CO2 fire extinguishers are primarily used for Class B fires (flammable liquids) and electrical fires.
The extinguisher works by displacing oxygen, which suffocates the fire.
It is considered a "clean agent" because it does not leave a residue, making it suitable for use on sensitive electronics and documents.
CO2 extinguishers are typically identified by a black label on the body of the cylinder.
Care should be taken when using a CO2 extinguisher in a confined space as the gas can cause asphyxiation.