Carbon Dioxide Fire Extinguisher
What Does Carbon Dioxide Fire Extinguisher Mean?
A carbon dioxide (CO2) fire extinguisher is a portable, active fire protection device that works by expelling carbon dioxide onto a fire. It works by displacing the oxygen the fire relies upon to continue burning, and it is primarily used to extinguish fires in which the source of the fuel is a flammable liquid or gas.
Carbon dioxide fire extinguishers are a very common form of fire extinguisher and are used in situations where traditional water and foam fire extinguishers or dry chemical fire extinguishers are not suitable. A carbon dioxide fire extinguisher is a “clean extinguisher” and leaves no residue on the area it is applied.
Carbon Dioxide Fire Extinguisher
The type of fire suppressant that needs to be used to extinguish a particular workplace fire varies depending on the substance that is fueling the fire, as well as the equipment and human safety considerations that exist within the vicinity of the fire.
For instance, traditional water extinguishers are useful for extinguishing ordinary combustion fires (Class A fires) by eliminating the heat necessary for the fire to continue; however, they are not effective for situations in which the source of the fire is a liquid (Class B) or gas. The reaction may inadvertently cause the flaming liquid to displace or splash, and water may not be able to reduce the heat from the fire to a low-enough temperature to terminate the combustion reaction that keeps the fire burning. In this case, a carbon dioxide extinguisher can be used to eliminate the fire by displacing the oxygen that the fire relies upon for fuel.
Because carbon dioxide is a non-conductive material, CO2 extinguishers are also useful for extinguishing electrical (Class C) fires and were originally developed for this purpose. They are not useful as a method of extinguishing ordinary flammable combustible solids, as the solid will continue to smolder after being extinguished and may reignite once oxygen returns to its immediate atmosphere.
A dry chemical fire extinguisher can be used to eliminate all of the types of fire that a carbon dioxide extinguisher can, as well as additional fire types such as Class A fires; however, a carbon dioxide extinguisher may be better-suited for the elimination of a Class B or C fire, as dry chemical extinguishers release a toxic substance that is easily inhaled if used in an enclosed space without adequate respiratory protection.
CO2 fire extinguisher uses:
• Fires involving equipment such as computers, or generators (‘electrical’ fires)
• Fires involving some flammable liquids, such as petrol, diesel, and paint (‘class B’ fires)
Do not use CO2 extinguishers for:
• Cooking fires involving oil and grease, such as chip pan fires (‘class F’ fires)
How to identify a CO2 extinguisher:
• BLACK coloured label stating ‘CO2’
• The nozzle ends in a distinctive black ‘horn’
• Should be identified by an extinguisher ID sign fixed nearby – ‘CO2 Extinguisher’
How CO2 fire extinguishers work:
CO2 fire extinguishers discharge CO2 gas, also known as carbon dioxide. This is stored in the extinguisher as a liquid, and the gas is created under pressure when the handle of the extinguisher is squeezed.
This causes the CO2 gas to emerge at great speed, which is why CO2 fire extinguishers are not recommended for chip pan fires – they could literally blast the flames into surrounding areas.
Unlike water and foam extinguishers, CO2 fire extinguishers do not work by cooling the fire and so are ineffective on fires involving flammable solids.
Instead, CO2 extinguisher work by replacing the oxygen surrounding the flames with carbon dioxide, meaning the fire can no longer burn.
Pros and Cons of CO2 extinguishers:
Pros: extremely effective on electrical fires; do not leave any residue behind when they are used.
Cons: 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. See the following link for a full article explaining the correct use of fire extinguishers in confined spaces.
Use of CO2 Extinguishers
CO2 fire extinguishers were originally developed to deal with liquid fires such as burning petrol. The inert CO2 gas excludes oxygen from the surface of the liquid fire and stops the fire. These days CO2 fire extinguishers are mainly used on electrical fires in modern offices, as the CO2 does not leave any residue and does not damage computers, although the cold temperature and the electrostatic shock from the CO2 gas can damage very sensitive electronic equipment.
We offer installation and commissioning of your CO2 extinguishers as well. Our BAFE certified engineers will visit you to do all the work. We also offer the servicing of all your extinguishers.