Which type of fire extinguisher is used for ordinary combustible substances like wood and paper?

The Type A fire extinguisher is specifically designed for combating fires that involve ordinary combustible materials such as wood, paper, and certain types of textiles. These materials generally ignite and burn easily, making it crucial to use an extinguisher that is effective against them. Type A extinguishers usually contain water or a water-based agent, which smothers the flames and cools the burning material, helping to prevent re-ignition.

In contrast, other classes of extinguishers serve different purposes; for instance, Type B extinguishers are intended for flammable liquids like gasoline and oil, while Type C extinguishers are suitable for electrical fires. Type D extinguishers are designated for fires involving combustible metals, which require specialized agents to extinguish. Thus, the unique formulation and capabilities of the Type A fire extinguisher make it the appropriate choice for fires involving common combustibles like wood and paper.