What type of fires is a carbon dioxide extinguisher primarily used for?

A carbon dioxide (CO2) extinguisher is primarily used for electrical and flammable liquid fires due to its unique properties. CO2 works by displacing oxygen in the area of the fire, which effectively suffocates the flames, preventing combustion. This is particularly effective for fires involving electrical equipment because CO2 does not conduct electricity, making it safe to use on live electrical components. Additionally, CO2 is excellent for flammable liquids since it can rapidly cool the fuel source while eliminating the oxygen necessary for the fire to continue burning.

The extinguishing capability of CO2 for other types of fires, such as those involving wood, paper, or cooking oils, is limited. For example, using a CO2 extinguisher on cooking fires—which may involve grease—can sometimes even spread the fire instead of extinguishing it. Understanding the specific applications and limitations of carbon dioxide extinguishers helps ensure proper fire response and safety.