Fluorine in extinguishing foams
Fire extinguishers with the extinguishing agent foam have been the most popular fire extinguishers for use in almost all indoor areas for many years. The reasons for this are high extinguishing performance, a wide range of applications and low secondary and consequential damage in the event of an extinguishing operation. Especially with the introduction of foam cartridge fire extinguishers, in the early 1990s, the powder fire extinguishers commonly used indoors until then were replaced.
Fluorosurfactants
Fluorosurfactants are used in industry for a variety of applications. They are used to reduce surface tension, which makes it possible to mix with substances (usually liquids) that could not normally be mixed easily. Known applications are, for example, paints, non-stick coatings for cookware, impregnations for textiles.
The function of fluorosurfactants in extinguishing foams
Fluorosurfactants ensure the formation of a water-containing film between the foam and the flammable liquid. By covering the entire surface of flammable liquids with this vapour-tight foam blanket, oxygen access is prevented (sticking effect) and the surface cools down (cooling effect). This is also known as AFFF - Aqueous Film Forming Foam.
The problem of perfluorinated hydrocarbons (PFC)
These compounds first came into the limelight with the so-called "PFC scandal", in which fertilisers contaminated with industrial waste were spread in the Hochsauerland region. As a result, considerable contamination with perfluorinated and polyfluorinated hydrofluorocarbons was found in the soil. A nearby reservoir was heavily polluted by washouts. The compounds were then also found in the blood count of the population in the surrounding area. PFCs are now considered persistent (not biodegradable), bioaccumulative (they accumulate in the food chain and in the human body) and toxic.
Restricted use of fluorosurfactants in fire-fighting foams
As the problem became known, the use of fluorosurfactants was increasingly restricted by EU directives. Some compounds of fluorosurfactants have already been banned altogether. The extinguishing agent industry has continued to improve and optimise the formulations for foam extinguishing agents. Today, only very small quantities of so-called short-chain (C6 telomers) products are used in conventional foam extinguishing agents.
Status Quo
The foam concentrates used in DÖKA fire extinguishers all comply with EU regulations. They are far below the required values of max. 25 ppb (=µg/kg). To give you an idea of the quantity in a 6 litre foam cartridge fire extinguisher. We use a foam concentrate which is only mixed with 1 %. The cartridge therefore contains just 0.06 litres of foam concentrate.
Up to date through regular service
Due to the regular extinguishing agent exchange, which is indispensable for foam fire extinguishers, even older DÖKA foam fire extinguishers are brought up to date. The old extinguishing agent is then disposed of properly by your fire protection dealer (the extinguishing agent is incinerated).
Fluorine-free alternatives
Bio+ - with BerkiCold
We have been offering fire extinguishers with the foam extinguishing agent BerkiCold for many years. These are known as so-called grease fire extinguishers, but are also approved for fire class B. With a rating of 13A and 144 B (6 extinguishing agent units - LE), the Si6BS Bio+ can be counted towards basic equipment according to ASR A2.2.
BerkiCold is also a true all-rounder. It extinguishes fires of fire class A (solids), fire class B (liquids) and grease fires (fire class F). In addition, BerkiCold is also suitable for lithium-ion batteries as it has excellent cooling properties. BerkiCold is completely fluorine-free and not harmful to humans, animals or the environment.
ECO - Fluorine-free foam for high performance
We use a new type of fluorine-free extinguishing agent in the Si6BS ECO fire extinguisher. This extinguishing agent achieves similar performance to conventional foam extinguishing agents. In extinguishing tests, the Si6BS ECO (6 litres of foam) achieved ratings of 27A and 144 B, which corresponds to 9 extinguishing agent units (LE).
