🔍 Key Concepts

• Foam fire-fighting agents and how they work on liquid (Class B) fires • Difference between smothering a fire and cooling a fire • Dangers of using solid streams of water on oil or fuel fires

💭 Think About

• Think about what happens when foam lands on the surface of burning oil — what physical layer or barrier does it create? • Consider whether applying a solid stream of water onto burning oil will spread or control the fire. • Ask yourself: does foam mainly protect firefighters from heat, cool the fuel, or interrupt the fire’s access to oxygen?

✅ Before You Answer

• Verify the primary function of aqueous film-forming foam (AFFF) or other foams on fuel fires. • Check what can happen if water and burning oil mix or if water is used improperly. • Distinguish between smothering (blocking oxygen) and cooling (reducing temperature) as fire-extinguishing methods.