As the world phases out use of PFAS-based foams in firefighting for the safer but less effective fluorine-free foams (F3), a new Charles Darwin University (CDU) project is aiming to increase the efficacy of this alternative foam.
Right now, PFAS-based foams continue to outperform F3. This delays fire suppression with F3, when every second counts, and prevents F3 from being deployed as a true drop-in replacement for PFAS-based foams.
The project aims to develop new additives and formulations to make F3 as effective as PFAS-based foams.
The project is led by CDU's Distinguished Research Professor Bogdan Dlugogorski and CDU Senior Lecturer in Chemistry Dr Vinuthaa Murthy, and is supported by the United States Department of Defense.
The Department of Defense was required to phase out PFAS-based foams starting in 2024, because PFAS compounds are known to persist in the environment ('forever chemicals') and have been linked to adverse health and environmental effects.
"Due to regulatory pressures to eliminate PFAS, fluorine-free firefighting foams are being developed as environmentally safer alternatives. However, current F3 foams do not match the performance of AFFF in critical fire suppression scenarios," Professor Dlugogorski said.
"The need to improve fluorine-free firefighting foams arises from a combination of regulatory, environmental, and performance factors.
"Each firefighting foam used forcefully against fires of liquid fuels picks up some fuel. The process is called fuel pick-up.
"The more fuel that is picked up and mixed with the foam means it is less likely to ignite."
Professor Dlugogorski said PFAS-based foams can pick up 50 to 90 percent of fuel, while fluorine-free foams pick up a lower amount, estimated to be 20 to 50 percent of fuel.
"PFAS-based foams make mixtures with fuel to be non-flammable, unlike F3. The present fluorine-free firefighting foams don't adequately stabilise the fuel during firefighting."
The project will consist of the researchers working to better understand the physics and chemistry of F3 and from there, developing new additives and formulations to improve the alternative.
Professor Dlugogorski said if new technology is developed, it could have widespread applications like PFAS, which is used in cleaning products, water-resistant fabrics, nonstick cookware, cosmetic devices, food packaging and more.
"If the project develops new technology, this technology could be transferable everywhere - where emulsion/foam type materials are used and need to be stabilised, from ice cream to mayonnaise to emulsion explosives," Professor Dlugogorski said.
Both researchers bring complementary skills and knowledge to the project, with Professor Dlugogorski's expertise in firefighting and formulation of F3 and Dr Murthy's in molecular modelling.
"This allows us to approach the problem of fuel pick-up from molecular perspectives, improving our chances to succeed," Professor Dlugogorski said.
The project, Fuel Pick-up and Its Emulsification as Means to Improve Fire Performance of Fluorine-free Firefighting Foams, will run through to 2027.
