Which class of fire requires specific extinguishing agents like dry powder?

Class D fires involve combustible metals such as magnesium, titanium, and sodium. These types of fires behave differently from those involving common materials like wood, liquids, or gases. Because combustible metals can react violently with water and certain other extinguishing agents, specialized extinguishing agents, such as dry powder, are necessary. These dry powder agents work by smothering the fire and forming a barrier between the combustible metal and its oxygen supply, effectively suppressing the fire.

The importance of using the correct extinguishing agent is crucial in Class D fires to avoid exacerbating the situation. Since Class D materials can ignite easily and burn at extremely high temperatures, using inappropriate agents like water or foam can lead to dangerous reactions, making it vital to have the right type of powder designed specifically for fighting metal fires.