🔍 Key Concepts

• Fire classes (A, B, C) and what materials they cover • How dry chemical extinguishers actually put out a fire • The difference between surface fires (like liquids) and deep-seated fires (like mattresses)

💭 Think About

• For each option, ask: what class of fire is this mainly (A, B, or C)? • Think about which situation might allow the fire to re-ignite internally even after the surface looks out, especially when using a powder agent. • Consider where dry chemical is very commonly recommended and where another type (like foam or water) might be preferred for best results.

✅ Before You Answer

• Verify which materials are in Class A (ordinary combustibles), Class B (flammable liquids), and Class C (energized electrical equipment). • Check where an ABC dry chemical extinguisher is specifically designed to be used effectively and safely. • Ask yourself: in which option would powder mainly coat the surface but have trouble penetrating the burning material?