What is a common characteristic of a Class B fire extinguisher?

A Class B fire extinguisher is specifically designed to combat fires that involve flammable liquids. This includes substances like gasoline, oil, grease, and solvents which are common in various settings, including agricultural environments where such materials may be used or stored. The effectiveness of a Class B extinguisher is attributed to its ability to smother the fire or interrupt the chemical reaction supporting combustion in flammable liquids.

By contrast, Class A extinguishers are meant for solid combustible materials such as wood, paper, and cloth. Class C extinguishers are designated for electrical fires, making them crucial in situations where electrical equipment is involved. Lastly, Class D extinguishers are used for fires involving combustible metals like magnesium or sodium. Each class of fire extinguisher is tailored to handle specific types of fires, which is critical for effective firefighting and safety.