Which marking identifies a Class B fire extinguisher?

• A. Red Square
• B. Blue Circle
• C. Green Triangle
• D. Yellow Diamond

Answer: (A)

Fire extinguisher markings use color and shape on the label to show which class of fire it’s designed to fight. For flammable-liquid fires, the standard marking is a red square. The red color signals danger and the square shape helps you distinguish this class from others—blue circle for electrical fires, green triangle for ordinary combustibles, and yellow diamond for metal fires. So when you see a red square, you know the extinguisher is intended for Class B fires involving liquids like gasoline, oil, or solvents. Using the correct marking ensures you choose the right extinguisher for the fire type and use it safely.