Which symbol represents a Class D fire?

The symbol that represents a Class D fire is a yellow triangle with a "D" in the center. Class D fires involve combustible metals such as magnesium, titanium, and sodium, which require special extinguishing methods and agents often indicated by this unique symbol. The yellow triangle is a widely recognized representation within fire safety to alert individuals to the specific hazards associated with combustible metals.

Using a yellow triangle helps in differentiating Class D fires from other classes, making it crucial in environments where metal fires might occur. It's important for first responders and individuals in industrial settings to quickly identify this symbol to ensure they use appropriate firefighting measures, as many standard extinguishing agents are ineffective or dangerous when applied to metal fires.

The other symbols listed—red square, blue circle, and green rectangle—represent different classifications or types of fire and are not indicative of the risks associated with combustible metals. Thus, familiarity with this specific symbol not only supports safety but aids in effective fire prevention and firefighting strategies.