Which classification of fire involves ordinary combustibles such as wood and paper?

The classification of fire that involves ordinary combustibles such as wood and paper is Class A fire. Class A fires are characterized by the burning of materials that are commonly found in households and workplaces, making them accessible and widespread. These fires are fueled by solid combustible materials, including wood, paper, cloth, rubber, and some plastics.

The extinguishing agents that are effective on Class A fires typically include water and multi-purpose dry chemical extinguishers. Water cools the burning material and can help to smother the flames, while dry chemical agents can interrupt the chemical reaction of combustion.

In contrast, other classes of fire involve different types of materials: Class B fires involve flammable liquids and gases, Class C fires pertain to electrical equipment, and Class D fires are related to combustible metals. Understanding these classifications is crucial for selecting the proper extinguishing method and ensuring safety during firefighting operations.