How to use a CO2 Fire Extinguisher

How to use a CO2 Fire Extinguisher

CO2 extinguishers used on class B and electrical fires. They are used on electrical equipment in case of high or low voltage. It is also highly effective against liquid flammables such as propane, solvents, petrol, and butane.


Why is CO2 used as a fire extinguisher?


Firstly, it starves the fire of oxygen. It is also cold as it comes out of fire extinguisher so it cools the fuel quickly. It may be ineffective on class A fires due to the fact it may not displace enough oxygen to put the fire out. Class A may also smolder and re-ignite.


How do you identify a CO2 Extinguisher?


It is manufactured to BS EN 3 and must have a red body with a black band encompassing 5-10% of its surface area.


We can quickly identify because of its black label seen in the images on the left and above. The text at the top of the extinguisher reads “Carbon Dioxide”.


Older CO2 extinguishers have an entire black body. These do not comply with British standards and should be replaced and disposed of in an environmentally friendly manner.


What class is a CO2 fire extinguisher?


It extinguishes the fire by taking away the oxygen element of the fire triangle along with the removal of heat with its cold discharge. It is used on class B and C fires.


Using a CO2 fire extinguisher


The extinguisher has a swivel horn, which should not be helped when discharging the extinguisher because as the CO2 released ice rapidly, forms on the horn and as a result your skin may get frozen or burnt.


How do carbon dioxide fire extinguishers work?


It has carbon dioxide in the form of liquid and as it is let off. When the liquid released into the air neutralising the oxygen that fire is feeding on, disabling the fire's ability to spread.


It is used as an alternative to water for most of the fires.


How to use?


1. Before attempting to fight the fire, check whether it is totally charged and safety pin is not bent

2. Don’t hold the horn as it becomes cold during use and thus it leads to severe frost burns

3. Squeeze the lever slowly to start discharging the extinguisher, as the fire begin to lessen carefully move closer to it

4. Standing a safe distance from fire and remove the safety pin, it will break the tamper seal

5. Aiming the extinguisher

6. Electrical equipment – with the power off, direct the hose straight

7. Flammable liquids – aim the horn at base of fire and move across the area

8. Make sure that fire is fully extinguished, if not re-ignition is highly likely


Veteran fire safety recognises the importance of fire safety, selling wide a range of extinguishers. See them here -


Although we always suggest some Fire Extinguisher training before using a Fire Extinguisher.