Which of the following describes a key application for a 60-B fire extinguisher?

The key application for a 60-B fire extinguisher is specifically for fires involving flammable liquids. This type of extinguisher is typically filled with a dry chemical designed to effectively suppress fires fueled by combustible liquids such as gasoline, oil, and grease. Flammable liquid fires can be particularly dangerous due to their tendency to spread rapidly and the potential for flashbacks, making it essential to use the correct type of extinguisher that works effectively against this class of fire.

Understanding the specific applications of fire extinguishers is crucial for firefighting safety and efficiency. While extinguishers can sometimes be used on other types of fires, such as electrical fires or those involving rubber and plastics, the 60-B extinguisher is explicitly rated for flammable liquid fires, and using the wrong type could worsen the situation or pose additional risks. Therefore, the designation of a 60-B extinguisher highlights its suitability for combating flammable liquid blaze, which is a common risk in various environments.