An international team of scientists, led by researchers in Australia, has successfully traced the entire breakdown process of per- and polyfluoroalkyl substances (PFAS) during incineration, offering a potential pathway for their safe and complete destruction.
PFAS, often referred to as “forever chemicals,” are widely used in consumer and industrial products but pose serious environmental and health risks due to their persistence and accumulation in nature.
The study, conducted by Australia’s national science agency CSIRO in collaboration with the University of Newcastle, Colorado State University, and the National Synchrotron Radiation Laboratory in China, provides critical insights into how these chemicals can be effectively eliminated through high-temperature incineration.
According to CSIRO Environmental Chemist and study co-author Dr Wenchao Lu, the research focused on perfluorohexanoic acid, a common type of PFAS.
“There are over 15,000 types of PFAS, but all of them share a strong fluorocarbon chain which doesn’t break down naturally,” Dr Lu said. “This is what makes them so persistent in our environments.”
One of the major challenges with PFAS incineration has been the incomplete breakdown of the chemicals, which can lead to the release of toxic byproducts into the air.
There is currently a moratorium on PFAS incineration in the United States, while regulatory uncertainty persists elsewhere due to concerns over emissions and incomplete destruction.
The researchers addressed this issue by using advanced detection methods at the National Synchrotron Radiation Laboratory to identify short-lived intermediary molecules formed as the chemicals burned.
“By taking ‘snapshots’ of the chemical reactions as they occur, we can see what intermediaries or harmful free radicals form inside the incinerator,” Dr Lu explained. “These chemicals had been hypothesised, but never actually detected.”
Professor Eric Kennedy from the University of Newcastle noted that identifying these intermediary molecules is crucial to ensuring complete destruction of PFAS.
“This study has identified intermediary molecules that are critical for us to ensure the PFAS molecule is completely destroyed, and to ensure no harmful byproducts are formed,” he said.
Colorado State University’s Professor Anthony Rappé emphasised the importance of international collaboration in addressing environmental challenges.
“This international team effort is illustrative of the collaborative environmental work that CSIRO leads,” he said.
The research highlights the importance of a process known as ‘mineralisation,’ in which the fluorocarbon chains in PFAS are converted into inorganic compounds such as calcium fluoride, carbon dioxide, carbon monoxide, and water.
These byproducts can be captured and potentially repurposed into industrial chemicals, concrete, fertilisers, and fuels.
While further research is necessary to refine the process, the findings represent a significant step toward addressing the global challenge of PFAS contamination.
These chemicals, commonly found in non-stick cookware, food packaging, and legacy firefighting foams, have long been associated with environmental persistence and potential health risks.
The study, titled ‘Direct Measurement of Fluorocarbon Radicals in Thermal Destruction of Perfluorohexanoic Acid Using Photoionization Mass Spectrometry,’ was published in Science Advances.
