CO2 Fire Extinguishers
CO2 (carbon dioxide) fire extinguishers use pressurized carbon dioxide gas, which is released as a heavy, freezing cloud that displaces oxygen and rapidly cools the fuel source. The primary advantage of CO2 extinguishers is that the agent is a gas, making it non-conductive and leaving no residue when it dissipates.
CO2 fire extinguishers are rated for the following classes of fire:
- Class B (flammable liquids). Effective on fires involving flammable liquids such as grease, oils, gasoline, and solvents.
- Class C (energized electrical equipment). Safe for use on live electrical equipment, since it doesn’t conduct electricity.
Common Usage Situations
CO2 fire extinguishers are selected for environments containing sensitive electrical equipment or where cleanup must be minimized:
- Electrical switch rooms and equipment closets. Ideal for localized fires in control panels, circuit breakers, and other enclosed electrical spaces.
- Laboratories and manufacturing floors. Used near machinery and equipment that could be damaged by water or corrosive dry chemical powders.
- Computer and server areas. While clean agents are often preferred for larger rooms, CO2 is a common choice for smaller computer banks and electronics due to its lack of residue.
It’s important to note that CO2 extinguishers are generally not effective on deep-seated Class A fires (ordinary combustibles) because the gas dissipates quickly, allowing the hot materials to reignite.