Foam fire extinguishers are ideal for multi-risk situations where class A and B risks exist. Class B fires, those involving flammable liquids, such as petrol, diesel, spirits, solvents and lubricants, can be tackled very effectively. The foam fire extinguishers, which are available in both gas cartridge and stored pressure versions, contain an aqueous film forming foam which gives rapid flame knock-down and has a blanketing effect, smothering the flames and sealing vapours to prevent re-ignition.