Which class of fires includes flammable liquids, grease, gasoline, and oil-based paints and thinners?

Which class of fires includes flammable liquids, grease, gasoline, and oil-based paints and thinners?

• A. A
• B. C
• C. B
• D. D

Answer: (C)

Fires involving flammable liquids like gasoline, greases, oils, and oil-based paints are Class B. These fuels burn as liquids, so the extinguishing approach targets removing or isolating the liquid fuel rather than cooling the surface. Water tends to spread or splash these liquids, making it ineffective for Class B fires; instead, use a suitable extinguisher such as dry chemical, foam, or CO2 that interrupts the chemical reaction or separates the fuel from the fire. For grease fires in kitchens, the principle is the same—smother or use a Class B-rated agent rather than water. Other fire classes correspond to different fuels: ordinary combustibles (wood, paper, cloth) are Class A; energized electrical equipment fires are Class C; and combustible metals (like magnesium) are Class D. The described fuels clearly fit Class B.

Fires involving flammable liquids like gasoline, greases, oils, and oil-based paints are Class B. These fuels burn as liquids, so the extinguishing approach targets removing or isolating the liquid fuel rather than cooling the surface. Water tends to spread or splash these liquids, making it ineffective for Class B fires; instead, use a suitable extinguisher such as dry chemical, foam, or CO2 that interrupts the chemical reaction or separates the fuel from the fire. For grease fires in kitchens, the principle is the same—smother or use a Class B-rated agent rather than water.

Other fire classes correspond to different fuels: ordinary combustibles (wood, paper, cloth) are Class A; energized electrical equipment fires are Class C; and combustible metals (like magnesium) are Class D. The described fuels clearly fit Class B.