CO2 Fire Extinguisher: How It Works And Limitations

CO2 fire extinguisher is filled with non-flammable carbon dioxide gas under extreme pressure. It is designed for Class B and C (flammable liquid and electrical) fires only.

How To Identify CO2 Fire Extinguisher

The Carbon Dioxide fire extinguisher can be identified by its color. The Carbon Dioxide fire extinguisher color is expressed thus: Manufactured to BS EN 3, should have a red body (RAL 3000) and a black band encompassing 5-10% of the fire extinguishers surface area.

Carbon Dioxide fire extinguisher size ranges from 5 lbs to 100 lbs or larger. In the larger sizes, the hard horn will be located on the end of a long, flexible hose.


How does a CO2 fire extinguisher work

Carbon Dioxide fire extinguisher works by displacing oxygen from the fire triangle. The carbon dioxide is also very cold as it comes out of the extinguisher, so it cools the fuel as well. CO2 extinguisher may be ineffective at extinguishing Class A fires because they may not be able to displace enough oxygen to successfully put the fire out.

Where you should not use the carbon dioxide fire extinguishers (Limitation):

This extinguisher should not be uses on:

  • Cooking fires involving oil and grease, such as chip pan fires (‘class F’ fires)
  • Should not be used in a confine space as it can displace oxygen leading to asphyxia.


Read AlsoImportance of hydrostatic testing in fire extinguisher cylinders maintenance


Advantages and Disadvantages of carbon dioxide fire extinguishers:


Advantage of carbon dioxide fire extinguisher:

Do not leave any residue behind when they are used.

Disadvantages of carbon dioxide fire extinguisher:

  • Risk of cold burns if the user holds the extinguisher by the horn;
  • Less environmentally friendly than other types of extinguisher;
  • They replace the oxygen in the air with CO2 so risk of asphyxiation if used in confined spaces.


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Author: Ubongeh