CO2 FIRE EXTINGUISHER INFORMATION
Carbon dioxide (CO2) extinguishers contain a mixture of liquid and gaseous carbon dioxide (a non-flammable gas). CO2 is normally a gas at room temperature and pressure. Inside the extinguisher, it must be stored under high pressure to make it a liquid. When you release the pressure, the gas expands rapidly and makes a huge white jet.
Carbon Dioxide is heavier than oxygen so it starves the fire of oxygen. It destroys the fire triangle in two other ways: it smothers the oxygen and, when it turns from a liquid back to a gas, it "sucks" in a massive amount of heat from its surroundings (the latent heat of vaporization), which cools whatever you spray it on by removing heat.
CO2, a clean gaseous agent which displaces oxygen. They are suitable for Class B & C fires. They are NOT intended for class A fires, as the high-pressure cloud of gas can scatter burning materials. CO2 is not suitable for use on fires containing their own oxygen source, metals or cooking media. Although it can be rather successful on a person on fire, its use should be avoided where possible as it can cause frostbite and suffocation.