What Are PFAS (Per- and Polyfluoroalkyl Substances)?

PFAS have received enormous media attention in recent years, and for good reason. These toxic contaminants have been detected in drinking water systems across the entire country, in the blood of nearly every American, and in ecosystems far from any obvious source of pollution.

In this article, we'll explain what PFAS actually are, where they come from, how they affect your health, and where federal regulation stands as of February 2026.

Quick Summary

• What are PFAS?: Man-made "forever chemicals" that don't break down in the environment or your body.
• Where are PFAS found? Nonstick cookware, stain-resistant fabrics, food packaging, and firefighting foam.
• How do they get in drinking water? Industrial runoff and firefighting foam.
• PFAS present many health risks: Cancer, immune suppression, hormonal disruption, and developmental issues.
• PFAS regulations are limited: The EPA set limits for 6 PFAS in 2024, but rollbacks are already underway.
• How can I avoid PFAS? Get a filter certified to NSF/ANSI Standard 53 or 58 for PFAS.

What Are Per- and Polyfluoroalkyl Substances (PFAS)?

Per- and polyfluoroalkyl substances (PFAS) are a large category of man-made chemicals (nearly 15,000 individual substances recognized by the EPA) that share chemically stable carbon-fluorine bonds. This bond is one of the strongest in chemistry, which is what makes PFAS so durable, and so dangerous. PFAS do not readily break down in the environment or in the human body. This is why they're commonly called "forever chemicals."

PFAS are sometimes described as "emerging contaminants," meaning they've been detected in the environment but the full scope of risk to human health is still being studied.

GenX, PFOA, and PFOS are among the most commonly discussed individual PFAS. Chemical manufacturing companies including DuPont, Chemours, and 3M have been using variations of these chemicals in industrial and consumer products since the early 1950s.

PFAS are found in a wide range of everyday products and processes, including:

• Nonstick cookware (e.g., Teflon)
• Stain- and water-resistant fabrics and carpets (e.g., Scotchgard)
• Waterproof clothing
• Long-lasting cosmetics, such as mascara
• Certain food packaging, like microwave popcorn bags and fast-food wrappers
• Specialty firefighting foams (Aqueous Film Forming Foam / AFFF) commonly used at airports, military bases, and chemical plants
• Metal plating and industrial processes
  

While some of these products and processes can be avoided, others cannot. This is why regulation and filtration are so important when it comes to PFAS.

Are PFAS Regulated?

Yes, but the regulatory picture is complicated and still evolving.

In April 2024, the EPA finalized the first-ever enforceable nationwide drinking water standards for six individual PFAS: PFOA, PFOS, PFHxS, PFNA, HFPO-DA (GenX), and PFBS (as part of a mixture). Prior to this, in 2016, the EPA had set a non-enforceable Lifetime Health Advisory Level of 70 parts per trillion for PFOA and PFOS combined, which municipalities were not legally required to follow. 

However, since the 2024 rule was published, the EPA has asked courts to roll back portions of it. Under the proposed changes, the number of regulated PFAS would be reduced from six to just two (PFOA and PFOS), the mixture assessment framework would be eliminated, and the municipal compliance deadline would be extended to 2031.

Even if the federal rule stands fully intact, it covers only six of the nearly 15,000 PFAS recognized by the EPA. Meaningful protection from the tap is years away for most Americans.

What Are the Health Effects of PFAS?

The health risks of PFAS exposure are serious and well-documented.

According to research from the Agency for Toxic Substances and Disease Registry (ATSDR) and numerous peer-reviewed studies, PFAS exposure is associated with:

• Cancer, including kidney and testicular cancer
• Immune system suppression, including a decreased ability to respond to vaccines
• Hormonal disruption, including thyroid dysfunction and elevated cholesterol levels
• Developmental issues in infants and young children, including low birth weight and preterm birth
• Increased risk of miscarriage
• Lowered fertility rates
  

While research is ongoing, our understandings about the impact of PFAS on our health paint a clear picture. We should avoid PFAS exposure if at all possible.

How Are We Exposed to PFAS?

People are exposed to PFAS through several routes, including:

• Drinking water that has been contaminated by the byproducts of firefighting foams or industrial runoff
  
• Using consumer products that contain PFAS, most commonly cookware, clothing, cosmetics, and food packaging
• Eating fish or shellfish exposed to contaminated water, where PFAS accumulate through the food chain
  
• Occupational exposure for workers who manufacture or regularly use PFAS-containing products

PFAS contamination is especially prevalent near military bases, airports, and industrial facilities where firefighting foam has been deployed or where PFAS-containing wastewater has been discharged.

Because PFAS are so persistent, once a groundwater supply is contaminated, it stays contaminated, and that contamination can migrate far from its original source. Private well owners face particular risk, as the EPA does not monitor private wells.

Do Water Filters Reduce PFAS?

Not all of them. And the difference matters significantly.

A study by Duke University and NC State University tested a wide range of water filter brands for their ability to remove PFAS. Several major brands performed poorly. Some, including Brita, Berkey, Aquasana, Samsung, and GE, even added PFAS back into the water, likely due to low-quality or over-saturated filter media.

Meanwhile, Hydroviv's Under Sink Filter and Fridge/Ice Maker Filter performed very well, reducing PFAS to undetectable levels throughout each filter's 6-month lifespan.

To ensure your filter is actually protecting you, look for these certifications:

Want to learn more about filtering PFAS from your home's water? Hydroviv's Water Experts are available to answer more questions through live chat.