CO2 acts on fire by reducing the relative oxygen content. This extinguishing agent has been successfully used for decades. It can be used for volume protection or object protection. CO2 systems are used to provide protection in unoccupied areas, as well as to protect objects in a simulated volume. It can also be used on deep fires by increasing the concentration levels. CO2 is a colorless and odorless gas. It is non-corrosive and non-conductive, leaving no residue after extinguishing.