When putting out a fire involving oily rags, which class of fire extinguisher is recommended?

• A. Class B
• B. Class A
• C. Class C
• D. Class D

Answer: (A)

Fires involving oily rags involve a flammable liquid fuel, so the extinguisher chosen must be able to handle liquids. Class B extinguishers are designed for fires where the fuel is a flammable liquid, such as oils or solvents, and they work by coating the liquid or separating the fuel from the flame. Other classes address different fuels—Class A for ordinary combustibles like wood or paper, Class C for energized electrical equipment, and Class D for certain combustible metals—so they aren’t the best fit here. Therefore, the recommended option is a Class B extinguisher.