PFAS Water Filters: How to Verify Reduction Claims

What PFAS are, briefly

PFAS (per- and polyfluoroalkyl substances) are a large group of manufactured chemicals used in many products. The EPA regulates certain PFAS in public drinking water and has required utilities to monitor for them under its Fifth Unregulated Contaminant Monitoring Rule (UCMR 5). Your utility's annual Water Quality Report (Consumer Confidence Report) and EPA's UCMR 5 data show whether PFAS were detected in your system. Start there before buying anything.

What the EPA says to look for

The EPA advises looking on product labels for certification under NSF/ANSI 53 or NSF/ANSI 58 for PFAS reduction, and checking the certifier's website to see whether the product covers the type of PFAS you are trying to reduce. EPA also cautions that certification standards as of April 2024 did not yet show reduction down to EPA's new drinking water levels, and that it is working with standard-setting bodies to update them. In plain terms: certification is the best available check, but read exactly what is certified.

How to check a listing, step by step

1. Find the full model number on the unit or cartridge, not just the brand or series name.
2. Search it in the NSF certified products database for drinking water treatment units, or the listing of another accredited certifier.
3. Confirm the standard (53 for filters, 58 for reverse osmosis).
4. Confirm the contaminant line: PFOA, PFOS, or "total PFAS" as the listing defines it.
5. Note the rated capacity in gallons and the replacement interval.
6. Make sure the cartridge you will buy as a replacement is the same listed model.

Red flags in PFAS marketing

• "Tested to NSF standards" without a listing you can look up.
• Certification for chlorine taste (NSF/ANSI 42) presented as if it covered PFAS.
• A certified cartridge sold in a housing or system that is not part of the listing.
• Percent-removal claims with no source.
• No stated capacity, so you cannot tell when it stops performing.

Where reverse osmosis fits

Reverse osmosis is a common point-of-use method listed under NSF/ANSI 58 for some PFAS. Not every RO model is certified for PFAS, so the listing check above still applies. Living Waters does not claim that any particular system removes PFAS; Jorge will show you how to check the model listing for any system you consider, including the ones he offers. See carbon vs reverse osmosis and whole-house filtration vs RO.

Maintenance is part of the claim

The EPA notes filters are only effective if maintained according to the manufacturer's instructions. A certified cartridge past its rated capacity is no longer performing as tested. Ask what the replacement schedule is and what it costs to own; see RO filter replacement costs.

Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist