Class A Fuel : Materials such as vegetation, wood, cloth, paper, rubber, and some plastics in which combustion can occur at or below the surface of the material
NFPA 1150 Standard on Foam Chemicals for Fires in Class A Fuels, 2004 ed. http://www.nfpa.org/Assets/files/AboutTheCodes/115 0/1150-F2009-ROC.pdf, (Std: Foam Chem for Fr in Class A Fuels - Amer) {387 NFC}