CO2 Fire Extinguishers

What is a CO2 Fire Extinguisher?

A CO2 fire extinguisher is specifically designed to extinguish fires fuelled by flammable liquids (class B) and live electrical equipment. It discharges carbon dioxide which displaces oxygen and suffocates the fire. CO2 fire extinguishers can be identified by their black label, and are usually found in industrial settings such as laboratories, commercial kitchens, and places with electrical equipment.

CO2 fire extinguishers can be by the black identification field with the words CO2 or 'Carbon Dioxide' printed on this black field. CO2 extinguishers also have no pressure gauge and a discharge horn rather than a hose. You can often find them paired with a water fire extinguisher in many settings to cover multiple fire risks.

What can a CO2 fire extinguisher be used on?

CO2 extinguishers can be used on:

• Fires involving electrical equipment such as servers or generators
• Class B fires - fires involving flammable liquids such as paint or fuel

CO2 fire extinguishers are usually selected for their ability to fight 'electrical fires'. Often found in areas where there is a large amount of electrical equipment like servers or generators, CO2 extinguishers usually cause less damage to electrical equipment when discharged as they leave no residue.

CO2 fire extinguishers are often paired with a water or foam extinguisher in office or retail environments. CO2 extinguishers are not suitable for use on class A (solid combustible) fires as they do not cool the fire and so are not effective on flammable solids such as wood, plastic or fabric. When paired with water or foam extinguishers, CO2 can be used to tackle electrical fires, and water or foam can be used to tackle class A fires. This pairing is designed to cover most common fire risks found in this type of environment.

CO2 fire extinguishers can also be used on class B fires (fires involving flammable liquids such as petrol or paint). CO2 extinguishers discharge a gas rather than a liquid and so can extinguish fires involving liquids without spreading the fire further.

What size CO2 fire extinguisher do I need?

CO2 extinguishers are available in a smaller size (2kg) or a larger size (5kg). 2kg CO2 fire extinguishers are often used in offices, schools or retail environments to tackle smaller fires involving electrical equipment. The 2kg extinguishers are lighter and therefore easier to handle.

The larger 5kg CO2 fire extinguisher is often used in more industrial environments or in a premises with a larger amount of electrical equipment. Server rooms or plant rooms with high voltage equipment commonly use this larger size of CO2 fire extinguisher.