Which class of fire extinguisher should be used on an appliance that is still electrically energized?

The use of a Class C fire extinguisher is specifically designated for fires involving electrical equipment. This classification is crucial when dealing with fires that have originated from energized electrical appliances or wiring. One of the key characteristics of Class C extinguishers is that they use non-conductive agents, which means they can effectively suppress the fire without the risk of electrical shock to the individual using the extinguisher.

Class A extinguishers are intended for ordinary combustible materials such as wood or paper, which would not be suitable for an electrically charged situation due to the potential electrical hazards. Similarly, Class B extinguishers are designed for flammable liquids and gases, while Class D extinguishers are meant for combustible metals, making them irrelevant for fires involving electrical components. Therefore, the correct choice emphasizes safety and efficacy when operating near energized electrical systems.