Dry powder extinguishers can be used for A, B, and C.

• A. A only
• B. B only
• C. A, B, and C
• D. D only

Answer: (C)

Dry powder extinguishers are a versatile type that can handle three common fire classes: ordinary combustibles, flammable liquids, and energized electrical equipment. They work by coating the fuel, interrupting the chemical reactions occurring in the flame, and forming a crust that helps prevent reignition. Because they are rated for all three classes, the best answer is the one that indicates coverage of all three categories. If you thought it only applied to one or two classes, you’d miss the extinguisher’s broad rating. One practical note: the powder leaves a residue that can be difficult to clean and may affect sensitive electronics, so consider the context when choosing an extinguisher.