Which type of fire extinguisher is appropriate for fires involving paints, solvents, or finishing liquids?

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

Answer: (D)

Paints, solvents, and finishing liquids create flammable-liquid fires, so the extinguisher you reach for must be rated for Class B fires. Class B extinguishers are designed to blanket and suppress flammable liquids, preventing vaporization and starving the flame of fuel. They handle hydrocarbon-based fuels like solvents and paints and are not reliant on water, which can spread the liquid and worsen the blaze. Extinguishers meant for ordinary combustibles tackle wood and paper and won’t control liquid fires, while those for electrical fires address energized equipment and don’t properly handle the fuel involved. So a Class B extinguisher is the appropriate tool for these kinds of fires.