Foam fire extinguishers are suitable to extinguish fires in liquids and solids such as wood, paper or textile. (Class A and B) They are classified as universal extinguishers which everyone should have at home. Fire fighters also mostly use extinguishing foams for fighting fires in addition to water.
Fire extinguishing foam quickly forms a dense blanket on the burning object so that oxygen is withdrawn from the flames. The tight but still very light foam will remain even on burning liquids. At the same time the foam cools the fire, which, in combination adds up to excellent extinguishing properties. Extinguishing foam spreads itself on the burning surface and accumulates to a gas-tight blanket under which the flames immediately suffocate.
Whereas dry powder distributes itself in every crack and has a corrosive effect on metals, chemical foam hardly causes any damage. The foam can be removed almost without any trace which makes foam extinguishers a very popular all-round extinguisher for home use.
Extinguishing foam in F-Exx extinguishers
Extinguishing foam is produced by foaming a mixture of water, air and foaming agents. There are a number of different chemical foam agents: A distinction is made between protein foam which is developed on the basis of horn shavings and various foam concentrates containing, amongst others, surfactants, such as fluorosurfactants, alcohol or urea. With foam extinguishers made by Tectro the extinguishing foam consists of aqueous solutions of various soaps (surfactants). In the case of frost-proof all-round extinguishers antifreeze (up to -20 ° C) is achieved by using a combination of alcohols and salts. This means that all F-Exx extinguishers are absolutely non-toxic and can be used safely in the home.