What is it?
PFAS are a family of over 12,000 synthetic chemicals that share an extremely strong carbon-fluorine bond, one of the strongest in chemistry. This bond is what makes them so useful industrially, and so dangerous biologically. They do not break down. Not in the environment. Not in your body. Scientists have detected PFAS in Arctic ice, in the blood of newborns, and in the organs of people who have never knowingly used a PFAS product.
What it does to your body
Thyroid disruption
PFAS interfere with thyroid hormone production and transport, linked to hypothyroidism, weight gain and fatigue.
Immune suppression
Children with higher PFAS levels show reduced vaccine antibody response. The immune system is among the most sensitive targets.
Cancer
Kidney and testicular cancer are the strongest associations. The EPA classified PFOA and PFOS as probable human carcinogens in 2023.
Hormonal disruption
PFAS block androgen and oestrogen receptors, affecting fertility, pregnancy outcomes and foetal development.
Liver damage
Elevates liver enzymes and is associated with non-alcoholic fatty liver disease.
Cholesterol elevation
Consistent association with elevated total cholesterol and LDL in population studies.
How widespread is the problem?
The CDC found PFAS in the blood of 97% of Americans tested. A 2023 EWG analysis found PFAS in the tap water of 200 million Americans. EU biomonitoring studies show widespread contamination across all demographics, with infants and young children showing disproportionately high levels relative to body weight.
Where it hides in your home
Key research
EPA PFAS Action Plan
EPA classified PFOA and PFOS as hazardous substances and set enforceable limits in drinking water for the first time.
NTP Report on PFAS Immunotoxicity
National Toxicology Program concluded PFAS are presumed to be an immune hazard to humans based on consistent evidence of reduced vaccine response.
EFSA PFAS Risk Assessment
European Food Safety Authority set tolerable weekly intake of 4.4 nanograms per kilogram bodyweight for four key PFAS combined, an extremely low threshold.
Half-life varies by compound. PFOS (found in older Scotchgard) can take up to 8 years for your body to eliminate half of what you have absorbed. PFOA (old Teflon) averages 3 to 4 years. Short-chain PFAS may clear in weeks, but are still bioaccumulative. Stopping exposure is the most important step.