Which type of fire extinguisher is most suitable for Class D fires?

A dry powder extinguisher is the most suitable choice for Class D fires, which involve flammable metals such as magnesium, titanium, and sodium. These types of fires require special extinguishing agents that can effectively smother the burning metal and prevent re-ignition. Dry powder extinguishers contain specific agents like sodium chloride or copper powder that create a barrier between the metal and the oxygen, thus suppressing the fire.

Other extinguishing agents, such as water-based, foam, or carbon dioxide extinguishers, are not effective for Class D fires. Water can react violently with the burning metals, potentially exacerbating the situation. Foam extinguishers are designed for flammable liquids and would not be effective with metals. Carbon dioxide extinguishers might not provide the same kind of suppression needed for these high-energy fires, which can allow for re-ignition. Therefore, the dry powder extinguisher is specifically formulated to tackle the unique challenges posed by Class D fires.