How long do PFAS stay in your body?

PFAS compounds have extremely long half-lives in the human body, meaning they take years to be eliminated even after exposure stops. The most studied PFAS compound, PFOS, has an estimated half-life of 4 to 5 years in human blood serum. PFOA has a half-life of approximately 3.5 years. This means that even after 4 years without any new exposure, only half of the accumulated PFAS would be eliminated.

Because most people have continuous daily exposure from multiple sources including clothing, food packaging, water, and home textiles, the body burden of PFAS tends to increase over a lifetime rather than decrease. Blood testing studies have found detectable PFAS in over 97% of Americans tested. Higher concentrations have been correlated with increased risks of certain cancers, thyroid disease, immune suppression, and reproductive issues.

While you cannot control all sources of PFAS exposure, reducing contact with PFAS-treated clothing is one of the most actionable steps. Given that clothing sits against your skin for hours each day and that sweat increases dermal absorption, choosing PFAS-free garments can meaningfully slow the accumulation of these persistent chemicals in your body.