The increasing use of class A foam systems by urban and suburban fire departments for structural fire suppression has created a demand for information on this technology. While class A foams have been used extensively by wildland and rural fire departments, their application to structural fire suppression is a recent trend. This report discusses the use of class A foaming agents in conjunction with water for fire suppression (conventional or nozzle-aspirated class A foam systems); it also provides additional information on the use of class A foam agents with water and compressed air (compressed air foam systems, or CAFS).