How to Use a CO2 Fire Extinguisher

CO2 fire extinguishers are mainly aimed at electrical fires but are also suitable for Class B liquid fires and are used in different ways depending on the type of fire they are being used on. Do not use CO2 extinguishers in small rooms as CO2 gas is poisonous at only 4% concentration and can kill at just 8%.

Only tackle small fires with an extinguisher. If the fire has taken hold do not fight the fire but evacuate immediately and warn others of the fire, then call the fire and rescue service. If you tackle the fire make sure you stay at a safe distance and follow the instructions below.

1. Pull the safety pin (Fig.2), this will break the tamper seal
2. Do not hold the horn, unless it is a frost-free horn, as it becomes extremely cold during use and can lead to severe frost burns. Only purchase CO2 extinguishers with frost-free horn to prevent this happening. 
3. Squeeze the lever to start discharging the extinguisher. Please note that the CO2 extinguishers make a very strong discharge noise, which is normal.
4. Aiming the extinguisher:
   • Flammable liquids: Aim the horn at the base of the fire and move across the area. Be careful not to splash the burning liquid with the powerful jet of the CO2 extinguisher.
   • Electrical equipment: Switch off the power, where safely possible, to prevent later re-ignition and then direct the horn straight at the fire
5. Please note that a CO2 extinguisher only has a very short discharge time.
6. Ensure all the fire has been extinguished as re-ignition is easily possible when a CO2 extinguisher has been used. CO2 gas drifts off after use and if the fire is still very hot it might just re-ignite.

Reviewed: 20/09/2019 (doc:18 V2.0). 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.