The Fluorine-Free Future of Firefighting Foam
Firefighting foam is one of the most important products in firefighting and is used to fight both class A (solid) and class B (liquid) fires. Its purpose is to cool and smother the fire, coating it to prevent its contact with oxygen and supress further combustion. Firefighting foam was invented in 1902 by the Russian engineer and chemist Aleksandr Loran. For fires involving ignitable liquids (class B) water is not an effective means of supressing a fire. Class B firefighting foams are a much more effective option. Currently, there are two main types of Class B firefighting foams available on the market: aqueous film-forming foam (AFFF) and fluorine-free foam. While both these products aim to achieve a similar outcome, their properties and functionality differ substantially.
AFFF is a synthetic-based foam that contains polyfluoroalkyl substances (PFAS) which are fluorinated, and hydrocarbon-based surfactants designed to create a film that coats and suffocates fire and fuel sources and cools any affected surfaces. The “fluorine” in AFFFs does not in fact have any relation to the element from the periodic table. The correct description would be PFCs (per-/poly-fluorinated chemicals), substances which do not occur in nature. They have been used in everything from coatings on non-stick pans to waterproof outdoor clothes. AFFF has long been the most commonly used, and efficient way to extinguish even the most challenging fires.
Fluorine-free foam is another synthetic-based foam that contains blends of surfactants and, in many cases, polysaccharides. These foams work slightly differently, creating a blanket of bubbles above fire fuels which cools and quickly extinguishes them.
For decades AFFF has been as essential to firefighters as water, owing to its unique qualities as a fast and reliable suppression agent. However, there is now unanimous agreement that usage of AFFFs must cease, and preferably as soon as possible. PFAS are known as “forever chemicals,” because once they have been released into the environment, they do not break down. This results in them accumulating in the food chain and therefore build up in our bodies and cause toxic effects. PFAS have been associated with cancer, developmental harms, reproductive issues, and damage to the immune system.
The knowledge of the risks of PFAS has resulted in the creation of the fluorine-free alternatives. Although these products are still toxic to the environment, they are fully biodegradable, so the risk of their accumulation in the ecosystem is substantially lessened. For this reason, they are considered to be the natural successor to PFAS, and the future of firefighting foams.
In the past 20 years manufacturers have made progressive improvements to these products. The issue has always been matching the performance of traditional AFFFs. Environmental and long-term health concerns must be weighed against the in the moment safety risks of large-scale fires. Fluorine-free foams must be just as effective, if not more so, at the task they are designed for to justify the necessary transition.
Safety concerns have included: Risks associated with an increase in the time it takes to extinguish a fire, issues with fuel sources reigniting and potential incompatibilities with existing equipment, training, and strategy. Fluorine-free foams have existed for a decade and have already been proven to be effective at extinguishing fires under the right conditions. The issue being these conditions have been somewhat limited. Unfortunately, however, the extinguishing effect of some products has shown to be significantly less effective than that of comparable AFFF foams. Also, their physical properties have proven to be a barrier to their widespread usage. They are usually very viscous substances, which can lead to proportioning problems and incompatibilities with existing equipment and procedures. The industry has been tasked to further improve these products in order to be able to completely dispense with fluorine compounds. In the past five years huge strides have been made, with a number of manufacturers at the forefront of these developments.
Dafo Fomtec manufactures and promotes an extensive range of Fluorine Free Foam Concentrates. Their Enviro range of products are all completely free of fluorosurfactants and fluoropolymers and the foam concentrates are tested and approved to international and industry standards appropriate to their applications. For example, the fire suppression mechanism of Fomtec Enviro ULTRA (to be used for class B hydrocarbon fuel fires) utilizes a blanket of foam to block oxygen supply to the fuel and the high-water content of the product cools the fuel surface. This reduces the evaporation of any flammable vapours and prevents the reignition of an extinguished fuel surface.
Orchidee manufactures a range of fluorine-free foams which provide top performance, combined with ultimate environmental protection. Besides Orchidex BlueFoamTM, they recently introduced two new products: ORCHIDEX FF ARC 3×3 F-HP and ORCHIDEX FF 3% HP. Both products are completely fluorine-free foam concentrates. ORCHIDEX FF 3% HP has been designed as one of world’s most stable foams on non-polar fuels. This slow draining and airtight foam provides maximum safety with outstanding burn-back resistance. ORCHIDEX FF ARC 3×3 F-HP is a high performance firefighting foam concentrate which is especially suited for applications on a variety of polar fuels. It provides rapid flame knockdown and maximum safety with outstanding burn-back resistance. The ORCHIDEX range of products are described as THE modern solution for firefighting of all fuel hazards with foam for mobile and fixed installations.
In 2002, BIOEX launched the first Fluorine-Free Foam which was effective on class A and class B fires. With its long experience, BIOEX has now developed a range of eco-friendly firefighting foams which offer a wide array of solutions to any risk. BIOEX eco-friendly firefighting foams are guaranteed to be free of PFAS and all fluorinated chemicals. They do not persist in the environment, are biodegradable and do not cause toxic effects. For example, ECOPOL PREMIUM multipurpose firefighting foam can be used on both class A and B fires, due to its wetting and expansion properties. ECOPOL PREMIUM has extinguishing performance comparable to AFFF foams and provides exceptional burnback resistance on flammable liquids.
Dr Sthamer produces the STHAMEX ® range of Multipurpose firefighting foams, which are all fluorine-free and 100 % biodegradable. They are a highly concentrated, thin liquid, which is suitable for use with all proportioning devices, negating prior issues with the use of these products with already existing equipment. They are suitable for low-, medium- and high-expansion foam applications. They are safe for use on non-polar class B fires and have excellent cooling properties. They can also be used for class A fires as expanded foam or as an effective wetting agent.
Perimeter Solutions has introduced the SOLBERG® VERSAGARD line of fluorine-free firefighting foam concentrates for general purpose uses. Some fluorine-free foams are more viscous than their AFFF counterparts and often show viscosity increase when in contact with water, leading to the previously mentioned issues with storage, handling, and long-term stability. SOLBERG VERSAGARD AS-100 multipurpose fluorine-free foam concentrate is designed for extinguishing both Class B and Class A fires and shows equivalent performance to existing AFFFs. The full range of products are fully biodegradable and do not persist in the environment. The concentrate is a combination of hydrocarbon-based surfactants, and additives, which is made without siloxanes and delivers excellent foaming, vapor sealing, extinguishment and burnback properties.
AUXQUIMIA®UNIPOL-FF™ 3/3S is another product from Perimeter Solutions is formulated with a special combination of hydrocarbon surfactants and pseudo-plastic polymers which provides excellent foaming, extinguish and burnback properties. It can be used to put out Class A and B fires and does not contain any fluorinated compounds. UNIPOL-FF 3/3S has been designed to be used with high, medium, and low expansion foam equipment and generate foams with high fluidity and slow drainage. While it is mainly used on hydrocarbon fires it can also be applied with forceful application, a capacity which up until now was reserved solely for AFFF agents.
The Fluorine-Free Future of Firefighting Foam is written by David Blackbourn Contributing Editor at Marcus Media.