Portable Fire Extinguishers Practice Test

Fires involving reactive metals need an extinguishing agent that can coat the metal, absorb a lot of heat, and prevent the metal from reacting with air. A dry powder does this effectively because its fine granules spread across the burning surface, form a protective crust, and smother the flame while cooling the metal. This specialized powder is designed specifically for Class D metal fires, so it works where other agents don’t.

Foam is best for liquid fires, creating a barrier on fuels like oil, not metal. Wet chemical is intended for commercial kitchen oils and fats, where it saponifies fats to form a soapy layer, not for metals. Dry chemical is a versatile option for many ordinary combustibles and some electrical fires, but it isn’t formulated to handle metal fires as effectively as a dry powder designed for Class D.