What kind of safety situation would require a Class D extinguisher?

A Class D extinguisher is specifically designed to combat fires involving combustible metals, such as magnesium, sodium, and potassium. These types of metals can ignite and burn in a highly unpredictable manner, often resulting in fires that are not effectively extinguished by water or standard extinguishing agents used for other fire classes.

In contrast, other fire classifications require different types of extinguishing agents. For example, electrical fires necessitate agents that do not conduct electricity, while flammable liquids like gasoline require extinguishers that can suppress flammable vapors. Ordinary combustibles, such as wood or paper, can typically be handled with water or foam-based extinguishers. Therefore, the unique properties and behaviors of combustible metals warrant the use of a Class D extinguisher, making it the correct choice for the specified safety situation.