Which class of fire extinguisher is represented by a solid red square?

The class of fire extinguisher indicated by a solid red square corresponds to Class A fire extinguishers, which are designed for use on ordinary combustible materials such as wood, paper, cloth, and some plastics. Class A extinguishers are typically filled with water or water-based agents that cool the fire and remove heat from the fuel source, making them effective for these types of fires.

It's essential to recognize the color coding used on fire extinguishers, as it helps firefighters and the public quickly identify the appropriate type of extinguisher needed for certain classes of fires. Class C, for example, is designated by a blue circle for electrical fires, while Class B fires involve flammable liquids and are indicated by a red square. Class D extinguishers are used for fires involving combustible metals and are marked with a yellow star. Understanding this classification system is critical for effective fire response and safety.