Per- and Polyfluoroalkyl Substances (PFAS)

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that have been used since the 1950s. 

Concerned about PFAS in your drinking water?

If you do not live near a site of environmental contamination, it is unlikely that PFAS are a problem in your drinking water. However, if you live near a site of PFAS contamination, you should connect with your local municipality and the Wisconsin Department of Natural Resources (DNR) to learn about available resources. To find out whether you live near a PFAS site, view this map.

If PFAS has been found in your drinking water, this brochure (P-03012 – English, Spanish, Hmong) describes treatment devices that can be used to remove PFAS from your water.

The Centers for Disease Control and Prevention (CDC) Agency for Toxic Substance and Disease Registry (ATSDR) has a PFAS family tree that shows how PFAS contain various polyfluoroalkyls and perfluoroalkyls.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most widely produced and studied of these chemicals.

Although some of these substances have been phased out of production, such as those through the PFOA stewardship program, they may still be found in everyday consumer products, such as some grease-resistant paper, nonstick cookware, stain resistant fabrics, cleaning products, and other personal care products, like shampoo and nail polish.


How are we exposed to PFAS?

PFAS have been used in non-stick cookware, water-repellent clothing, stain resistant fabrics and carpets, some cosmetics, some firefighting foams, and products that resist grease, water, and oil.

Over half of our contact with PFAS are estimated to come from food. The main ways people come into contact with PFAS are:

  • Eating food that was packaged in material that contains PFAS.
  • Eating fish caught from water contaminated by PFAS (PFOS, in particular).
  • Drinking contaminated water.
  • Accidentally swallowing contaminated soil or dust.

People may also come into contact with PFAS by using some consumer products, such as non-stick cookware, stain resistant carpeting, and water repellant clothing.

How can PFAS affect our health?

Humans and animals react differently to PFAS, and not all effects observed in animals may occur in humans. It's therefore important for you to know:

  • Scientists have ways to estimate how the exposure and effects in animals compare to what they would be in humans.
  • What scientists learn from this process helps them decide how to protect people from harm caused by chemical exposure.

Scientists are still learning about the health effects that various PFAS can have on the body. The more widely used substances, like PFOS, PFOA, perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA), have been studied more than other PFAS.

A large number of studies in people have examined possible relationships between levels of PFAS in blood and harmful health effects in people. However, most of these studies analyzed only a small number of chemicals, and not all PFAS have the same health effects. This research suggests that high levels of certain PFAS may:

  • Increase cholesterol levels.
  • Decrease how well the body responds to vaccines.
  • Increase the risk of thyroid disease.
  • Decrease fertility in women.
  • Increase the risk of serious conditions like high blood pressure or pre-eclampsia in pregnant women.
  • Lower infant birth weights; however, the decrease in birth weight is small and may not affect the infant’s health.

One way to learn about whether PFAS will harm people is to conduct studies in lab animals. Most of these studies have tested amounts of PFOA and PFOS that are higher than levels found in the environment. These animal studies have found that PFOA and PFOS can cause damage to the liver and the immune system, birth defects, delayed development, and newborn deaths in lab animals.

Most people in the U.S. have PFAS in their blood, similar to the low levels observed in blood for other industrial compound classes like flame retardants and plasticizers. While you can do a blood test to determine the amount of PFAS in your body, there is not enough research to determine the level at which we would expect to see health problems. ATSDR has more information on blood testing.

How can we evaluate our risk from PFAS in drinking water?

DHS recommends groundwater standards to protect people from substances that can be found in drinking water. 

To date, DHS has recommended groundwater standards for 18 PFAS. These recommendations are based on available scientific information 

Did you test your drinking water for PFAS? 

This fact sheet explains how you can use this online tool to evaluate risk from PFAS in your drinking water (P-03212 - English, Spanish, Hmong). 

If PFAS has been found in your drinking water, this brochure describes treatment devices that can be used to remove PFAS from your water (P-03012 - English, Spanish, Hmong). 

and are set to protect everyone from the health risks of PFAS in drinking water. Sometimes our recommendations are also called drinking water health advisories.


Summary of DHS' Recommended Groundwater Standards for PFAS

PFOA = 20* PFNA = 30 PFUnA = 3,000
PFOS = 20* PFHxS = 40 PFBA = 10,000
FOSA = 20* GenX = 300 PFTeA = 10,000
NEtFOSA = 20* PFDA = 300 PFHxA = 150,000
NEtFOSAA = 20* PFDoA = 500 PFODA = 400,000
NEtFOSE = 20* DONA = 3,000 PFBS = 450,000

* DHS recommends a combined standard of 20 ng/L for PFOA, PFOS, FOSA, NEtFOSA, NEtFOSAA, and NEtFOSE.  All recommendations are shown as nanograms of PFAS per liter of water (ng/L), which is equivalent to parts per trillion (ppt).

More information on these recommendations can be found on our Cycle 10 and Cycle 11 pages. 

The hazard index is used to evaluate the risk from exposure to mixtures of PFAS.

The hazard index is an approach commonly used by environmental health professionals to evaluate the health risk from exposure to a mixture of related chemicals. DHS had used a hazard index approach in the past to assess health risks from exposure to mixtures of other groundwater contaminants, such as certain pesticides and volatile organic compounds (VOCs).

This video describes the hazard index approach and steps people should take to reduce their exposure to mixtures of PFAS.

This video is also available in Spanish and Hmong

How can I protect myself and my family from PFAS? 

It’s not practical to completely reduce our exposure to these chemicals as they are so common and present in our environment, but we can take simple actions to limit our contact with them: 

Use a drinking water source that has PFAS levels below DHS' recommendations.

Using a water source that has PFAS levels below DHS' recommended standards for drinking, mixing beverages (such as infant formula), and making foods that take up a lot of water (such as oatmeal, soup, or rice).  This may include bottled water that has been purified or filtered, water from a treatment system certified by ANSI/NSF Standards 53 or 58 to reduce PFAS (see this brochure, P-03012), or water from a source that have been tested for PFAS and do not contain PFAS above the recommended standards.

You may use your tap water for doing laundry, washing dishes, brushing teeth and filling your swimming pool. However, to reduce the chance of accidental ingestion of small amounts of PFAS, remind swimmers not to swallow pool water.

Use water with PFAS levels below DHS' recommendations for watering fruit and vegetable gardens.

View these facts and tips, P-03111, to learn more about plant uptake of PFAS and how to reduce PFAS exposure from gardening in areas with known or suspected PFAS contamination. 

Follow Wisconsin's fish consumption advisories. 

By following the consumption advisories currently in place where you fish, you will reduce potential health risks not only from common fish contaminants such as PCBs and mercury, but also from PFAS. More information can be found on DNR's fish advisory page

Follow healthy swimming practices. 

PFAS do not easily enter the body through the skin. Therefore, it is generally safe to swim in and use surface water bodies for recreational activities. To reduce the chance of accidental ingestion of PFAS, we recommend that you and your children:

Keep water out of your mouth. If surface water gets in your mouth, don't swallow it. Besides PFAS, surface water can contain algae, bacteria, viruses, decaying organic matter and other contaminants that, if swallowed, can pose a health risk to humans and pets.

Avoid foam. Avoiding foam is important for everyone and especially for young children and pets, who are more likely to accidentally swallow foam. Foam found in surface water can result from natural causes, pollution or a combination of the two. While natural foams can contain algae, bacteria, parasites and decaying organic matter, foams caused by pollution can contain environmental contaminants such as PFAS. 

Shower after swimming. Shower off after swimming or wading in surface water. Always wash hands with soap and clean water before preparing food and eating.

Rinse your pets too. Rinse pets with clean water after they swim in surface water. Don’t let them lick foam or algae off their fur.

Vacuum your home routinely.

Soil containing traces of PFAS can be tracked into the home from outside. In addition, dust can contain PFAS from common household products, like stain resistant carpeting or water repellent clothing. Vacuuming, preferably using a vacuum with a HEPA filter, reduces the overall amount of dirt and dust in a home.

Limit contact with consumer products containing PFAS.

These may include:

  • Some grease-resistant paper, fast food containers/wrappers, microwave popcorn bags, pizza boxes and candy wrappers;
  • Nonstick cookware;
  • Stain resistant coatings used on carpets, upholstery and other fabrics;
  • Water resistant clothing;
  • Cleaning products;
  • Personal care products (shampoo, dental floss) and cosmetics (nail polish, eye makeup); and
  • Paints, varnishes and sealants.

Recent federal efforts to remove PFAS from consumer products have reduced the likelihood of exposure in consumer products; however, some products may still contain them.

If you have questions or concerns about products you use in your home, contact the U.S. Consumer Product Safety Commission at 1-800-638-2772.

How can I learn more?

Last Revised: June 15, 2022

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