What is Class B fire and the typical extinguishing approaches?

• A. Electrical fires; water is always best.
• B. Ordinary combustibles; water only.
• C. Flammable liquids; use foam or dry chemical, CO2, or ABC; focus on cooling and separation from fuel.
• D. Metal fires; use water aggressively.

Answer: (C)

Class B fires involve flammable liquids, and the goal is to cool the fuel to below its ignition point while also creating a barrier between the liquid and the air or fuel source. Foam is especially effective here because it blankets the liquid surface, cools the fuel, and slows vapor release, helping to starve the flame. Dry chemical powders and CO2 can smother or interrupt the flame chemistry, and an ABC multipurpose extinguisher covers these kinds of fires as well. Water is generally not the first choice for hydrocarbon or other flammable-liquid fires because it can spread the liquid and make the fire harder to control. So the best answer points to flammable liquids and the use of foam or dry chemical, CO2, or ABC, with the emphasis on cooling and separating the fuel from the flame.