What residue, if any, does a CO2 fire extinguisher leave when discharged?

A CO2 fire extinguisher operates by discharging carbon dioxide gas, which is effective in extinguishing fires primarily through smothering and displacing oxygen in the area of the fire. When CO2 is released from its pressurized form in the extinguisher, it converts to a gas and does not leave any significant physical residue after discharge. This unique property makes carbon dioxide extinguishers particularly suitable for use in enclosed areas or on electrical fires, as they do not cause additional contamination or mess after use.

In contrast, other types of extinguishers, such as those using dry chemical agents, can leave harmful residues that may require cleaning up after fire suppression. Therefore, the fact that CO2 leaves no residue whatsoever is an important feature for situations where cleanliness and the absence of chemical residue are a priority.