Researchers at Northwestern University in the US have claimed a breakthrough in breaking down perfluoroalkyl and polyfluoroalkyl substances (PFAS), which are used extensively in cosmetics.
Chemists at the Illinois institute have developed a process to that cause these two major classes of PFAS compounds, to fall apart using low temperatures and inexpensive, common reagents - leaving behind only benign end products.
FAS has been in use for around 70 years in cosmetic products, including lotions, cleansers, nail polish, shaving cream, foundation, lipstick, eyeliner, eyeshadow, and mascara, to condition and smooth the skin, making it appear shiny, or to affect product consistency and texture.
PFAS are so-called ‘forever chemicals’, as some forms of PFAS can take over 1,000 years to degrade as they contain carbon-fluorine bonds, which are the strongest bonds in organic chemistry.
However, the Northwestern University team found a weakness.
At one end of the molecule, there is a charged group that often contains charged oxygen atoms that was targeted by heating the PFAS in dimethyl sulfoxide with sodium hydroxide, a common reagent.
The process decapitated the group, leaving behind a reactive tail.
“That triggered all these reactions, and it started spitting out fluorine atoms from these compounds to form fluoride, which is the safest form of fluorine,” said Northwestern’s Professor William Dichtel, who led the study.
“Although carbon-fluorine bonds are super strong, that charged head group is the Achilles’ heel.”
The study, ‘Low-temperature mineralization of perfluorocarboxylic acids’, was supported by the National Science Foundation.
