Scientists Discover Easy Way to Destroy ‘Forever Chemicals’

Scientists have discovered an "Achilles heel" in two popular classes of PFAS (per- and polyfluoroalkyl substances). A simple and affordable method helps to decompose these substances, known as “forever chemicals”, into safe components.

Chemists from Northwestern University have developed a new decomposition method for two classes of PFAS containing carboxylic acid. The technology works at normal temperatures and requires only inexpensive reagents.

The secret of the stability of PFAS is in the bonds of carbon with fluorine. These are the strongest bonds in organic chemistry, which are extremely difficult to break. But when studying compounds of perfluoroalkyl carboxylic acids, scientists discovered that at one end of the molecule there is a group that contains charged oxygen atoms.

The researchers used a solvent focused on this group. To do this, they heated the PFAS in dimethyl sulfoxide with sodium hydroxide. Such an impact destroyed the "head group" of the molecule and started the processes of further disintegration of the substance. At the same time, the material isolated fluorine atoms in the form of fluoride, the safest possible form, the authors of the study say.

“We were pleased to find a relatively low temperature, low energy input method where the one specific portion of these molecules falls off and sets off a cascade of reactions that ultimately breaks these PFAS compounds down to relatively benign products including fluoride ions… that are in many cases found in nature already and do not pose serious health concerns,” William Dichtel, a professor of chemistry at Northwestern University said, as quoted by The Times.

PFAS is a class of chemicals with very strong fluorocarbon bonds. They are often called "forever chemicals" because they are extremely difficult to destroy. Bacteria can't eat them, fire can't incinerate them, and water doesn't dilute them. Since the 1940s, these substances have been actively used as non-stick and waterproofing agents.