What is the fire rating for dry powder extinguishers?

Dry powder extinguishers are specifically designed for extinguishing flammable metal fires, which falls under Class D fires. These types of fires involve combustible metals such as magnesium, titanium, and sodium, which require specific extinguishing agents that can smother and cool the burning material without reacting adversely with it.

The fire rating of D indicates that the extinguisher is suitable for handling such unique fire hazards that are not addressed by the other classes (A, B, and C). For instance, Class A extinguishers are used for ordinary combustibles, Class B for flammable liquids, and Class C for electrical fires. Therefore, the right answer reflects the specialized nature of dry powder extinguishers in combating metal fires, and the D rating distinctly categorizes them for handling those specific emergencies effectively.