What does the letter "B" in Type B extinguisher signify?

The letter "B" in a Type B extinguisher signifies that it is specifically designed for use on fires involving flammable liquids and gases. This classification includes substances such as gasoline, oil, paint, solvents, and other flammable fluids that can create hazardous fire situations. Type B extinguishers utilize agents that can effectively smother or suppress flames from these materials, which is crucial for ensuring safety in environments where such substances are present.

Understanding this classification is vital for ensuring the correct fire extinguisher is used in an emergency. Using an extinguisher not designed for the specific class of fire can exacerbate the situation, such as attempting to use a water-based extinguisher on a flammable liquid fire which could spread the flames. This highlights the importance of knowing the purpose of each type of extinguisher and their corresponding classifications in fire safety protocols.