Foam Extinguishers are ideal where both A & B class fire risks exist. AFFF (Aqueous Film Forming Foam) is particularly suited to class B fires caused by the combustion of materials that liquefy such as petrol, oils, fats, paints, tar etc. This equipment has passed the 35kv electrical conductivity test.   Class A Safe for wood, paper, textiles   Class B Flammable liquids   Not safe for live electrical equipment or flammable metal fires