Chemical / IngredientWater Filters

PFAS in Drinking Water: Which Filters Actually Remove Them?

An estimated 176 million Americans have PFAS in their tap water. Standard pitcher filters don't remove them — but reverse osmosis and certified carbon block filters do.

Renee · Founder, R3

What is PFAS (Per- and Polyfluoroalkyl Substances)?

PFAS (per- and polyfluoroalkyl substances) are a class of more than 10,000 synthetic chemicals built on an unbreakable carbon-fluorine bond. They don't degrade in soil, water, or the human body — earning the name "forever chemicals." PFAS are linked to cancer, immune suppression, thyroid disruption, and developmental harm. For a full overview of where PFAS appear across product categories, see our PFAS hub page.

How PFAS (Per- and Polyfluoroalkyl Substances) appears in Water Filters

PFAS enter drinking water primarily through three routes: military bases and airports where AFFF (aqueous film-forming foam) firefighting chemicals were used for decades and leached into groundwater; industrial discharge from manufacturers of fluorochemicals, electronics, and textiles; and wastewater treatment plants that concentrate PFAS from household products and industrial inputs without the ability to remove them.

Municipal water treatment was never designed to handle PFAS. Conventional treatment processes — chlorination, flocculation, sand filtration — do nothing to break the carbon-fluorine bond. PFAS pass straight through.

The EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR5), the most comprehensive national survey of tap water contaminants, detected PFAS in approximately 45% of US public water systems tested. An estimated 176 million Americans are drinking water with detectable PFAS.

In April 2024, the EPA finalized the first federal drinking water Maximum Contaminant Levels (MCLs) for PFAS: 4 parts per trillion (ppt) for PFOA and PFOS individually. The Maximum Contaminant Level Goal (MCLG) for both is zero — meaning the EPA has determined no level is safe. Compliance deadlines for water utilities extend to 2029, so most systems are currently operating above the new limits legally.

Communities near military bases are disproportionately affected. AFFF was used in routine fire training exercises for decades, saturating soil and groundwater. Some sites have measured PFOS in drinking water at levels 6 times the national average.

How to shop for Water Filters

Three filter technologies have demonstrated meaningful PFAS removal. Everything else — including the most popular pitcher filters on the market — falls short.

Reverse Osmosis (RO) — NSF/ANSI 58 The gold standard. RO forces water through a semipermeable membrane with pores small enough to block PFAS molecules. Certified RO systems remove 95-99% of both long-chain (PFOA, PFOS) and short-chain PFAS compounds. Available as under-sink systems ($150-$400) or countertop units ($300-$500). The tradeoff: RO produces wastewater (typically 3:1 ratio), removes beneficial minerals (remineralization filters solve this), and requires periodic membrane replacement.

Activated Carbon Block — NSF/ANSI 53 or P473 Carbon block filters use densely compressed activated carbon that adsorbs PFAS molecules as water passes through. Effective at 70-99% removal for long-chain PFAS (PFOA, PFOS, PFHxS). Less effective for short-chain PFAS compounds (PFBS, GenX), which are smaller molecules that slip through more easily. Available in pitcher, countertop, and under-sink formats. More affordable than RO and produces no wastewater.

Ion Exchange Resin — Emerging Technology Specialized anion exchange resins can capture PFAS at high efficiency, including some short-chain compounds that carbon misses. Primarily used in municipal treatment and whole-house systems. Consumer-grade products are limited but growing. Not yet widely NSF-certified for residential PFAS removal.

Why Standard Brita and PUR Pitchers Fail Most Brita and PUR pitchers use granulated activated carbon (GAC) — loose carbon granules that water flows around, not through. The contact time and surface area are insufficient for PFAS adsorption. GAC reduces chlorine taste and some sediment, but PFAS molecules pass through largely untouched. The critical difference is granulated vs. block: carbon block compresses the media into a solid structure that forces water through microscopic channels, dramatically increasing contact time and removal efficiency.

The NSF Certification Trap Many filters display the NSF logo, but the logo alone means nothing for PFAS. You need to verify the specific standard number: - NSF/ANSI 58 = reverse osmosis, tested for PFAS removal - NSF/ANSI 53 = carbon block, tested for specific contaminants (check that PFOA/PFOS are on the contaminant list) - NSF P473 = the protocol specifically designed for PFAS testing - NSF 42 = taste and odor only — does NOT address PFAS

Verify any filter's certification at nsf.org/certified-products-systems. Search by manufacturer and check which specific contaminants were tested.

PFAS (Per- and Polyfluoroalkyl Substances)-free Water Filters alternatives

Best Budget Option: Clearly Filtered Pitcher (~$90) The most affordable NSF P473-certified PFAS filter available. Independent testing shows 99.5%+ removal of PFOA and PFOS. Replacement filters run about $50 every 4 months for a family of four. The best entry point for most households.

Best Countertop: [AquaTru Countertop RO](/products/aquatru-classic-countertop-ro) (~$400) A countertop reverse osmosis system that requires no installation — plug in, fill the tank, press start. NSF/ANSI 58 certified. Removes 95-99% of PFAS including short-chain compounds that carbon filters miss. Produces less wastewater than traditional RO (4:1 vs. typical 3:1). Good for renters or anyone who can't modify plumbing.

Best Under-Sink: APEC RO Systems ($200-$350) APEC's under-sink reverse osmosis systems are NSF/ANSI 58 certified with dedicated PFAS testing documentation. Five-stage filtration with remineralization. Requires basic plumbing installation (dedicated faucet). The standard recommendation for households with pregnant women or infants near contaminated water sources — set it and forget it, with filter changes every 6-12 months.

For Whole-House Protection Whole-house carbon block systems from brands like Aquasana can reduce PFAS at every tap, including shower water. More expensive ($1,000-$2,000 installed) and less efficient than point-of-use RO, but eliminates the need for individual filters on every faucet. Best for families on well water in contaminated areas.

Frequently asked questions

Does Brita remove PFAS?

Standard Brita pitchers do not reliably remove PFAS. Most Brita models use granulated activated carbon (GAC), which reduces chlorine taste but lacks the contact time and surface density needed to adsorb PFAS molecules. Brita's Elite filter (formerly Longlast) uses a different media and claims some PFAS reduction, but it is not NSF P473 certified for PFAS. If PFAS removal is your goal, choose a filter specifically certified to NSF/ANSI 58, NSF/ANSI 53 with PFAS on the contaminant list, or NSF P473.

What is the cheapest water filter that removes PFAS?

The [Clearly Filtered pitcher](/products/clearly-filtered-water-pitcher) at approximately $90 is the most affordable NSF P473-certified option. It uses a proprietary carbon block technology (not granulated carbon) and independent lab tests show 99.5%+ removal of PFOA and PFOS. Replacement filters cost about $50 every 100 gallons. For a family of four, that works out to roughly $150 per year in filter costs after the initial purchase — significantly less than bottled water and far more effective.

Is bottled water PFAS-free?

Not necessarily. Consumer Reports tested 47 bottled water brands in 2020 and found detectable PFAS in several, including some that exceeded 1 ppt. Bottled water is regulated by the FDA, not the EPA, and the FDA has not yet set PFAS limits for bottled water. Some brands (like Fiji and Voss) have tested below detection limits, but there is no guarantee across the category. A certified home filter gives you more control and verification than relying on bottled water labels.

How do I know if my tap water has PFAS?

Start with the EPA's UCMR5 data, which tested public water systems serving populations of 3,300 or more between 2023 and 2025. Results are available on the EPA's website. If your utility was tested, you can see exactly which PFAS were detected and at what levels. For private wells, UCMR5 does not apply — you will need to order a home water test. Tap Score by SimpleWater offers a PFAS-specific test kit for around $200 that covers 30+ PFAS compounds with lab analysis. Your state environmental agency may also offer free or subsidized testing if you live near a known contamination site.

What does NSF/ANSI 58 mean?

NSF/ANSI 58 is the certification standard for reverse osmosis (RO) water treatment systems. It verifies that the system reduces specific contaminants — including PFAS — to levels at or below EPA health standards under controlled testing conditions. A filter certified to NSF 58 has been independently tested by NSF International (a third-party organization, not a government agency) and proven to perform as claimed. It is the most rigorous residential water filter certification for PFAS removal. You can verify any product's certification at nsf.org/certified-products-systems.

Do refrigerator water filters remove PFAS?

Most built-in refrigerator filters use granulated activated carbon and are certified only to NSF 42 (taste and odor). They do not remove PFAS. A small number of aftermarket fridge filters claim PFAS reduction, but very few carry NSF 53 or P473 certification for PFAS specifically. If your primary drinking water source is your refrigerator dispenser, the most practical solution is to fill the fridge reservoir with water that has already passed through a certified countertop or under-sink filter.