ABC Dry Chemical Powder, multi-purpose fire extinguishers are truly versatile for extinguishing Class “A” (carbonaceous material) fire. It is also used on Class “B” (flammable liquid), Class “C” (flammable gas) and electrical engergise fires. This extinguisher works by forming a crust which insulates the material to prevent access to other combustible material nearby and smothering the fire to prevent oxygen from the atmosphere reacting with the material. EMACO ABC dry powder extinguishers are ideal for residential, commercial and industrial applications.