What type of fire extinguisher is appropriate for an electrical control panel that has been de-energized?

When dealing with a de-energized electrical control panel, the appropriate type of fire extinguisher is one that is effective for electrical fires. A class C extinguisher is specifically designed to combat fires involving electrical equipment, as it uses non-conductive agents to put out the flames without posing a risk of electrocution.

Although other classes of extinguishers address different types of fires (such as solid combustibles, flammable liquids, or reactive metals), they are not suitable for use on electrical fires unless the power has been completely turned off, making the Class C extinguisher the safest choice when the equipment is de-energized. Using the wrong type of extinguisher, such as those for paper or wood (class A) or flammable liquids (class B), could lead to ineffectiveness in extinguishing the fire or create additional hazards. Therefore, the best option in this scenario is the Class C extinguisher, as it directly addresses the specifics of dealing with electrical fires that pose a risk when energized.