When can electrically conductive agents be safely used from a Class K extinguisher?

The safe use of electrically conductive agents from a Class K extinguisher occurs after the power has been turned off. This is crucial because Class K extinguishers are specifically designed for fires involving cooking oils and fats, and they utilize wet chemical agents that can also be conductive. If the power remains on while using such agents, there is a significant risk of electrocution for the person attempting to extinguish the fire, as the agent may conduct electricity and cause serious injury.

In the context of fire safety, ensuring that the power is off eliminates the risk associated with electrical conductivity of the agent. This is why waiting until the power has been turned off is essential before safely using these types of extinguishers.