🔍 Key Concepts

• Dry chemical extinguishing agents and how they work compared with water or foam • The primary chemical action of dry chemical on the combustion process (especially on Class B and C fires) • The difference between smothering, cooling, and chain reaction interruption

💭 Think About

• Ask yourself: When you think of dry chemical on a flammable liquid fire, does it mainly cool, mainly smother, or mainly interfere with the burning process itself? • Which choice best matches the common textbook description of how dry chemical acts on the fire tetrahedron (fuel, heat, oxygen, chemical chain reaction)? • Consider which effect is most often highlighted for multipurpose ABC dry chemical agents in firefighting training materials.

✅ Before You Answer

• Identify which option refers to chemical chain reaction interruption rather than just physical blocking of oxygen or heat. • Verify which extinguishing effect is most commonly associated with Class B and C fire protection using dry chemical agents. • Eliminate any options that mainly describe how water or foam work instead of how dry chemical is usually described.