Most effective tactic for combating Class D fire?

• A. Ventilate and isolate
• B. Spray water from distance
• C. Apply foam directly to base
• D. Jettison

Answer: (D)

Class D fires are metal fires, where the burning material is the fuel itself. Water and foam aren’t effective here because many metals react violently with water and the burn isn’t a hydrocarbon flame that a foam blanket can smother. The most effective tactic is to remove the burning metal from the vessel if it can be done safely, jettisoning it overboard to take away the fuel source and reduce heat and risk to the surrounding structure. If removing the metal isn’t possible, you would use a dry powder or other smothering agent to blanket the fire, but removing the fuel is the quickest way to stop the reaction. Ventilating would supply more oxygen to the flame, and spraying water or applying foam directly to the base doesn’t reliably extinguish metal fires.