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Oxford Chemistry researchers have developed a method to destroy fluorine-containing PFAS (sometimes labelled 'forever chemicals') while recovering their fluorine content for future use. The results have been published today (26 March 2025) in Nature.
PFAS – which stands for poly- and perfluoroalkylated substances – have been produced in large quantities for over 70 years. They are found in a wide variety of products including textiles, food packaging, non-stick cookware, and medical devices. Their unique properties come from multiple carbon-fluorine chemical bonds, a particularly strong chemical motif that also explains their resistance to degradation.
This longevity has led to PFAS sometimes being referred to as "forever chemicals". Their persistence has resulted in widespread contamination around the world. Traces of PFAS have been found in drinking water and livestock, and have been associated with negative human health effects after chronic exposure .
This global problem urgently needs innovative technologies for the detection, recovery, and destruction of PFAS, as well as responsible pipelines to manage PFAS waste.
Now, a team of chemists at the University of Oxford and Colorado State University have shown it is possible to destroy a wide variety of these fluorine-containing PFAS chemicals while also recovering their fluorine content for reuse in industrial processes.
This operationally straightforward method works by reacting PFAS samples with potassium phosphate salts in the solid state. The reactants are ground together with ball bearings, which breaks down the long-lasting PFAS chemicals and allows the researchers to extract the fluorine content from the resulting product. In the study, the recovered fluoride was then used to generate common fluorinating reagents, which worked effectively in industrial reactions.
This recovery of fluoride, for re-entry into the fluorochemical industry, goes towards enabling a circular fluorine economy. This is particularly important given that fluorspar, the mineral from which essentially all fluorochemicals are manufactured, is categorised as critical for many industrial processes by nations around the world . Furthermore, the phosphate used as an activator in the PFAS destruction process was recovered and reused, implying no detrimental impact on the phosphorus cycle.
The team's method enables the mechanical destruction of all PFAS classes, including those commonly found in products such as non-stick coatings, electrical insulation, and industrial tubing. This means that the fluorine content from everyday waste such as Teflon tape could be recovered and used to generate important fluorine-containing chemicals, including precursors to pharmaceutical and agrochemicals such as cholesterol-lowering statin medications (Lipitor), anti-seizure agents (Rufinamide), and herbicides (Triaziflam).
A serendipitous observation made in the course of a previous study served as a starting point for the team's investigation. In an earlier set of experiments using a similar ball-milling method , they noticed that the PFAS-containing sealing rings of the ball-milling jars were degraded during the reaction, resulting in higher fluoride yields than expected. They concluded that their process must be breaking down the PFAS in these sealing rings and liberating fluoride. They wondered if the method may be able to break down and upcycle other examples of PFAS, and have now demonstrated that the method does indeed have broad applicability across a wide range of PFAS.
Professor Véronique Gouverneur (University of Oxford), who led the study, said:
"Fluoride recovery is important because our reserves of Fluorspar, essential for the manufacturing of e.g. life-saving medicines, are rapidly depleting due to extensive mining. This method not only eliminates PFAS waste but also contributes to a circular fluorine chemistry by transforming persistent pollutants into valuable fluorochemicals."
Dr Long Yang (University of Oxford), one of the lead authors of the study, said:
"The mechanochemical destruction of PFAS with phosphate salts is an exciting innovation, offering a simple yet powerful solution to a long-standing environmental challenge. With this effective PFAS destruction method, we hope to shift away from the notion of PFAS as 'forever chemicals'."
Work at Colorado State University was led by Marshall Fixman and Branka Ladanyi Professor Robert Paton as part of the Department of Chemistry in the College of Natural Sciences.
