In an automotive shop, which extinguisher type is appropriate for flammable liquids and electrical fires, and where should you aim?

• A. Use a CO2 extinguisher; aim at the ceiling.
• B. Use a water extinguisher on all fires; aim at the flames.
• C. Use a Class D extinguisher for vehicle fires; aim at the upper part.
• D. Use a Class B or ABC extinguisher as appropriate for flammable liquids and electrical fires; aim at the base of the fire.

Answer: (D)

Dealing with fires in an auto shop requires using an extinguisher rated for the types of fire you might encounter. For flammable liquids and electrical fires, you want a Class B or an ABC extinguisher. Class B is designed specifically for flammable liquids, while Class C covers electrical fires; an ABC extinguisher combines these capabilities, making it a practical, versatile choice in a shop where you could face either liquid fuel fires or electrical equipment fires. The most important technique is to aim at the base of the fire—the part at the source of the fuel—and sweep the nozzle from side to side to blanket and knock down the flames. If it’s safe, shut off power first and use the extinguisher only if you can do so without risking yourself. Other options aren’t suitable: aiming a CO2 extinguisher at the ceiling reduces effectiveness and can be hazardous in a shop; water is unsafe on electrical or hydrocarbon fires; and Class D is for metal fires, not typical vehicle fires.