🔍 Key Concepts

• Class B fires (flammable liquids and gases) and how they react with different extinguishing agents • Properties of water vs. foam vs. fog patterns on flammable liquid surfaces • Why spreading the fuel or increasing vapor production can make a fire worse

💭 Think About

• Think about what happens when you apply a solid water stream directly onto a flammable liquid fire—does it cool, spread, or mix with the fuel? • Between high-velocity and low-velocity fog, which is more likely to push vapors and spread burning liquid, and which is gentler? • Which agent is specifically designed to create a blanket over flammable liquids and cut off oxygen and vapors?

✅ Before You Answer

• Identify which choices are primarily water-based and which provide a surface-sealing blanket over the fuel • Ask: For a Grade B flammable liquid (1,3-Pentadiene), do I want to cool from below, smother from above, or break up burning droplets? • Eliminate any option likely to agitate or spread the burning liquid rather than gently cover or smother it