PFAS in Drinking Water: The Forever Chemicals and How Filters Help
PFAS are persistent industrial chemicals showing up in tap water worldwide. What we know about the health risks, current limits, and which filters actually remove them.
Per- and polyfluoroalkyl substances, known as PFAS, are a family of roughly 10,000 industrial chemicals used since the 1940s in non-stick coatings, firefighting foam, packaging and textiles. They are extremely resistant to degradation and accumulate in soil, water and the human body, which is why they are often called forever chemicals.
Why are PFAS a concern?
Long-running studies link some PFAS subgroups to thyroid disease, raised cholesterol, reduced vaccine response in children and certain cancers. The science is strongest for legacy compounds such as PFOA and PFOS.
How do PFAS reach tap water?
- Discharges from industrial sites and landfills
- Sewage sludge applied as fertiliser
- Use of aqueous film-forming firefighting foam, common around airports and military bases
Regulatory limits
The EU Drinking Water Directive sets a combined limit of 0.1 micrograms per litre for 20 selected PFAS, effective from 2026. The US EPA finalised an MCL of 4 ng/L for PFOA and PFOS in 2024. Several states and countries enforce stricter values.
Which filters remove PFAS?
- Certified activated carbon block filters (NSF/ANSI 53 with explicit PFOA/PFOS reduction): effective for long-chain and many short-chain PFAS. Replace cartridges on schedule.
- Reverse osmosis: removes essentially all PFAS variants when properly maintained.
- Ion exchange resins: used mostly at utility scale.
Unbranded pitcher filters without certification are not enough.
What to do if you are concerned
Ask your utility for its latest PFAS test results or check the annual water quality report. If values are elevated, a private laboratory test typically costs around 80 to 150 euros.