Yes, carbon can take PFAS out of water, but how well it works depends on the filter and the type of PFAS. BOROUX filters are lab-tested for PFAS through 400 gallons. View the full, published lab test report so you can see exactly what it shows.
What a real test looks like
If you’re going to trust a filter with your family’s water, it helps to know what a good test actually looks like. One Foundation Filter was tested by IAPMO R&T Lab in New Jersey, an independent lab accredited to ISO/IEC 17025, using an R&D test to the NSF/ANSI 53 PFAS protocol (53 is the standard for filters that reduce health-related contaminants). The full report is readily available so you can check the numbers. The lab spiked the water with about 2 µg/L (micrograms per liter) of total PFAS, ran it through the filter 10 gallons at a time, and then sampled what came out six times through 400 gallons. Every total PFAS sample stayed at or below the test's 0.02 µg/L limit.
The table gives the full series compound by compound, with what went in, what came out at each of the sample points, and the limit the test set.
| Compound | Challenge level (µg/L) | Effluent, six samples to 400 gal (µg/L) | Pass limit (µg/L) |
|---|---|---|---|
| PFOA | 0.51, 0.52, 0.49, 0.52, 0.50, 0.50 | <0.01, 0.01, <0.01, <0.01, <0.01, 0.01 | — |
| PFOS | 0.98, 1.10, 1.00, 1.10, 1.10, 1.10 | <0.01, <0.01, 0.01, 0.01, <0.01, 0.01 | — |
| PFOA + PFOS | 1.49, 1.62, 1.49, 1.62, 1.60, 1.60 | <0.01, 0.01, 0.01, 0.01, <0.01, 0.02 | 0.02 |
| PFNA | 0.05, 0.05, 0.05, 0.05, 0.05, 0.05 | <0.001, 0.001, <0.001, <0.001, <0.001, <0.001 | 0.006 |
| PFHxS | 0.31, 0.29, 0.28, 0.30, 0.31, 0.29 | <0.01, <0.01, <0.01, <0.01, <0.01, <0.01 | 0.02 |
| PFHpA | 0.04, 0.04, 0.04, 0.04, 0.04, 0.04 | <0.01, <0.01, <0.01, <0.01, <0.01, <0.01 | 0.02 |
| Total PFAS | 2.15, 2.28, 2.14, 2.30, 2.26, 2.27 | <0.01, 0.011, 0.01, 0.01, <0.01, 0.02 | 0.02 |
| PFBS | 0.25–0.28 influent only | no result reported | — |
| PFDA | 0.01 influent only | no result reported | — |
0.01 µg/L = 10 ppt, or 10 parts per trillion. A dash means the report does not state an individual pass limit.
IAPMO R&T Lab (NJ) report #23-199-2-PFAS (Jan 24, 2024), R&D test to the NSF/ANSI 53-2022 PFAS protocol, as published in our Substance Reduction Test Report v2.0 (Oct 2025).
So does a BOROUX filter handle PFAS? In this test, yes, and the takeaway for your own shopping is to look for results by compound and by gallons rather than one big percentage. A single “removes 99% of PFAS” figure can hide a lot: which PFAS were tested, how much was in the water to start, and whether the filter was still performing near the end of its tested life or only when it was brand new. Results listed compound by compound, and sampled across the gallons, answer all three.
So what is carbon actually doing to PFAS?
How carbon removes PFAS, and where it struggles
Carbon does not break PFAS down; it catches them on its surface, a bit like lint sticking to a sweater.
Activated carbon is a maze of tiny passages with an enormous amount of surface area. PFAS molecules stick to those surfaces in a process called adsorption, with a D. The PFAS stays on the outside of the carbon rather than soaking in. The longer water stays in contact with the carbon, and the fresher the filter, the better the catch. That’s why contact time and capacity matter.
How well carbon works also depends on the molecule. PFAS have a carbon backbone called a chain, and longer-chain PFAS like PFOA and PFOS are easier for carbon to catch, while shorter ones such as PFBS slip through more often. EPA’s researchers describe carbon as potentially 100 percent effective for a period of time, depending on the type of carbon, the depth of the carbon bed, the flow rate, the temperature and what else is in the water.
In real homes the results spread out more. A 2020 Duke and NC State study of 76 point-of-use filters in North Carolina homes found activated-carbon filters averaged 73% PFAS removal, with some removing the chemicals completely and others not reducing them at all, while under-sink reverse osmosis and two-stage filters hit 94% or more. That was one state and the filters weren’t named, but the spread is exactly why filter type matters, and why the table below sorts by type.
| Filter type | Reduces PFAS? | Depends on the filter? | Notes |
|---|---|---|---|
| Granular activated carbon (GAC) | Some products do | Yes: check for an NSF/ANSI 53 listing with a PFOA/PFOS or total-PFAS claim | Best on long-chain PFAS; short-chain adsorbs less |
| Carbon block | Some products do | Yes: same 53 check | Same chain-length limit |
| Pitcher carbon filters | Some products do | Yes: same 53 check | Duke field study included pitchers; results varied widely |
| Reverse osmosis | Typically yes, including short-chain | Yes: check for an NSF/ANSI 58 PFAS claim | ≥94% for under-sink units in the field study; membranes typically >90% |
| Ion exchange resin | Some products do | Yes: check for a 53 PFAS claim | EPA lists it as an effective type |
| BOROUX Foundation | Reduced in lab testing: total PFAS ~2.2 → ≤0.02 µg/L through 400 gal per filter | IAPMO R&T test report, R&D test to the NSF/ANSI 53 PFAS protocol | Results by compound in the first table |
EPA’s home-filter guidance (updated August 2026) says certifications as of April 2024 do not yet show that a filter will reduce PFAS to the limits EPA has now set. So the practical move is to check a filter’s listing or test report for PFAS by name rather than assuming any carbon filter covers it.
What PFAS are and how they get into tap water
PFAS stands for per- and polyfluoroalkyl substances. It is a family of thousands of manufactured chemicals, used since the 1940s. PFOA and PFOS are two of the most widely used and studied, and many US uses have since swapped them for other PFAS.
You know some of the uses: nonstick cookware, water-repellent fabric, food packaging, firefighting foam, personal care products and many industrial processes. They are often called forever chemicals because they persist in the environment. They reach water through manufacturing discharge, disposal, landfills, firefighting foam, and biosolids spread on fields.
A USGS tap water study estimated that at least 45% of US tap water has one or more types of PFAS, based on samples from 716 locations between 2016 and 2021. The most frequently detected were PFBS, PFHxS and PFOA.
That does not mean every home has a problem, only that checking your water is the sensible first step. Before you do, it’s fair to ask what health agencies say about exposure.
What exposure is linked to, according to EPA
EPA’s current health pages are careful with language, and it is worth reading them that way. Current peer-reviewed studies have shown that exposure to certain levels of PFAS may lead to:
- reproductive effects such as decreased fertility or increased high blood pressure in pregnant women;
- developmental effects or delays in children, including low birth weight, accelerated puberty, bone variations, or behavioral changes;
- increased risk of some cancers, including prostate, kidney, and testicular cancers;
- reduced ability of the immune system to fight infections, including reduced vaccine response;
- interference with the body’s natural hormones;
- increased cholesterol levels and/or risk of obesity.
That is EPA’s list, in EPA’s wording: “certain levels” and “may lead to.” It is not a diagnosis, and it says nothing about any particular filter. The practical takeaway is to find out what is actually in your own water rather than guess.
Where the law stands
Concerns like these are why the legal limits get so much attention. As of September 30, 2026, the federal drinking-water limits for PFOA and PFOS remain 4.0 ppt each, with compliance due in 2029. EPA has proposed a compliance extension that would give water systems granted an exemption until April 2031, and has separately proposed to rescind the four other 2024 limits: PFHxS, PFNA, HFPO-DA and the hazard index. Both are proposals, not final rules, and their comment periods closed July 20, 2026. A D.C. Circuit challenge was argued on September 18, 2026, and no decision had been reported as of this update.
Because the rules are still moving, the most practical thing you can do is look at your own water.
How to find out if your water has PFAS
Start with your utility’s annual drinking water quality report. If you are on a private well, the only way to know is a test from a certified laboratory.
For public systems, EPA’s Unregulated Contaminant Monitoring Rule 5 (UCMR 5) Data Finder can show whether your utility sampled for PFAS. EPA’s home filter guidance is blunt: if PFAS have not been measured in your water, or if they are below federal limits, a filter may not be useful. So it’s worth checking before you buy. For a step-by-step version, see how to know what’s in your tap water.
If the results say a filter makes sense, the next practical question is how long one lasts.
When to replace the filter
Every filter has a limit: when it is saturated with contaminants, it stops working as well. EPA’s guidance says replacing on the manufacturer’s schedule matters. Our PFAS testing followed one filter to 400 gallons, and since a BOROUX system uses two, the BOROUX Foundation filter life span guide lists 800 gallons per pair. The tested water used about 2 µg/L of PFAS, which is a significantly higher concentration than what is typically found in tap water. Testing your source water tells you how your own PFAS levels compare with the test.
A calendar reminder when you install it is an easy way to stay on schedule. For details, see how long BOROUX Foundation Filters last.
Next step
If you have checked your water and carbon fits your situation, the filter behind the data above is our BOROUX Foundation Filter.
