How to Remove PFAS from Drinking Water

Article Summary

Reverse osmosis, certain activated carbon filters and specialized anion-exchange resins can reduce PFAS in drinking water. Performance depends on the specific chemical and treatment system. Look for documented PFAS reduction claims for the exact model and replacement cartridge. Boiling does not remove PFAS. Start with your water report or a suitable laboratory test, then choose treatment for drinking and cooking water.

PFAS, PFOS and PFOA: What Is the Difference?

PFAS means per- and polyfluoroalkyl substances—a large group of manufactured chemicals. PFOS (perfluorooctane sulfonate) and PFOA (perfluorooctanoic acid) are two individual PFAS. GenX chemicals, including HFPO-DA, are another part of this group. A filter tested for PFOA and PFOS is not automatically proven to reduce every PFAS.

They are often called “forever chemicals” because many break down very slowly in the environment. That nickname does not mean every PFAS stays in the human body forever. EPA explains PFAS and exposure.

Which Water Filters Remove PFAS?

Compare these three treatment approaches. The technology name alone does not establish the performance of a particular household filter.

Does Reverse Osmosis Remove PFAS?

RO membranes can reduce PFAS in water. For a home drinking-water system, check the complete system’s documented PFAS claims, rather than assuming a membrane’s general rejection percentage applies to all PFAS.

Under-sink RO treats water at a dedicated drinking-water faucet and uses a reject-water line. Plan for cabinet space, installation and the specified filter and membrane changes.

Activated Carbon

Certain carbon filters adsorb PFAS onto the media. Results vary with the PFAS compound, carbon type, contact time, water chemistry and remaining capacity. Some shorter-chain PFAS are harder to capture.

Choose a filter with the relevant PFAS claim. A chlorine taste-and-odor claim alone is not evidence of PFAS reduction.

Specialized Anion Exchange

Specific anion-exchange resins can capture PFAS. These are specialized treatment media; an ordinary household water softener is not equivalent.

Have a water-treatment professional evaluate the resin, source water, capacity and replacement needs for the application.

EPA’s overview of PFAS treatment technologies explains why results differ. These methods separate PFAS from water; they do not necessarily destroy the chemicals.

How Do You Know Whether PFAS Are in Your Water?

On City Water?

Ask your utility for PFAS test results and check its current water-quality information. Confirm which PFAS were tested, the results and any local recommendations. A report without PFAS data does not establish that PFAS are absent.

Using a Private Well?

Contact your state health or environmental agency about local PFAS concerns and certified testing laboratories. Follow the lab’s sampling instructions and ask which PFAS its test measures and how low it can report results.

Taste, smell, water clarity and a TDS meter cannot identify PFAS. A laboratory “not detected” result means the substance was below that test’s reporting limit, not proof of absolute zero. See EPA’s practical steps for households.

How to Choose a PFAS Water Filter

Step 1: Match the exact model and cartridge
Read the certification listing or performance data sheet for the system you will buy. Similar-looking replacement cartridges may have different claims.
Step 2: Check which PFAS it reduces
Look for a specific PFAS reduction claim under NSF/ANSI 53 or NSF/ANSI 58. Certification to a standard for a different contaminant does not establish PFAS performance.
Step 3: Compare treated levels and capacity
Check the tested inlet and outlet concentrations, rated capacity, flow and operating conditions. A removal percentage by itself does not tell you the treated concentration.
Step 4: Plan for ongoing replacement
Follow the manufacturer’s replacement schedule and rated capacity. Do not wait for taste or odor to change before servicing a PFAS filter.

A Certification Logo Is Only the Starting Point

EPA’s 2024 public drinking-water rule sets separate limits of 4 parts per trillion for PFOA and 4 parts per trillion for PFOS. Do not assume a certified filter necessarily delivers water below those levels under your conditions. Compare the certification’s tested threshold and the manufacturer’s data.

Check the NSF drinking-water treatment listings and NSF’s PFAS filter guidance. For current regulatory details, use EPA’s PFAS drinking-water rule page.

Considering an Under-Sink RO System?

Microline under-sink reverse osmosis system with storage tank and drinking-water faucet

Compare complete systems, installation space and ongoing filter costs. Before choosing one for PFAS, confirm the exact model’s PFAS performance documentation. The system pictured illustrates an RO setup; it is not a PFAS certification claim.

Compare Under-Sink RO Systems

See what to check before buying RO · Ask our team about system selection

Does Boiling Water Remove PFAS?

No. Boiling does not remove PFAS or reduce PFAS exposure risk. Boiling for a microbial concern and treating dissolved chemicals are different tasks. Follow your utility or health department’s instructions if PFAS are found in your supply. Source: NSF.

Where Do PFAS in Drinking Water Come From?

PFAS can enter water near manufacturing sites, waste-disposal areas and locations where certain firefighting foams have been used. Some consumer products have also used PFAS for properties such as stain, grease or water resistance. The presence of a product category alone does not establish contamination in your water.

Illustrated examples of product categories that may contain or have historically used PFAS

Examples of potential PFAS uses; not every product in these categories contains PFAS. Your water report or appropriate testing is more useful than guessing from nearby products.

Why Are PFAS in Water a Health Concern?

Exposure to certain PFAS at certain levels has been linked to effects such as increased cholesterol, reduced immune response and an increased risk of some cancers. Risk depends on the chemical, exposure level and duration. Avoid treating every PFAS as having identical health effects. Read EPA’s current health overview.

Mother and daughter drinking glasses of water together

For many households, the practical starting point is water used for drinking and cooking. Discuss local results and exposure concerns with your utility, health department or healthcare professional.

Does a PFOS Filter Also Remove GenX?

Not necessarily. GenX chemicals are different PFAS, and a PFOS or PFOA reduction claim does not establish performance for HFPO-DA. Check whether the specific compound appears in the system’s test data. A replacement chemical should not automatically be described as safer.

PFAS Water Filter FAQs

Will a refrigerator filter remove PFAS?

Only if the exact filter has a relevant, documented PFAS reduction claim. Many refrigerator filters are intended for other concerns. Check the model’s listing and rated replacement capacity.

Do UV systems remove PFAS?

UV disinfection is used for microorganisms. Do not rely on a household UV disinfection chamber to reduce PFAS; it serves a different treatment purpose.

Do I need a whole-house PFAS filter?

Not every household needs the same approach. Point-of-use treatment addresses a connected drinking-water outlet. Whole-house treatment requires a separate assessment of water results, flow, media capacity and maintenance. Ask your local health agency for advice about your supply.

How often should a PFAS filter be replaced?

Use the manufacturer’s schedule and rated capacity for the exact cartridge and your application. Water use and source-water conditions matter. A filter that still tastes fine may have reached its treatment capacity.

Does filtration destroy forever chemicals?

Typical carbon and ion-exchange filters capture PFAS in their media, while RO separates them into a reject-water stream. Follow local and manufacturer guidance for spent cartridges and treatment waste.