Fires involving flammable liquids and gasses are which class?

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

Answer: (B)

Fires involving flammable liquids and gases are Class B. This category covers fuels that burn as liquids or vapors in air, like gasoline, solvents, propane, and natural gas. The hazard comes from vapors that can travel and ignite away from the initial spill, and water isn’t always effective and can even spread the fuel or cause more vaporization. Effective suppression targets the fuel itself or the vapor, using methods such as foam, dry chemical powders, or CO2 to blanket the flame and limit the flame’s contact with the fuel. In contrast, ordinary combustibles (wood, paper) burn as a different class, electrical fires involve energized equipment, and metal fires are handled separately.