Foam Class Types

Firefighting foams can be put into two very broad classifications: Class ‘A’, and Class ‘B’. Each of these classifications corresponds directly to the types of fuels on which the foams are designed to be used. Understanding this is a very important first step. Class ‘A’ foam is not designed to put out Class ‘B’ fueled fires. While each foam class may have similar white and bubbly features, they are nevertheless not chemically compatible. While using a Class ‘A’ foam for a flammable liquids (Class ‘B’) fire may extinguish some of the easier fuels, results could be catastrophic because of its inability to secure the explosive vapors of tougher fuels.