Which fires should be treated with caution due to their association with reaction to water?

D class fires should be treated with caution due to their association with a dangerous reaction to water. Class D fires involve combustible metals such as magnesium, titanium, and sodium, which can react violently when exposed to water or moisture. This reaction can produce flammable hydrogen gas and intense heat, making the fire more difficult to control and potentially resulting in explosions.

Firefighters trained in handling Class D fires use special dry powder agents that are specifically designed to extinguish these types of fires without the risks associated with water. Understanding the nature of Class D materials is crucial for safety on the scene, as the inappropriate use of water can exacerbate the situation rather than help extinguish the fire.

Class A fires, which involve ordinary combustibles like wood and paper, can safely be extinguished with water. Class B fires involve flammable liquids and gases, which are better managed with foam or dry chemical agents rather than water. Class C fires include energized electrical equipment, where water can pose an electrical hazard, but do not have the same violent reactions associated with water as Class D fires.