advanced-wetting-technologies

Dr Raymond Roberts
Consultant physicist

Dr Raymond Roberts
Consultant physicist

Firefighting

By far the majority of Class B fire fighting foams (flammable liquids) contain fluorochemicals create per- and polyfluoroalkyl substance (PFAS).  Fluoro based surfactants are very effective wetting agents and create effective firefighting foams. However they are long lasting chemicals and are called the "forever chemical" as they rarely break down in the environment. They are also present in 99% of mammals including most humans and are a known carcinogen because of the ubiquitous number of products that they are used in. Teflon is an example as is Scotch Guard.

Gluge_et.al._2020.pdf stated that "Fire-fighting foams. PFAS-containing fire-fighting foams are used for extinguishing liquid fires such as fires in oil, jet fuel, other non-water-soluble hydrocarbons, alcohols and acetone. Although relatively small quantities of PFAS are used in fire-fighting foams (class B for extinguishing î„„ammable liquid fires), these foams are an important use category because the foams and the chemicals they contain are released directly into the environment. There are numerous reports about PFAS-contaminated sites where fire-fighting foams have been used (especially for training activities) or spilled."

Because of their long lasting nature they last in ground water for decades and this has led to serious pollution, for example in the town of Katherine in the Northern Territory, the local water is unsuitable for human consumption. The same is the case for areas around the Williamtown airbase in NSW.

3M recently announced that by the end of 2025, they will exit manufacturing and work to discontinue the use of PFAS across its product portfolio.

3M will:exit all PFAS manufacturing by the end of 2025: 3M will discontinue manufacturing all fluoropolymers, fluorinated fluids, and PFAS-based additive products. We will help facilitate an orderly transition for customers. 3M intends to fulfill current contractual obligations during the transition period.

3M will work to discontinue use of PFAS across our product portfolio by the end of 2025: 

Foam manufacturers instead of claiming fluoro free foams are stating that foams with surfactants less than C8 are PFAS free which is a falsehood in that any fluoro chemical with greater than one CF molecule by definition is a polyfluoroalkyl substance. In any case any fluoro chemical subject to plasma (flame) can breakdown into hydrofluoric acid which is a caustic chemical that is highly corrosive, which means it immediately causes severe damage to tissues, such as burning or ulcers, on contact. Breathing hydrogen fluoride can damage lung tissue and cause swelling and fluid accumulation in the lungs (pulmonary edema). Skin contact with hydrogen fluoride may cause severe burns that develop after several hours and form skin ulcers. Hydrofluoric acid is one of the strongest acids known that has a strong lipophilic ability. Ingestions of more than 20 mg/kg body weight are considered a lethal dose.

AWT has developed a technology where the surfactants used in creating the firefighting foams is completely fluoro free and in fact is a more effective spreading agent and satisfies the UK DEF SPEC 42-40/2 standard for firefighting foam for Class B liquids. 

It was also flame tested at the University of New South Wales where it performed as well if not better than foams containing fluorochemicals. This is detailed in the following file. BASF_presentation_firefighting_foams_16_November_2020.pdf where spreading tests were conducted comparing AWT and fluoro containing foams.

AWT fluoro free foams are currently being commercially used on a small scale in fire extinguishers in Australia. These are the only true completely fluoro free foams manufactured in and used in Australia.