The use of carbon dioxide as an extinguisher is closely linked to the spread of electrification. It was in particular the Bell Telephone Company that, since 1914, stimulated the search for an electrically non-conductive chemical to extinguish fires on its telephone switchboards.
The Walter Kidde Company developed, for these requirements, the first portable CO 2 extinguisher and in the 1920s automatic systems that used carbon dioxide were already available.
In 1928 the first NFPA standard for carbon dioxide extinguishing systems began to take shape. Colourless, odourless, non-corrosive, electrically non-conductive, carbon dioxide does not participate in combustion reactions and, therefore, if it is poured onto flames, it moves oxygen (and the vapours that can be ignited) away from these thereby extinguishing them.
Released from refrigerated or compressed storage at high pressure, the gas also expands, cools down, strikes the materials involved in the flames and removes their energy, thereby acting on two of the vertices of the fire triangle (even if the main action is to remove comburent from the reaction).
Typically used in closed rooms, these systems can also be employed in open environments, exploiting localised applications and leveraging on the discharge time and the dynamics of carbon dioxide which, denser and heavier by 50% than the surrounding air, can create blankets that flood the protected spaces.
A CO2 system does not cause damage to structures, furnishings or to protected assets and does not leave residues or decomposition products; naturally present in the air, carbon dioxide has no application limitations and costs that may be related to the use of other gaseous extinguishing agents.
CO2 systems have a good gas penetration rate in the areas to be protected and are effective on a wide range of flammable and combustible materials.