Aqueous film-forming foam (AFFF) is a synthetic-based foam that has been the go-to option to extinguish liquid fuel fires for decades.
However, AFFF foam contains per- and poly-fluoroalkyl substances (PFAS) as the primary ingredient. This substance can cause cancer and other serious health disorders in humans and animals, and pose a potential danger to the environment. In response to the negative impacts of PFAS, researchers have come up with several safer alternatives to AFFF foam, with fluorine-free foam being one of them.
This article will explain what AFFFs are, their shortcomings, the advantages of using fluorine-free foam, and why fluorine-free foams are being adopted as AFFF replacements.
Understanding AFFF Foam and Its Drawbacks
AFFF foams are water-based, fluorine-containing foams used to extinguish flammable liquid fires.
As they have low viscosity, they quickly cover the surface of the fuel, thus preventing contact with the fire and avoiding reignition. AFFFs have been highly effective at quickly extinguishing fires since being introduced commercially in the 1970s.
The problem lies in the fluorinated chemicals that allow AFFFs to spread across hydrocarbon fuels. These per- and polyfluoroalkyl substances (PFAS) are toxic and persist indefinitely in the environment.
Studies have linked PFAS to firefighting foams to a range of health effects in exposed individuals. These chemicals never break down and can accumulate in the human body and the environment over decades of exposure. This has earned them the alias of ‘Forever Chemicals’ as they are also impossible to destroy.
Firefighters face an elevated risk of firefighting foam cancer due to long-term occupational exposure to AFFF foams containing PFAS chemicals. Kidney, prostate, and testicular cancers are common occupational hazards. Studies reveal that firefighters using AFFF have unacceptable levels of Perfluorohexanesulfonic acid (PFHxS) and Perfluorooctanesulfonic acid (PFOS) in their bodies.
In addition, PFAS from AFFF has leached into groundwater at many military bases, manufacturing plants, and airports where firefighting drills are conducted. According to the Environmental Working Group (EWG), over 4600 locations across the U.S. are contaminated with PFAS. The Department of Defense (DoD) has also identified at least 400 infected military sites, but the EWG expects the number to cross over 700.
To protect the public from PFAS, the US Congress has enacted several laws that help monitor PFAS contamination, ban the use of PFAS, address ongoing PFAS contamination, and clean up the sites. Various states have already halted the production of PFAS, whereas other states have completely banned the use of PFAS in everyday products.
According to TorHoerman Law, the state of Maine was the first to initiate such restrictions, with other states soon following suit.
Introducing Fluorine-Free Foam (F3)
In response to these concerns, there has been a major push to switch to fluorine-free foams that avoid PFAS. Fluorine-free foams use synthetic detergents and increased hydrocarbon concentration instead of fluorosurfactants to achieve rapid extinguishment.
The main advantage of fluorine-free foams is they do not contain PFAS or other fluorinated chemicals. This eliminates the health hazards to firefighters and risks of environmental persistence and contamination.
However, fluorine-free foams fail to deliver the performance as compared to their fluorinated counterparts. According to the Industrial Fire Journal, they lack fire suppression capability, flexibility, applicability, and range of usage.
Moreover, a deep dive into its comparison with AFFF revealed that it needs to be refilled three times more to achieve the same level of fire protection. The F3 also falls short when it comes to controlling certain flammable liquids. Cold weather performance is another concern.
Bio-based fluorine-free foams derived from plant materials offer promising alternatives. But currently, synthetic foams tend to provide better fire extinguishment.
Making the Switch to F3
For fire departments, making the switch requires careful testing and evaluation to find the right fluorine-free foam for their needs.
As different foams have varying viscosities, equipment like proportioners, storage tanks, and nozzle assemblies may need switching to optimize the new foam’s performance. You also need to clean any previous AFFF-infected equipment if you’re using the same for F3. F3 products are easily contaminated by PFAS, even by a tiny amount of residue.
Firefighter training is also key when bringing in new foams. Firefighters will need education on what F3 is, its proper and optimal use, how they differ from AFFFs, and any differences in operating techniques.
Maintaining firefighting effectiveness should be the top priority when phasing out AFFF foams. While fluorine-free foams are safer, they must prove they can control and extinguish fires adequately.
In conclusion, the switch from Aqueous Film-Forming Foam (AFFF) to Fluorine-Free Foam (F3) is a crucial step toward addressing the environmental and health concerns associated with PFAS.
While AFFF’s efficacy in extinguishing flammable liquid fires is unquestionable, the long-term health risks and environmental persistence of PFAS demand a safer alternative. The path forward is clear — fluorine-free foams are the future.
With continued research and development, they will only become more effective and widely adopted. While challenges remain in making the transition, the health and environmental risks posed by legacy AFFFs make this change imperative.
With proper planning and training, fire departments can implement safer practices while upholding their duty to protect people and property. The time to phase out toxic firefighting foams is now.
