What type of combustion substances are involved in Class A fires?

Class A fires are specifically associated with ordinary combustible materials such as wood, paper, cloth, rubber, and certain types of plastics. These materials are characterized by their ability to ignite and sustain combustion when exposed to an open flame or spark. The significance of recognizing Class A fire substances lies in the appropriate extinguishing methods, which typically involve the use of water or foam to cool the burning materials and deprive them of oxygen.

The other substances listed, such as flammable liquids, electrical materials, and combustible metals, are classified under different fire classes: Class B for flammable liquids, Class C for electrical materials, and Class D for combustible metals. Each class requires specialized knowledge for firefighting techniques and safe handling, making it crucial to distinguish Class A combustible materials from these others, which have distinct properties and risks associated with them.