Fire safety measures are a cornerstone of responsible property management, whether in residential, military, commercial, or industrial settings. Among the different types of fire suppression tools, AFFF (Aqueous Film Forming Foam) fire control systems stand out for their ability to defeat liquid fires.
These extinguishers utilize a unique mechanism that not only douses flames but also creates a barrier to prevent re-ignition.
This article explores the science that underlies AFFF, detailing how it operates and the various environments in which it excels. Additionally, it covers the discussion on the environmental impact of AFFF and potential alternatives.
The Chemistry Behind AFFF Foam
AFFF foam’s primary component is synthetic surfactants. These substances are crucial for their ability to suppress fires. Additionally, foam stabilizers are included to maintain the foam’s structure over time. Solvents also play a role; they ensure the even distribution of the foam’s ingredients.
The surfactants in AFFF have a dual purpose. Firstly, they significantly reduce water’s surface tension, allowing the foam to spread swiftly across hydrocarbon-based liquids.
Secondly, they aid in forming a thin yet resilient film that acts as a barrier, impeding the interaction between the fuel and oxygen. This ends up hastening the extinguishment of the fire.
The application of AFFF has a cooling effect on the fuel and its surroundings. This reduction in temperature is pivotal. It halts the spread of the fire and also serves as a protective measure for nearby structures.
The film-forming trait of AFFF is remarkable for sealing the surface of the flammable liquid. It acts as a barrier against vapor release, markedly diminishing the chances of re-ignition, which is particularly beneficial in scenarios where fires are prone to restarting.
Applications of AFFF Foam in Firefighting
AFFF shows its strengths best when deployed against Class B fires, which include fires from liquids like petrol, oils, and jet fuel. Its widespread use at sites such as airports, oil refineries, and naval facilities is due to the high incidence of such fires in these locations.
In comparison with other firefighting agents, including water and dry chemical substances, AFFF’s proficiency in quickly suppressing extensive liquid fires is unmatched. Its ability to form a vapor-blocking barrier is a distinctive characteristic that elevates it above other firefighting techniques.
Environmental and Safety Considerations
While the firefighting capabilities of AFFF are well-established, its environmental ramifications are particularly concerning.
Recent data from the Environmental Protection Agency (EPA) revealed almost 900 incidents of aqueous film-forming foam being used. These incidents have included substantial spills into waterways, with the largest one being 805,000 gallons at the Melbourne-Orlando International Airport.
Why is this significant? Well, some formulations of AFFF contain chemicals such as perfluoroalkyl and polyfluoroalkyl substances (PFAS), which have been linked to various health issues.
As TorHoerman Law states, PFAS are often referred to as “forever chemicals” due to their persistence in the environment and the human body. They have also been associated with an increased risk of certain cancers.
Many firefighters have indeed developed cancer and filed AFFF foam cancer lawsuits for compensation. Research indicates that firefighters face a heightened risk of cancer relative to the general population. The U.S. Fire Administration notes a 9% increased risk of developing cancer and a 14% higher risk of dying from cancer among firefighters.
Are There Any Better Alternatives to AFFF Foam?
As industries seek to reduce the environmental and health impacts of AFFF, several alternatives have been developed and are being adopted.
The search for safer alternatives has led researchers at the Johns Hopkins Applied Physics Laboratory to test certain ‘additives.’ This is done with the hope of enhancing the firefighting capabilities of PFAS-free fire suppressants for military use.
Many believe that the primary reason for these efforts is the Department of Defense mandate to phase out PFAS-containing AFFF by 2024.
One safe option is “fluorine-free foam.” These foams are designed to extinguish fires without the use of fluorinated surfactants. They rely on creating a foam blanket that cools and smothers the fire.
There is also research being done on dry chemical powders such as monoammonium phosphate or sodium bicarbonate. These work by interrupting the chemical reaction of the fire triangle (fuel, heat, and oxygen).
Options like gel-based agents, wet chemical agents, and C6 foams are also being developed. That said, transitioning to these alternatives can be a complex affair.
Conclusion
AFFF’s proficiency in extinguishing Class B fires is undeniable, yet the quest for environmentally benign substitutes that match its efficacy is pressing. Fluorine-free foams, dry chemical agents, and innovative additives are at the forefront of this pursuit.
These alternatives endeavor to balance fire safety with ecological and health stewardship, a balance that is becoming increasingly vital. As the deadline for the military’s transition away from PFAS-containing foams looms, the development and refinement of these substitutes take on added urgency.
Advancements will help not just the military but even civilian firefighters, who currently deal with the deadly side effects.
