What does the yellow star symbol indicate in fire extinguishers?

The yellow star symbol on fire extinguishers indicates that the extinguisher is suitable for use on Class D fires, which involve combustible metals such as magnesium, titanium, and sodium. These types of fires require special extinguishing agents because water and standard foam or dry chemical extinguishers can react violently with the burning metals, potentially making the situation worse.

Class D fire extinguishers are specifically designed to combat these hazardous fires, employing unique chemical agents that effectively smother and cool the burning metals without causing additional reactions. Understanding these classifications is critical for effective fire response and ensuring safety during fire incidents involving specific materials, particularly in industrial environments where such metals are commonly used.

On the other hand, Class A fires involve ordinary combustibles, Class B fires pertain to flammable liquids, and Class C fires involve electrical equipment; thus, their symbols and classifications differ significantly from Class D, which is specifically focused on hazardous metal fires.