🔍 Key Concepts

• How AFFF extinguishes flammable liquid (Class B) fires • Relationship between foam blanket, water content, and vapor suppression • Compatibility of AFFF with other extinguishing agents like dry chemical

💭 Think About

• Ask yourself: What is the MAIN extinguishing action of AFFF on flammable liquid fires—does it smother, cool, or stop vapors? • Think about whether AFFF foam is usually mixed with sea water, fresh water, or if it’s limited to one type only. • Consider what happens to a foam blanket if it is physically disturbed—does agitation ever break up foam layers in real firefighting situations?

✅ Before You Answer

• Verify how AFFF actually stops a fuel from burning: does it work by forming an aqueous (water) film over the fuel surface? • Check if standard marine fire-fighting doctrine allows AFFF to be used together with dry chemical agents. • Think about the word “cannot” in the choices—are the limitations described there consistent with how foam behaves in practice?