What color shape on a fire extinguisher represents a Class B fire?

The color shape that signifies a Class B fire on a fire extinguisher is a red square. Class B fires involve flammable liquids such as gasoline, oil, and grease, which are common in many environments. The use of a red square for this classification is critical, as it visually communicates the appropriate response needed for these types of fires, ensuring that individuals can quickly identify and select the correct fire extinguisher in an emergency.

Other colors and shapes represent different classes of fires. For example, a blue circle indicates Class C fires, which involve electrical equipment, while a green triangle typically represents Class A fires, which involve ordinary combustibles like wood and paper. Knowing these visual cues is essential for fire safety and effective firefighting response, especially in high-pressure situations where time is of the essence.