Which of the following is most true about applying dry powder to a Class D fire?

Which of the following is most true about applying dry powder to a Class D fire?

• A. Apply thick amounts directly to the burning metal
• B. Apply from a distance
• C. Apply thin dusting
• D. Mix with water before application

Answer: (A)

For Class D metal fires, the aim is to blanket the burning metal with a dry powder to isolate it from air and absorb heat, slowing or stopping the oxidation reaction. The most effective way is to apply thick amounts directly to the burning metal, building up a substantial layer that covers the surface and hot areas. A heavy, direct application ensures the powder stays in contact with the fuel, provides a strong heat-absorbing barrier, and reduces the chance of re-ignition. Applying from a distance or giving only a thin dusting won’t establish that protective coating and can let the fire continue. Mixing dry powder with water is not appropriate and can be dangerous with metals, as water can react violently with many reactive metals.

For Class D metal fires, the aim is to blanket the burning metal with a dry powder to isolate it from air and absorb heat, slowing or stopping the oxidation reaction. The most effective way is to apply thick amounts directly to the burning metal, building up a substantial layer that covers the surface and hot areas. A heavy, direct application ensures the powder stays in contact with the fuel, provides a strong heat-absorbing barrier, and reduces the chance of re-ignition.

Applying from a distance or giving only a thin dusting won’t establish that protective coating and can let the fire continue. Mixing dry powder with water is not appropriate and can be dangerous with metals, as water can react violently with many reactive metals.