🔍 Key Concepts

• Specific heat capacity of extinguishing agents (how much heat a substance can absorb per unit mass) • Difference between cooling the fire and smothering the fire • How various agents act on the fire tetrahedron (heat, fuel, oxygen, chemical chain reaction)

💭 Think About

• Which agent is primarily used because it can absorb a very large amount of heat when it changes state (for example, from liquid to vapor)? • Which agents mainly interrupt the chemical reaction or displace oxygen rather than absorb large amounts of heat? • Think about which agent is most effective on Class A fires (solid combustibles) specifically by cooling the fuel.

✅ Before You Answer

• Identify which option works mainly by cooling versus smothering or chemical interruption • Recall which medium has a high latent heat of vaporization (absorbs a lot of heat when it turns to vapor) • Eliminate agents that are primarily known for smothering (displacing oxygen) instead of cooling