What Are PFAS or “Forever Chemicals”?

Official sources: U.S. Environmental Protection Agency (EPA) | Agency for Toxic Substances and Disease Registry (ATSDR/CDC) | National Institute of Environmental Health Sciences (NIEHS) | U.S. Food and Drug Administration (FDA)

Regulatory and litigation status reviewed: August 2026

What are PFAS?

PFAS stands for per- and polyfluoroalkyl substances.

PFAS are not one chemical. They are a large family of synthetic chemicals that have been used in commercial, industrial, and consumer applications for decades.

PFAS have been useful because many resist:

• Water
• Oil
• Grease
• Heat
• Stains
• Chemical breakdown

Those same properties can also make some PFAS very persistent after they enter the environment.

EPA notes that there are thousands of PFAS chemicals and that different PFAS can behave differently in people and the environment. (US EPA)

Why are PFAS called “forever chemicals”?

PFAS are often called forever chemicals because many of them break down very slowly.

The strong carbon-fluorine bonds found in PFAS molecules can make certain compounds resistant to natural degradation.

As a result, some PFAS can:

• Remain in soil and water for long periods.
• Travel through groundwater.
• Build up in people or animals.
• Persist after the original source of contamination is gone.

Not every PFAS behaves identically, and scientists caution against treating the entire chemical family as though every compound has the same persistence, toxicity, or health effects.

What are PFOA and PFOS?

Two of the best-studied PFAS are:

PFOA

Perfluorooctanoic acid (PFOA) was historically used in manufacturing and in applications involving water-, stain-, and grease-resistant materials.

PFOS

Perfluorooctane sulfonic acid (PFOS) was historically used in products including certain firefighting foams and stain-resistant materials.

PFOA and PFOS have been phased out of many U.S. manufacturing uses, but they remain important environmental contaminants because of their persistence and historical use.

They are also the two PFAS currently subject to individual nationwide federal drinking-water limits of 4.0 parts per trillion under EPA's 2024 drinking-water rule. (US EPA)

Where are PFAS found?

PFAS have been used in many types of products and industrial processes.

Examples can include:

• Firefighting foam
• Stain-resistant textiles
• Water-resistant clothing
• Grease-resistant food packaging
• Certain cosmetics
• Industrial coatings
• Wire insulation
• Cleaning products
• Some manufacturing processes

FDA also notes that PFAS can enter food through environmental contamination, crops or animals raised in contaminated areas, food processing, or certain materials that contact food. (U.S. Food and Drug Administration)

Not every product in these categories contains PFAS.

How are people exposed to PFAS?

PFAS exposure can occur through several routes.

Drinking water

Contaminated groundwater or surface water can carry PFAS into public or private drinking-water supplies.

Food

PFAS may enter food from contaminated soil, water, animals, processing, or food-contact materials.

Work

Certain occupations may involve higher exposure, including:

• Firefighting
• Chemical manufacturing
• Some industrial jobs
• Work involving PFAS-containing materials

Consumer products

Some products may contribute to exposure depending on the PFAS used and how the product is handled.

EPA notes that people can be exposed through contaminated drinking water, food, consumer products, and occupational settings. (US EPA)

Can PFAS build up in the human body?

Some PFAS can remain in the body for years.

The length of time varies by chemical.

This means repeated exposure to some PFAS can cause blood levels to build up over time.

Other PFAS leave the body more quickly.

Because PFAS are a large and diverse chemical family, scientists increasingly evaluate individual compounds rather than assuming every PFAS behaves the same way.

What health effects are associated with PFAS exposure?

The strongest human evidence is concentrated around a relatively small number of well-studied PFAS.

ATSDR's July 2026 clinical guidance identifies evidence of associations involving several health outcomes. (ATSDR)

These include:

• Increased cholesterol levels
• Small decreases in infant birth weight
• Lower antibody response to some vaccines in children
• Kidney cancer
• Testicular cancer
• Pregnancy-induced hypertension or preeclampsia
• Changes in liver enzymes

The strength of evidence differs by condition and by the specific PFAS involved.

For example, ATSDR identifies evidence connecting PFOA with kidney and testicular cancer, while evidence involving other PFAS and cancer is less established. (ATSDR)

Does PFAS exposure cause cancer?

Some PFAS exposures have been associated with certain cancers, but it is inaccurate to say that all PFAS cause cancer.

ATSDR's current review identifies an association between PFOA exposure and kidney and testicular cancer. It also notes that causal relationships have not been established for every health outcome associated with PFAS exposure. (ATSDR)

Cancer risk can depend on:

• The particular PFAS
• Exposure level
• Exposure duration
• Route of exposure
• Age
• Individual health factors
• Other environmental or occupational exposures

The presence of PFAS in someone's blood does not mean that person will develop cancer.

What does “association” mean?

This is an important distinction.

An association means researchers observe that an exposure and a health outcome occur together more frequently than expected.

That does not automatically prove that the exposure caused the outcome.

Scientists consider additional factors including:

• Consistency across studies
• Exposure levels
• Biological mechanisms
• Study quality
• Alternative explanations
• Dose-response relationships

ATSDR specifically cautions that evidence of association does not necessarily establish causation. (ATSDR)

Are all PFAS equally dangerous?

No.

PFAS includes thousands of different chemicals.

They can differ in:

• Chemical structure
• Persistence
• Ability to build up in the body
• Toxicity
• Uses
• Environmental behavior

PFOA and PFOS are among the most extensively studied PFAS.

There is far less health information about many newer or less commonly studied compounds.

EPA says this diversity is one reason evaluating PFAS health and environmental risks is difficult. (US EPA)

What does EPA currently regulate in drinking water?

EPA established the first nationwide enforceable drinking-water standards for PFAS in April 2024.

That rule included individual Maximum Contaminant Levels for:

• PFOA
• PFOS
• PFHxS
• PFNA
• HFPO-DA, commonly called GenX

It also established a Hazard Index for certain mixtures involving PFHxS, PFNA, GenX, and PFBS. (US EPA)

However, the regulatory landscape is now changing.

What is the current federal drinking-water limit for PFOA and PFOS?

EPA's enforceable Maximum Contaminant Level for both PFOA and PFOS is 4.0 parts per trillion (ppt). (US EPA)

Those federal standards remain in place as of August 2026.

EPA announced in May 2026 that it intends to keep the PFOA and PFOS limits, while proposing to let qualifying public water systems request additional time—potentially until 2031—to comply. (US EPA)

The proposal would not increase the 4 ppt limits themselves.

Is EPA changing the PFAS drinking-water rule?

Yes, but the changes are still proposed, not final.

On May 18, 2026, EPA announced two proposed regulatory actions.

PFOA and PFOS

EPA proposed maintaining the existing 4 ppt standards while allowing qualifying water systems additional time, potentially through 2031, to meet them. (US EPA)

Four other PFAS regulatory provisions

EPA separately proposed rescinding federal drinking-water regulations for:

• PFHxS
• PFNA
• HFPO-DA / GenX
• The Hazard Index mixture involving these substances and PFBS

EPA says the proposed rescission is based on how the 2024 regulations were adopted under the Safe Drinking Water Act—not on a finding that those chemicals pose no health concern. (US EPA)

The public comment periods for both proposed rules closed on July 20, 2026.

As of August 2026, these remain proposed regulatory changes.

Does that mean PFHxS, PFNA, GenX, and PFBS are now unregulated?

Not yet under the federal drinking-water rule.

The 2024 federal rule remains the underlying regulation while EPA proceeds through its rulemaking process.

EPA has proposed rescinding those particular regulatory determinations and associated drinking-water provisions, but the proposal has not yet become a final rule as of this review. (US EPA)

States may also maintain separate PFAS standards or requirements.

What should I do if PFAS are found in my drinking water?

The appropriate response depends on:

• Which PFAS were detected
• Concentration
• Whether the water comes from a public system or private well
• State and local requirements

For public water systems, consumers can review water-quality information and contact the utility for current testing and treatment information.

EPA also provides consumer information about certified treatment options that may reduce PFAS in household drinking water.

People using private wells may need to arrange independent testing depending on local conditions and state guidance.

Can boiling water remove PFAS?

No.

Boiling water is not a reliable method for removing PFAS.

Because water evaporates while PFAS may remain, boiling can potentially increase the concentration of PFAS in the remaining water.

PFAS reduction generally requires appropriate treatment technology rather than ordinary boiling.

EPA identifies treatment approaches such as:

• Granular activated carbon
• Ion exchange resins
• High-pressure membrane systems such as reverse osmosis

The appropriate system depends on the PFAS, concentration, water chemistry, and treatment setting.

Can PFAS be removed from drinking water?

Yes, certain technologies can substantially reduce many PFAS.

Common treatment approaches include:

Granular activated carbon

PFAS can bind to carbon media as water passes through.

Ion exchange

Special resins can capture PFAS from water.

Reverse osmosis

Membranes can remove many PFAS along with other contaminants.

No treatment system removes every PFAS equally well.

Filters also require proper maintenance and replacement.

Can I get tested for PFAS exposure?

PFAS blood testing exists, but interpreting the results can be difficult.

A blood test can show the amount of certain PFAS currently present in the blood.

It generally cannot tell:

• Exactly where exposure occurred
• Whether the PFAS caused a health condition
• Whether the person will develop a future disease
• What treatment is needed based only on the number

ATSDR recommends that clinicians consider exposure history, individual health factors, and current evidence when discussing PFAS with patients. (ATSDR)

Is there a medical treatment that removes PFAS from the body?

There is no standard medical treatment approved specifically to remove PFAS from the body.

For most people, blood concentrations of a PFAS decline gradually after exposure stops, although some compounds remain in the body for years.

The practical focus is usually:

• Identify and reduce ongoing exposure.
• Follow routine preventive care.
• Address individual health risks and conditions.
• Discuss unusually high or occupational exposure with a healthcare professional.

What is the connection between PFAS and AFFF firefighting foam?

Certain aqueous film-forming foams (AFFF) historically contained PFAS or compounds that could break down into PFAS.

AFFF was widely used to control highly flammable liquid-fuel fires at locations such as:

• Airports
• Military bases
• Fire-training facilities
• Industrial sites

Repeated AFFF use has contributed to PFAS contamination of soil and groundwater at some sites.

This history is the basis of the large federal AFFF/PFAS litigation known as MDL No. 2873. (US Courts SDCA)

Is PFAS litigation the same as the AFFF lawsuit?

Not exactly.

PFAS litigation is a broad category.

It can include claims involving:

• Drinking-water contamination
• Firefighting foam
• Personal injury
• Property damage
• Environmental cleanup
• Industrial contamination
• Public water systems

AFFF litigation is a major subset of PFAS litigation focused on firefighting foam.

The federal AFFF MDL involves claims alleging that PFAS-containing AFFF contaminated groundwater near military bases, airports, and industrial sites and caused personal injury, medical-monitoring needs, property damage, or economic losses. (US Courts SDCA)

Is there a PFAS MDL?

The main federal PFAS products-liability proceeding is:

In re: Aqueous Film-Forming Foams Products Liability Litigation

MDL No. 2873

U.S. District Court for the District of South Carolina

The court explains that the proceeding has involved more than 10,000 associated cases and tens of thousands of plaintiffs involving varied PFAS-related claims. (US Courts SDCA)

However, not every PFAS dispute in the United States is part of MDL 2873.

Other PFAS matters may proceed separately depending on the product, defendant, contamination source, and legal claim.

What kinds of claims are in MDL 2873?

The federal court identifies several broad types of claims:

• Personal injury
• Medical monitoring
• Property damage
• Economic loss

Many claims involve allegations that PFAS-containing firefighting foam contaminated groundwater.

Plaintiffs include individuals as well as public water systems and other entities. (US Courts SDCA)

Those different types of plaintiffs can have very different legal claims and settlement structures.

Have PFAS lawsuits settled?

Some major PFAS contamination claims have settled, particularly claims involving public drinking-water systems.

But there is no single settlement resolving every PFAS claim in the United States.

The broader litigation continues.

Individual personal-injury claims, municipal claims, environmental cases, and other PFAS disputes should not be treated as one uniform lawsuit.

A settlement involving a water utility does not automatically determine what an individual personal-injury claimant may receive.

Are public-water PFAS settlements the same as personal-injury settlements?

No.

This distinction is essential.

Public-water-system claims

These generally seek compensation for costs such as:

• Testing
• Treatment
• Filtration
• Remediation
• Infrastructure

Personal-injury claims

These involve allegations that PFAS exposure caused a particular person's illness.

Personal-injury claims require individual evidence involving exposure, diagnosis, causation, and damages.

Money paid to a water system to install treatment equipment is not a personal-injury award for residents of that community.

Who may have a PFAS personal-injury claim?

Potential personal-injury claims may involve people who allege substantial PFAS exposure followed by a serious condition associated with the particular PFAS involved.

Relevant factors can include:

• Exposure source
• Specific PFAS
• Concentration
• Duration
• Occupation
• Drinking-water history
• Residence history
• Medical diagnosis
• Other possible causes
• Applicable state law
• Filing deadlines

The presence of PFAS in someone's blood or drinking water does not automatically establish a legal claim.

What evidence may matter in a PFAS claim?

Potential evidence can include:

Exposure evidence

• Drinking-water testing
• Environmental sampling
• Employment records
• Military records
• Firefighting records
• Residence history
• Worksite records
• Historical contamination data

Medical evidence

• Diagnosis records
• Pathology reports
• Oncology records
• Treatment records
• Medical history
• Other potential risk factors

Product or source evidence

• AFFF records
• Industrial discharge information
• Product records
• Procurement records
• Environmental investigations

PFAS exposure can involve multiple sources, making source identification especially important.

Can Veterans be exposed to PFAS?

Yes.

PFAS contamination has been identified at a number of military installations, often associated with historical use of AFFF for fuel-fire suppression and firefighting training.

A Veteran alleging PFAS-related illness may potentially encounter separate legal or benefit questions involving:

• Product-liability litigation
• VA disability compensation
• Environmental exposure records

A product-liability claim and a VA disability claim are separate processes.

Are PFAS banned in the United States?

No.

There is no blanket federal ban on the entire PFAS chemical family.

Federal regulation instead addresses particular PFAS, uses, releases, drinking-water contamination, reporting, and environmental cleanup through several different laws.

Because PFAS includes thousands of chemicals and applications, regulation is evolving compound by compound and use by use.

Are PFOA and PFOS still manufactured in the United States?

Major U.S. manufacturers largely phased out production and use of PFOA and PFOS years ago.

However, historical contamination remains because these chemicals can persist for long periods.

They may also still enter the United States through certain imported products or arise from older materials and environmental reservoirs.

The fact that domestic manufacturing declined does not make historic contamination disappear.

What is EPA doing about PFAS waste and disposal?

PFAS disposal is another evolving area.

EPA issued updated interim guidance in April 2026 addressing destruction and disposal of PFAS-containing materials.

The guidance discusses currently available approaches including:

• Underground injection
• Landfills
• Thermal treatment under certain conditions

EPA also identifies significant research gaps and emphasizes that PFAS disposal technologies require continued study. (US EPA)

There is no single disposal method that is appropriate for every PFAS-containing waste stream.

Are PFAS in food regulated?

FDA monitors PFAS in the U.S. food supply and evaluates potential exposure from both environmental contamination and food-contact materials.

FDA's July 2026 PFAS resource notes that PFAS can enter food through contaminated soil, water, animals, processing, and certain cookware or food-contact applications. (U.S. Food and Drug Administration)

Regulatory actions involving PFAS in food packaging and other applications have evolved over time.

PFAS in food is a separate issue from EPA's drinking-water standards.

Common misconceptions

Myth: PFAS are one chemical, and every PFAS has been proven to cause cancer.

Reality: PFAS are a large family containing thousands of chemicals with different properties and different amounts of health research. Current evidence is strongest for certain compounds such as PFOA and PFOS. ATSDR identifies associations between some PFAS exposures and specific health outcomes, but it also states that causal relationships have not been established for every effect or every PFAS. (ATSDR)

Why this matters

PFAS is a difficult topic because the label “forever chemicals” can make thousands of different substances sound like one uniform hazard.

They are not.

The strongest public-health evidence involves a relatively small group of PFAS that have been studied for years, particularly PFOA and PFOS.

At the same time, PFAS contamination is a real and widespread environmental issue. EPA has established extremely low federal drinking-water limits for PFOA and PFOS, ATSDR identifies multiple health outcomes associated with certain PFAS exposures, and federal litigation involving PFAS contamination now includes thousands of cases.

The most useful questions are therefore specific:

Which PFAS? At what concentration? Where did the exposure occur? For how long? What does the medical evidence show? And what regulatory or legal framework applies?

That is much more informative than simply asking whether “PFAS are dangerous.”