What indicates the class of a fire extinguisher?

The class of a fire extinguisher is indicated by a label that specifies the type of fire it is designed to combat. This classification system is crucial because different types of extinguishers contain various agents suitable for specific types of fires, such as those caused by ordinary combustibles, flammable liquids, electrical equipment, and combustible metals.

For example, a Class A extinguisher is effective on ordinary combustible materials like wood and paper, while a Class B extinguisher is designated for flammable liquids like gasoline or grease. This labeling helps ensure that users can quickly identify the right extinguisher for the situation at hand, thereby enhancing safety and effectiveness in emergency response scenarios.

Other options do not serve as indicators of the class of a fire extinguisher. For instance, size numbers refer to the quantity of extinguishing agent and not the fire type, a color code could vary among manufacturers and doesn’t provide universal identification of fire classes, and serial numbers are used for tracking and identification rather than indicating the class or type of fire the extinguisher can extinguish.