Understanding PFAS
PFAS is an acronym for per- and poly-fluoroalkyl substances, a class of 4,730 synthetic compounds. [1]
Molecular properties
PFAS are artificial substances with remarkable chemical and physical
properties, making them highly relevant to the industrial sector.
They are composed of a carbon chain that can be fully (perfluoroalkyl) or
partially (polyfluoroalkyl) fluorinated. The carbon chain can be composed of 4 to
16 carbon atoms. Specifically, short-chain PFAS have fewer than 7 carbon
atoms (6 in the case of sulfonates), while long-chain PFAS have 8 carbon atoms
or more. The carbon-fluoride (C-F) bond is the shortest and strongest known
covalent bond. They also have functional group heads, such as amines,
carboxylates, sulfonates, sulfates, and phosphates. [2–4]
PFAS exhibit high diversity in carbon chain length, degree of saturation,
branching, and functional groups, which allows them to be divided into many
subclasses. Although various classifications exist, there is a need to
standardise this process. [2]
These structures make PFAS hydrophobic, lipophobic and resistant to
chemicals and degradation. [1,3]
Figure – The most common PFAS types are PFOA (Perfluorooctanoic Acid) and PFOS (Perfluorooctane Sulfonate).
Industrial applications
Among the 4,730 PFAS molecules, “only” 256 (5,5%) are currently used
commercially. Their numerous physicochemical properties make them
extremely versatile in the manufacturing field. Thousands of tons are
produced annually due to their low costs.
PFAS are used in over 200 categories of consumer products, such as
surfactants, water-proof fabrics, firefighting foams, textiles and leather, oil-
repelling containers, semiconductors, non-stick cooking pans, food packaging,
shampoos, photo films, cleaners, masks, stain repellents, polishes, paints, and
coatings. [1,2,3]
References
