A new project out of Charles Darwin University focuses on developing fluorine-free firefighting foams that are just as effective as PFAS-based foams, but less toxic.
Spearheaded by Professor Bogdan Dlugogorski and Dr Vinuthaa Murthy, a new Charles Darwin University (CDU) project aims to improve the effectiveness of fluorine-free firefighting foams (F3).
Supported by the US Department of Defense, the project focuses on developing new additives and formulations that can one day lead to the manufacture of F3 as a viable replacement for toxic, PFAS-based foams. Currently, PFAS-based foams are the best performing fire suppressants, despite being a risk to the environment and health.
“Due to regulatory pressures to eliminate PFAS, fluorine-free firefighting foams are being developed as environmentally safer alternatives. However, current F3 do not match the performance of AFFF (Aqueous film-forming foam) in critical fire suppression scenarios,” said Dlugogorski.
“The need to improve F3 foams arises from a combination of regulatory, environmental, and performance factors.”
Titled Fuel Pick-up and Its Emulsification as a Means to Improve Fire Performance of Fluorine-Free Firefighting Foams, the project seeks to address a key limitation of F3, with its first-phase research expected to continue through 2027.
Born from a drive to innovate
Dlugogorski and his team at Charles Darwin University’s Energy and Resources Institute in Darwin were initially drawn to this issue by a combined interest to either recover, transport or transform energy.
“Hydrocarbons are still the most important energy carriers, and in those processes, there are a lot of risks, including fires and explosions. There’s no better way to fight fires than with firefighting foams,” he said.
However, Dlugogorski’s interest peaked when in 2000, 3M announced it would stop producing firefighting foams, despite being a leader in the manufacturing vertical.
“3M’s foams were the best, they worked very well. Yet, the company announced it was stopping. For us this was a shock, we thought ‘why would 3M do this?’” said Dlugogorski.
Yet, Dlugogorski would quickly learn that this move was no accident and was instead a result of the foams containing fluorochemical surfactants that were toxic, bioaccumulative and persistent in the environment. This inspired him to search for a safer, less toxic approach to firefighting foams, which he found while investigating the steady advancements of F3.
“We’ve been in this business for more than two decades. The F3 firefighting foams have been making steady progress, since the beginning of 2000 and especially within the last five to ten years,” he said.
Assembling a capable team
This research into F3 prompted Dlugogorski to assemble a skilled, multidisciplinary team that now resides out of Charles Darwin University.
“We have a broad team of people with different perspectives, from formulators of firefighting foams and developers of fire safety equipment to people who look at foams from a molecular perspective,” he said.
At the top of the list of influential team members is Ted Schaefer. Originally a formulation chemist with 3M Australia, Schaefer would be forced in a different direction when the company ultimately stopped producing firefighting foams.
“Ted was basically formulating PFAS foams, known as LightWater, that the Australian military was buying, with the foams also used at the Australian airports,” said Dlugogorski. “Once 3M withdrew from making the foams, he thought ‘what can I do better?’ This led Ted to being the inventor of one of the most important Australian discoveries – the first highly functional F3.”
Schaefer would develop F3 in 2002, start marketing it in 2003 and achieve great commercial success not long before 2009.
“Australia was one of the first to move from PFAS to F3, whereas the US is just doing this now, 15 years after,” said Dlugogorski.
Two other people that Dlugogorski said are vital to the research are David Meyer, the principal of Orion Fire Engineering, and Dr Vinuthaa Murthy, his co-lead and computational chemist.
“David is a success story in Australian manufacturing. He manufactures fire safety equipment and exports it to about 30 countries,” he said. “Vinuthaa basically analyses molecules and how those molecules arrange themselves and the interfaces around bubbles in firefighting foams.”
How harmful are PFAS foams, and why are they superior?
At the core of assembling such an expert team is the complex situation of a harmful yet effective compound.
Dlugogorski said that despite the progress made on PFAS based foams and several different projects aimed at removing toxicity, they will always be potentially harmful. The embodiment of an attempt to develop non-toxic PFAS-based foam took place in 2015 with a formulation referred to as C6 Pure. While ‘pure’ from other toxic aspects like C8 that have meant it’s not very harmful, it is still not biodegradable and persistent in the environment. This is the current PFAS technology offering on the market.
“Though the technology of PFAS foams has gone a long way, it’s still persistent. That’s why we prefer F3 even though they underperform compared to PFAS-based foams,” he said.
This reality led Dlugogorski to investigate the limitations behind F3, which currently he describes as “very good, but not excellent.” Within this investigation, he would discover that F3 falls short in performance because of a fundamental issue known as ‘fuel pick-up.’ F3 picks up between 20 to 50 percent of fuel, based on the water solution present in the foam. This becomes a problem in performance, as the more fuel that is picked up and mixed with the foam, the more likely it is for the foam blanket to ignite.
“Despite even higher fuel pick-up of AFFF, as high as 90 percent of fuel, PFAS-based foams make mixtures with fuel to be non-flammable, unlike F3. The present F3 doesn’t adequately stabilise the fuel during firefighting,” said Dlugogorski.
This pick-up issue within F3 means that while the foam will still extinguish the fire, it takes about 50 per cent longer for very large fires. This deficiency of F3 has a direct consequence to the involvement of the US Department of Defense as a collaborator and a sponsor on the project. This specific limitation presents itself for naval [offshore] applications, as at this moment, it’s not possible to use F3 on warships for safety reasons.
“Warships like aircraft carriers are isolated and must be self-reliant. They cannot call for a new fire brigade to come in. They are on their own in the middle of the ocean, and if an aircraft crashes on an aircraft carrier, firefighters need to take down the fire in 30 seconds, or at most a minute, before they lose the pilot,” said Dlugogorski. “In an application like this, at the moment we have no choice.”
The department’s involvement directly links back to a program called the Strategic Environmental and Research Development Program (SERD), which is dedicated to developing F3.
A plan to tackle a costly limitation
To address this issue, and to one day manufacture F3 capable of performing to the level of PFAS-based foams, Dlugogorski and his team have begun to target the realisation of the pick-up issue. This involves observing how PFAS operates, and how specifically, PFAS surfactants are very effective in separating oil and water.
“We’re trying to redress the situation by introducing new types of surfactants that are more effective in separating fuel and foam solutions,” he said. “The biggest difficulty is how to add the new set of surfactants to firefighting foams without changing their properties. If we are able to increase the performance, the next step is to make sure that we have the good properties for deployment. We would also have to do toxicity tests to ensure that the foams are no more toxic than the present generation.”
Dlugogorski said the path to reach the commercial manufacturing of effective F3 will take place in three stages, of which they are currently in the first.
“Now is time to demonstrate at a lab on a small scale – through numerical modelling and computational chemistry – that our surfactants would work,” he said.
In this phase, Dlugogorski and his team will be using small laboratory fires the space of around quarter of a square metre in surface area to
prove that the solutions have the same performance as PFAS foams. If successful here, the next step will be testing performance of larger fires of four-square metres. Eventually, he predicts that after several years, this will result in testing the solution on a 100 square metre fire, which will ultimately be the final step before commercialisation.
“Judging from Ted Schaefer’s experience, it’s still probably around six years away to be realistic,” said Dlugogorski.
Potentially broader implications
Despite looking a few years away from completion and commercialisation, Dlugogorski said if the new technology is successfully developed, it could have even more widespread applications. These could include improving the performance of cleaning products, water-resistant fabrics, nonstick cookware, cosmetic devices, food packaging and more.
“This technology could be transferable everywhere – where foam type materials are used and need to be stable in presence of oils, from ice cream to mayonnaise to emulsion explosives,” said Dlugogorski. “Funding of this research may have ramifications not only to firefighting foams, but also to a range of consumer products.”
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