PFAS – Basics
PFAS are everywhere – in your rain jacket, in non-stick pans, in packaging and even in your drinking water. But what exactly are PFAS chemicals, and why is global and Swiss concern about these substances increasing?
PFAS in drinking water is no longer a theoretical issue – measurements show contamination in several regions of Switzerland. Here we explain in simple terms what PFAS are, where they occur, the health risks involved and how you can analyse your drinking water for PFAS to protect yourself and your family.
Definition of PFAS
PFAS stands for per- and polyfluoroalkyl substances – a group of more than 10,000 synthetic chemicals produced industrially since the 1940s. These substances are commonly referred to as “forever chemicals” because they hardly degrade in the environment.
The chemical uniqueness of PFAS lies in their extremely stable molecular structure: the bond between carbon and fluorine atoms is among the strongest in organic chemistry. This stability makes PFAS highly useful for industrial applications, but leads to severe environmental and health issues.
Why are PFAS called “forever chemicals”?
The term “forever chemicals” is hardly an exaggeration. PFAS possess extremely stable carbon–fluorine bonds that natural processes can barely break down. Their persistence in the environment lasts hundreds to thousands of years. Once released, they accumulate in soils, water, living organisms, and eventually the human body.
Learn more about chemical persistence
Chemical Structure of PFAS – What Makes Them Unique?
Molecular structure
PFAS consist of a carbon chain in which hydrogen atoms are fully or partially replaced by fluorine atoms. The two main groups are:
- Perfluorinated compounds: All carbon atoms are bonded to fluorine (e.g., PFOA, PFOS)
- Polyfluorinated compounds: Only partially fluorinated carbon chains
The best-known representatives are PFOS (perfluorooctanesulfonic acid) and PFOA (perfluorooctanoic acid), used for decades in many products.
Properties derived from structure
The special chemical structure gives PFAS unique properties:
- Water- and grease-repellent
- Heat-resistant to very high temperatures
- Chemically extremely stable
- Surface-active – they reduce surface tension
These properties make PFAS valuable for industrial use, yet environmentally problematic because conventional cleaning or degradation processes cannot remove them.
Simplified chemical structure
Key PFAS Compounds at a Glance
Where Are PFAS Used? – Everyday Applications
Industrial and commercial use
PFAS chemicals are nearly omnipresent in daily life. They are found in a wide range of products:
- Coatings: Non-stick pans, outdoor textiles, rainwear
- Packaging: Pizza boxes, fast-food packaging
- Firefighting foams: Agents for class B fires
- Cosmetics: Waterproof make-up, dental floss
- Medical devices: Certain instruments and equipment
- Electronics: Cable insulation, semiconductors
- Construction industry: Paints, varnishes, sealing materials
- Outdoor and sportswear: Swiss outdoor brands use PFAS-based impregnations
- Airports: Long-term use of PFAS-containing firefighting foams in Zurich and Geneva
- Ski sports: Ski waxes and impregnations
- Watch industry: Certain waterproof coatings
Environmental and Health Concerns
Environmental impact
PFAS enter the environment in several ways:
- Industrial wastewater
- Firefighting foams used in training areas
- Landfill leachate
- Sewage sludge applied to fields
A key aspect is bioaccumulation: PFAS accumulate in organisms and move up the food chain.
Health risks for humans
- Liver damage
- Elevated cholesterol
- Impaired immune function
- Increased cancer risk
- Hormonal disruption
- Developmental delays in children
- Thyroid disease
Particularly vulnerable groups
- Pregnant and breastfeeding women
- Infants and young children
- Occupationally exposed groups
Important: The biological half-life of PFAS in the body spans several years.
PFAS in Drinking Water
✔ 20 common PFAS chemicals
✔ Per- and polyfluorinated alkyl substances