PFAS 101

Forever chemicals, briefly explained.

PFAS (per- and polyfluoroalkyl substances) are a family of synthetic chemicals used since the 1940s in nonstick coatings, water-repellent fabrics, food packaging, and firefighting foam. The carbon-fluorine bond that makes them useful also makes them nearly indestructible — hence “forever chemicals.”

A 2023 U.S. Geological Survey study estimated that about 45% of U.S. tap water contains at least one PFAS compound. Studies link PFAS exposure to immune system effects, developmental issues, and certain cancers — which is why the EPA now regulates PFOA and PFOS in drinking water at 4 parts per trillion.

What actually works

Activated carbon block filtration, properly engineered and independently tested, reduces PFOA and PFOS below detectable levels. The certification that matters is NSF/ANSI 53 — a finished-system performance standard where the filter must reduce PFOA/PFOS to below 20 parts per trillion in controlled testing.

The Headwater is certified to exactly that standard, with results that read non-detect. You can verify any NSF certification on NSF's public listing database — we encourage it. Trust, but verify. The dipper does both.