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Fire Safety for Facilities Management Personnel – Fire extinguishing appliances – Part 221

October 2, 2023 11:22 am

Lawrence Webster Forrest (LWF) is a specialist fire engineering and fire risk management consultancy whose aim is to give information on best practice in fire safety for facilities management personnel through this blog series. In part 220, LWF talked about powder fire extinguishers and their usage. In part 221, we discuss carbon dioxide fire extinguishers.

Carbon dioxide fire extinguishers work by displacing the oxygen needed by the fire to burn and also, cooling the flames because the carbon dioxide is very cold when it leaves the extinguisher canister.

Most carbon dioxide extinguishers are available in 2kg or 5kg of the agent, but as the gas is stored as a liquid under high pressure, the cylinder itself has a high gross weight of between 5kg and 12kg.

It would not be usual to provide a carbon dioxide extinguisher for every day first-aid firefighting because they have a lesser performance against fire when compared to other types of extinguisher at a similar gross weight. They are commonly seen, however, in areas where electrical equipment fires are possible.

A carbon dioxide extinguisher should not be discharged in confined spaces as the gas is an asphyxiate and toxic to people or animals. However, the relatively small amount in a portable extinguisher means that it will be safe to use in most areas of commercial and industrial buildings and offices.

The extinguishers are not particularly user-friendly. The overall weight of the cylinder is high and when compared to their extinguishing capacity, other options are often preferred. They make a significant amount of noise when triggered and the discharge horn becomes very cold during discharge. Indeed, if it is gripped tightly for a long period, frostbite may even result.

If any staff are expected to use a carbon dioxide extinguisher, it is important that they are trained in its use, which means they will expect the noise it will make, understand how to hold it correctly to avoid damage to the hands etc.  It should also be noted that the person operating the cylinder will have to be in close proximity to the fire, as the effective discharge distance is only around 1 metre.

In part 222 of this series, LWF will look at some of the other agents used in fire extinguishers both currently and in past years. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact LWF on freephone 0800 410 1130.

Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 35 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.


While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.


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