Which type of fire is a Class D extinguisher specifically used for?

A Class D extinguisher is specifically designed for use on fires that involve flammable metals, such as magnesium, titanium, sodium, and potassium. These types of fires behave differently than those involving common combustible materials. Flammable metals can burn at very high temperatures and may react violently with water and certain chemicals, which is why specialized agents are necessary for extinguishing them. The extinguishing agents used in Class D extinguishers are effective at cooling and smothering these metal fires without causing an explosive reaction or worsening the situation. This distinct focus on flammable metals is what differentiates Class D extinguishers from other fire types, which require different firefighting approaches.