To understand the change to SFFF, a brief discussion is required on why AFFF has been the agent of choice over many decades for flammable liquid fire response.
In this article we are going to go over...
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Why AFFF foam has become popular for firefighting applications?
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Why AFFF is being phased out of firefighting?
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What you should expect from the new SFFF foam agents that are replacing AFFF agents?
Critical issues in the fire service today include improving firefighter health and safety, obtaining appropriate organizational funding, and providing adequate staffing and training. Fire officers can now add one more concern, the phase out of Aqueous Film Forming Foam (AFFF) for a new class of agents known as “Synthetic Fluorine Free Foam” (SFFF).
Why AFFF?
Since the 1960s AFFF has been the dominant Class B firefighting foam for vapor suppression and extinguishment of flammable liquid fire. The reasons AFFF became so widely used across the world are simple – compared to previous types, specifically protein-based foams, development of synthetic AFFF was a significant technological advance in our ability to knock down flame and suppress vapor. What’s more, it had longer shelf life, was relatively easy to proportion, had lower application rates, and was more forgiving regarding application technique when manually applied on burning flammable liquid surfaces.
Further, in many instances firefighters could apply AFFF effectively through standard fog nozzles without using special air aspirating nozzles or foam tubes. Simply, for these and other reasons it was a significant advance over the foam agents that came before it.
As a firefighting stalwart that has served us so well over many decades, why is AFFF being phased out now?
Why is AFFF Being Phased Out?
The makeup of AFFF contains what has become known over the last 25 years as a “forever chemical.” Known as per- and polyfluoroalkyl substances (PFAS), these are components of fluorosurfactants.
Fluorosurfactant chemicals are a key component of AFFF formulations which provide robust fire suppression performance. They are grease and oil resistant providing “oil hating” or oleophobic properties. This is highly desirable when a finished-foam blanket is in direct contact with a flammable liquid fuel surface since it resists contamination by repelling fuel pick up.
From an environmental perspective, PFAS is persistent, bioaccumulative, and toxic (PBT). From a health perspective, firefighter exposure may cause negative health consequences, such as increased risk of certain types of cancer.
Jurisdictions across the world have either already phased out, have passed legislation for future phase out, or are considering the phase out of AFFF firefighting foams due to PFAS environmental contamination and potential negative human health effects.
In one example, a state environmental agency in the northeast U.S. targeted levels of PFAS over 70 parts per trillion (yes, that is correct, parts per trillion) as unacceptable in the environment. That’s equivalent to a drop of water in an Olympic size swimming pool.
So, what should we expect with the phase in of new SFFF agents?
SFFF Agents
The overall sentiment throughout the fire industry is that SFFF agent performance is a downgrade over legacy AFFF performance. Essentially, with SFFF agents, the fire service loses several features and benefits of legacy AFFF applications. SFFFs are thought not to provide the same level of firefighting effectiveness when compared to AFFF application. But this is not to say that SFFFs are not good firefighting agents. Provided by reputable manufacturers the new SFFFs have been extensively tested and are third-party testing lab approved.