What are PFAS?
Per- and poly fluoroalkyl substances are human-made compounds that do not easily break down in the environment or human body. They are often made for products because of their nonstick, water repellent, and stain resistant properties. PFAS are also known as “forever chemicals,” as they do not break down naturally and last in the environment for a long time. Their production and manufacturing, as well as agricultural and consumer product use, results in PFAS in our environment.
Do they matter for health?
Research on the health effects of PFAS in humans is still ongoing. Drinking water contaminated with high levels of some types of PFAS could increase the risk for developing testicular and kidney cancer, thyroid disease, high cholesterol, high blood pressure, and a reduced immune response to vaccines. PFAS compounds have also been weakly linked with ADHD and other effects on the brain like visual motor impairment and poor executive function.
Currently, state and federal drinking water guidelines exist for only some PFAS. As of April 2024, the US Environmental Protection Agency (EPA) finalized a National Primary Drinking Water Regulation (NPDWR) establishing legally enforceable levels, called Maximum Contaminant Levels (MCLs), for six PFAS in drinking water. PFOA, PFOS, PFHxS, PFNA, and HFPO-DA as contaminants with individual MCLs, and PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS using a Hazard Index MCL to account for the combined and co-occurring levels of these PFAS in drinking water. EPA also finalized health-based, non-enforceable Maximum Contaminant Level Goals (MCLGs) for these PFAS. here are not yet guidelines for many PFAS. For more info, visit https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas.
Most people are exposed to PFAS by drinking contaminated water, but PFAS have also been found in homes and other indoor settings. North Americans spend as much as 90% of their time indoors, making this another important way that people come into contact with PFAS. PFAS have been found in indoor air and dust, which can enter the human body through inhalation, ingestion, or skin contact.
PFAS can be brought into homes through consumer products treated for water- or stain-resistance such as furniture, carpets and rugs, clothing, and cosmetics. Food packaging and non-stick cookware can also introduce PFAS into homes and foods. For more information see our consumer product safety report.
Dust acts as a collective measure of contaminants in indoor air and products. Therefore measuring PFAS in dust can provide an overall picture of the levels and types of PFAS present in homes or indoor settings. Research has found links between levels of PFAS in house dust and human blood.
Young children are particularly susceptible to PFAS in dust and carpets because they crawl on floors and put their hands or other objects into their mouths.
Both under-sink and whole-house water filters can be effective at removing PFAS from well water. If you already have an under-sink or whole-house water filter installed, check with the manufacturer if it is designed to remove PFAS. Most systems that use activated carbon or reverse osmosis will be effective for PFAS, but water softeners are not.
If you don’t already have a water filter that removes PFAS, we recommend installing and maintaining an under-sink filter for the faucets that you use for drinking and cooking. Under-sink filters are generally cheaper and easier to install and maintain than whole-house systems.
You can also buy bottled water for drinking and cooking. Read on for more information about filters.
Choose PFAS-free products that are not advertised as being non-stick, stain-repellent, or water-repellent.
If PFAS are found in your water, there are common water filters that do a good job of removing them (see our Filters Page). If the total PFAS concentration in your water is 200 ppt or less, we recommend using an under-sink, activated carbon block filter. These types of filters have been shown to work well for removing PFAS from private well water and treated tap water in real world tests. They have also been shown to be effective at levels above 200 ppt of total PFAS during lab tests, but they have not been tested as extensively for well water at higher levels.
If the sum of all PFAS in your water is above 200 ppt, we recommend using a reverse osmosis filter. Reverse osmosis filters have been tested in the lab and have been shown to successfully remove up to 5,600 ppt of total PFAS. Make sure to use a filter that is certified to remove PFAS by a trusted source like NSF International (NSF), the International Association of Plumbing and Mechanical Officials (IAMPO), or the Water Quality Association (WQA).