Fire fighting foam is one of the most important products in fire fighting and is used to fight class A (solids) and class B (liquids) fires. The chemical composition has some special characteristics.
The so-called “fluorine” in some foaming agents (AFFF, AFFF ARC, etc.) has little in common with the element from the periodic table. The correct description would be PFCs (per-/poly-fluorinated chemicals), which describes a group of approx. 100 substances. Substances from this group do not occur in nature but are used for a variety of products. They are used in everything from pan coatings and outdoor clothing to special foaming agents for fire departments.
The great advantage of these PFCs is that they can make products dirt- and water-repellent as well as heat- and chemical-resistant. This has also been used for years in fire fighting by successfully using AFFF foam compound for larger liquid fires. Here, special properties of some PFCs cause a film to form between the extinguishing foam and the burning hydrocarbon, which is gas-tight and accelerates the spread of the foam covering.
So far so good. But these perfluorinated chemicals also have the great disadvantage that these compounds are practically not degraded and therefore accumulate in the food chain and also show toxic effects.
The alternative are “fluorine-free” foam compounds, such as multi-application foam compounds, or Class A foam compounds. Although these are still toxic to living organisms, they are completely biodegradable. For this reason, they are the compound of choice in most cases.
Only in the case of large liquid fires or alcoholic liquid fires do these foam concentrates reach their limits. This is where the fluorine-free alcohol-resistant fire fighting foam comes into play.
Unfortunately, however, this foam compound is not without its disadvantages. The extinguishing effect of some products is significantly worse than that of comparable AFFF foams. In addition, they are usually very viscous, which can lead to proportioning problems.
The industry is called upon to further improve these products in order to be able to completely dispense with fluorine compounds in fire fighting foams in the future!
As an innovative company, Rosenbauer is leading the way in this area and already has products in its portfolio that point the way to a “fluorine-free future.” Foammaster 3F as alcohol-resistant, fluorine-free fire fighting foam, which achieves very good ratings in a wide range of standard tests (EN-1586, Lastfire, UL…) and is also adequately mixable with a viscosity of 120 mm²/s. Or Airfoam, which has a water-like viscosity, can be used in airports with ICAO Level B approval and is the world’s first fluorine-free fire fighting foam to form a film!
Further information about fluorine-free foam compound in the blog article “Proportioning technology for fluorine-free foam compound”.