Which extinguisher is generally used for Class B fires (flammable liquids)?

• A. Water
• B. Class K
• C. Dry chemical ABC
• D. CO2

Answer: (C)

For fires involving flammable liquids, the dry chemical ABC extinguisher is the best general choice. The powder blankets the liquid and creates a barrier between the fuel and the air, while also interrupting the chemical reactions occurring in the flame. This multipurpose agent is effective on a wide range of flames, including liquids, and it is safe to use on electrical fires as well.

Water is not suitable for flammable liquids because the liquid is lighter than water and will spread, potentially deepening the fire. Class K extinguishers are designed specifically for cooking oils, which is a narrow subset of Class B fires. CO2 can smother small fires by displacing oxygen but doesn’t provide a lasting blanket or residue to prevent reignition, and it’s less effective for larger liquid spills or enclosed spaces.