently, in August 2025, DuPont and two other companies settled a lawsuit with the state of New Jersey. The companies will pay up to $2 billion to remove PFAS from four sites.
In 2023, Consumer Reports estimated that over 4,000 lawsuits had been filed. Many people filing these lawsuits attributed illness and deaths of loved ones to years of drinking contaminated water.
How can you avoid forever chemicals?
To limit your exposure to forever chemicals, you can:
Look for PFAS-free clothing and other products. Avoid products that contain ingredients that start with "fluoro" or "perfluoro."
Use water filters. Using a water filter at home can help remove some PFAS from your tap. The EPA recommends reverse osmosis filters, which are 90% effective in removing many forever chemicals.
Contact your local water utility company. If a public water system services your home, you can ask your local water utility company to test the drinking water. Then, compare it to your state’s or the EPA’s standards for safe levels of PFAS. You can also reach out to your state’s environmental or health department to find out what steps they’re taking to address forever chemicals.
Eat freshly prepared food at home as much as possible. Research has found a link between people who eat more fast food and/or restaurant takeout and higher exposure to forever chemicals.
Avoid eating contaminated fish. The best way to do this is to find out where the fish came from. Contact your state or tribal fish advisory programs to determine which bodies of water have high PFAS.
Are forever chemicals being regulated?
Yes, state governments have been setting guidelines to help control PFAS. And, in 2024, for the first time, the EPA has set legally-enforceable maximum PFAS levels for drinking water.
Other measures to regulate forever chemicals include:
In 2024, the FDA stopped authorizing the use of grease-proofing substances, like those used in microwave popcorn packaging, takeout containers, and food wrappers.
In 2023, the Biden administration’s Bipartisan Infrastructure Law made $2 billion in funding available to address forever chemicals and newer contaminants in rural and disadvantaged communities across the country.
In 2023, the EPA proposed a regulation that prevents companies from using around 300 forever chemicals that haven’t been in current use without a full review.
In 2021, Congress passed the bipartisan Keep Food Containers Safe from PFAS Act, which bans PFAS in food packaging.
Frequently asked questions
Cast iron pans, glass bakeware (unpainted), and stainless steel pans don't contain forever chemicals — and they’re less likely to release metals into foods. This makes them the safest cookware to use. To limit your exposure to unsafe cookware, avoid using damaged or old pieces, and buy new cookware made in the U.S. This is because all new cookware sold in the U.S. has to meet current FDA safety regulations. Finally, make sure to cook at temperatures under 500°F, since temperatures higher than this can cause cookware to degrade.
There's no medically-approved treatment for removing PFAS from the body. Finding ways to reduce PFAS exposure is the most important thing you can do to protect yourself. That said, research suggests that consuming soluble fiber regularly may help reduce the body’s levels of PFOS and PFOA, two of the most common types of PFAS. It's also possible that the cholesterol drug cholestyramine can help remove forever chemicals from the body. But it's important to note that the data on cholestyramine comes from a small study on people with high levels of PFAS concentration in their blood. So, more research here is needed.
Cast iron pans, glass bakeware (unpainted), and stainless steel pans don't contain forever chemicals — and they’re less likely to release metals into foods. This makes them the safest cookware to use. To limit your exposure to unsafe cookware, avoid using damaged or old pieces, and buy new cookware made in the U.S. This is because all new cookware sold in the U.S. has to meet current FDA safety regulations. Finally, make sure to cook at temperatures under 500°F, since temperatures higher than this can cause cookware to degrade.
There's no medically-approved treatment for removing PFAS from the body. Finding ways to reduce PFAS exposure is the most important thing you can do to protect yourself. That said, research suggests that consuming soluble fiber regularly may help reduce the body’s levels of PFOS and PFOA, two of the most common types of PFAS. It's also possible that the cholesterol drug cholestyramine can help remove forever chemicals from the body. But it's important to note that the data on cholestyramine comes from a small study on people with high levels of PFAS concentration in their blood. So, more research here is needed.
The bottom line
Scientists are still learning about the health effects of per- and polyfluoroalkyl substances (PFAS) in people. But these "forever chemicals" are linked to a variety of health problems, even at low levels.
It’s very difficult to avoid forever chemicals altogether, given how widely they’re used. The Environmental Protection Agency (EPA), state governments, and certain companies are taking action against PFAS. But you can also take steps to protect yourself. Using water filters and looking for products and foods made without PFAS is a place to start.
Why trust our experts?
References
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