Which term refers to an extinguishing agent that leaves no residue upon evaporation?

• A. Halocarbon Agent.
• B. Inert gas agent.
• C. Clean Agent.
• D. Aqueous film-forming foam.

Answer: (C)

This question tests that some extinguishing media leave no residue after evaporation. Clean agents are designed to extinguish by absorbing heat or interrupting flame chemistry and then disperse as a gas, so they don’t leave any residue on surfaces as they dissipate. This makes them ideal for protected areas with sensitive equipment where cleanup or residue damage would be a concern. Aqueous film-forming foam, by contrast, leaves a persistent film and requires cleanup, so it doesn’t fit the no-residue idea. While inert gas and halocarbon agents are types of clean extinguishing media, the term that specifically denotes the lack of residue after evaporation is clean agent.