Clean agents extinguish fire by stopping the fire triangle/tetrahedron without leaving residue like water or dry chemical. Many clean agents work mainly by absorbing heat and lowering the temperature of the flame, and some also interrupt the chemical chain reaction. In certain systems, they can also reduce the available oxygen slightly, helping slow combustion. Clean agents are used in areas like server rooms, control rooms, and museums because they protect sensitive equipment and allow faster cleanup.

The main danger to personnel is that some clean agents can displace oxygen or affect breathing, especially in small or poorly ventilated spaces. Rapid discharge can also cause visibility problems, loud noise, and strong air movement. If a fire is still hot after discharge, some agents can break down into toxic byproducts (especially if exposed to high heat), so evacuation and ventilation procedures are important.