Carbon dioxide (chemical formula CO2) is a versatile industrial material, used, for example, as an inert gas in welding and fire extinguishers. It is colorless and in low concentrations the gas is odorless however, at sufficiently-high concentrations, it has a sharp, acidic odor. Amongst inert gas extinguishing systems, CO2 extinguishing systems have the greatest acceptance worldwide. The particular advantage of the extinguishing agent is that a room „inerted“ in the event of a fire only has to be aired properly after successful extinguishing. CO2 is inexpensive, reliable, electrically non-conductive and is completely without residue – from a single rack to complex spatial solutions. There is still no alternative to CO2 extinguishing systems for protecting mills and hardening basins.