What is a Class B/C fire extinguisher used for?

• A. Water spray extinguisher.
• B. Halon fire extinguisher.
• C. Foam extinguisher.
• D. Dry powder extinguisher.

Answer: (B)

Fires that involve flammable liquids and energized electrical equipment need an extinguishing agent that can handle both without harming sensitive avionics. A Halon extinguisher is a clean agent that rapidly interrupts the chemical reactions occurring in the flame and, because it leaves no conductive residue, can safely suppress fires in electrical gear as well as liquid-fuel fires. Water spray risks electric shock and can spread a liquid fuel; foam works for liquids but not for electrical fires; dry powder can cover multiple classes but leaves a residue that can damage electronics and is less ideal for rapid cooling. For a Class B/C fire scenario, Halon is the preferred choice.