What is a class A fire extinguisher?

A class “A” fire extinguisher is designed and will extinguish most fires that have started from naturally occurring combustible materials like paper products, wood, cloth, some plastics, and other refuse. It contains the chemical ammonium phosphate, which will smother the fire and leave a yellowish residue/powder behind. This chemical is corrosive and should be cleaned up immediately after use. Most standard fire extinguishers will be a combination of A, B, and C.