Basket (0) Checkout
CALL OUR TEAM NOW 0800 612 7831 Also FREE from UK mobiles

Guide to Carbon Dioxide Fire Extinguishers (short CO2 extinguishers)

How to fight fire in live electrical equipment without damaging the rest of the piece of equipment and without electrocuting yourself. Our CO2 fire extinguishers are the answer. CO2 extinguishers contain pure, compressed CO2 (carbon dioxide) gas which is discharged through a horn as a strong (and very loud) jet of gas. The CO2, being chemically inert, starves the fire of oxygen and therefore stops the fire. The gas, as it goes from a highly compressed state to surrounding air pressure level, becomes extremely cold and care must be taken not to touch the pipe leading to the horn, as this can lead to freeze burns. CO2 does not leave any traces and there is therefore no cleaning up required after the discharge. CO2 gas is also non-conductive and there is therefore no possibility of electrocution from discharging the CO2 extinguishers on live electrical equipment.

Limitations of CO2 fire extinguishers

You still require different types of extinguishers for the rest of your fire risks, such as carpets, furnishing, paper, wood and so on. Please note also that CO2, despite being non-toxic, is an asphyxiant gas and should therefore not be used in very small, confined spaces. CO2 is also of limited use when used outdoors, as the CO2 gas can be carried away by winds. Even indoors, as soon as the CO2 dissipates, any remaining embers can start re-ignition of the fire. The discharge time of a CO2 fire extinguisher is only 6 seconds, so the extinguisher is used only to fight a fire when it is still restricted to an electric item, such as a computer. Please note that while the CO2 gas does not leave any residue, the CO2 jet can still cause temperature shock and a static electricity shock to very sensitive electronics.

Main application for CO2 Extinguishers

CO2 fire extinguishers are usually installed in offices, including home offices, data centres, server rooms where there is expensive electronic equipment or irreplaceable data. In the past CO2 fire extinguishers were also used on flammable liquid fires (such as petrol spills), however, there are now more efficient solutions available for these types of fires.

Maintenance of a CO2 fire extinguisher

CO2 extinguishers, like most other extinguishers, must be serviced once a year. However, unlike most other extinguisher types, they do not require refilling after 5 years but 10 years instead, which saves costs. At the end of the ten years, they have to be re-furbished, so the replacement of the CO2 fire extinguisher after 10 years is usually recommended.

When CO2 extinguishers are serviced they are weighed to determine whether they still hold the full charge, as CO2 extinguishers do not have a pressure gauge (the pressure is much higher than for other extinguisher types). The service engineer therefore needs very fine, calibrated scales for this purpose.

What Nationwide Fire Extinguishers can offer

NFEX offers 2 kg CO2 Extinguishers and 5 kg CO2 fire extinguishers complete with horns and brackets for wall-hanging. Like all our extinguishers our CO2 units are kitemarked and ready to use. We also provide a 5 year warranty on the extinguishers. We offer complete peace of mind and are happy to answer any questions you might have.

Facts about CO2 fire extinguishers

  • A fire requires 3 elements to burn; heat, fuel and oxygen. CO2 extinguishers work by removing the oxygen from a fire which impedes the combustion triangle.
  • While CO2 extinguishers are capable of extinguishing flammable liquid fires such as petrol and diesel they are mainly used on fires involving live electrical equipment.
  • CO2 extinguishers are the most popular choice for covering the risk of electrical fires.
  • They do not leave any residue when being discharged.
  • The CO2 (carbon dioxide) cannot be heard 'sloshing' inside the extinguisher. This can lead to the mis-perception that the extinguisher is empty. The only way to determine whether the CO2 extinguisher is full or empty is by weighing and comparing the actual weight with the weight recorded at the factory.
  • As the CO2 gas is extremely cold when leaving the heavily pressurised extinguisher cylinder, there is a risk of freeze burn if the user touches the nozzle or pipe. More up to date models have a ‘frost free’ safety horn to prevent this.
  • It can be very dangerous to use a CO2 extinguisher on a cooking fat fire. Their powerful discharge may cause the burning liquid to spread or even cause a fireball.
  • The most commonly available sizes for CO2 extinguishers are 2kg and 5 kg, although larger models are available which range from up to 30kg.
  • Although mainly red, carbon dioxide extinguishers have a black colour code panel to enable quick identification in case of an emergency.

Reviewed: 01/02/2020 (doc:496 V1.0). Our articles are reviewed regularly. However, any changes made to standards or legislation following the review date will not have been considered. Please note that we provide abridged, easy-to-understand guidance. To make detailed decisions about your fire safety provisions, you might require further advice or need to consult the full standards and legislation.


Close close

This site uses cookies to improve your experience and for essential functioning of the site. By continuing to use our site you agree to the use of cookies.

Change your cookie settings at any time by clicking on the button at the bottom of each page. Read more about the cookies we use in our Privacy Policy.

By continuing to browse this site you agree to the use of cookies. Read our privacy policy to learn more.