🔍 Key Concepts

• CO2 fire extinguisher characteristics on Class B (flammable liquid/oil) fires • How CO2 extinguishes fire: oxygen displacement and limited cooling effect • Differences between CO2, foam, and water fog on oil fires

💭 Think About

• Think about what a CO2 extinguisher actually DOES to a fire and what it does NOT do well (cooling vs smothering). • Which option best matches the conditions under which CO2 will stop a liquid fuel fire before it spreads or flashes back? • Ask yourself: in real practice, when would CO2 alone be enough on a small oil fire without needing another agent?

✅ Before You Answer

• Verify which agent is best for preventing rekindling of hot oil: is it CO2 or foam? • Consider whether CO2 is normally used together with foam or as a stand‑alone agent on small liquid fires. • Remember that CO2 has no lasting blanket on the surface of the fuel; decide which choice lines up with that limitation.