How should a firefighter use a dry chemical extinguisher in a structure fire?

• A. Puncture the canister and spray into the smoke.
• B. Target the base of the fire with sweeping motions while maintaining situational awareness and transitioning to water if needed.
• C. Aim at the ceiling to suppress smoke.
• D. Spray in a straight stream toward the top of flames.

Answer: (B)

Attacking a structure fire with a dry chemical extinguisher centers on quickly separating the fuel from the flame by coating the base of the fire. You aim at the base and sweep the nozzle from side to side, staying low and moving across the fire to cover the fuel source. This directs the dry chemical to interrupt the chemical reactions fueling the flame and prevents the fire from re-igniting as you progress. Throughout, stay aware of your surroundings and be ready to switch to a water application if conditions require cooling or deeper knockdown. Aiming at the ceiling or spraying into the smoke doesn’t reach the fuel at the base and is ineffective, and puncturing the canister would be dangerous and wasteful.