Carbon dioxide fire suppression systems are the oldest gaseous fire suppression systems that are in use to date. Carbon dioxide is a colourless, odourless gas which is non-conductive to electricity.

The principle of fire extinguishing is to reduce the concentration of oxygen in the protected zone and cooling the protected zone.
In the case of protecting certain areas using these systems, it is important to implement all safety measures to protect the people in the protected zone since the concentration of carbon dioxide in the protected zone is lethal.

Nowadays, the usual application of fire suppression systems using this gas is localised protection of individual devices and machinery. For the purpose of complete protection of areas other gaseous fire suppression systems have been developed that are not lethal to the people present in the protected zone.