What is the primary risk when using a CO2 fire extinguisher in an enclosed space?

Using a CO2 fire extinguisher in an enclosed space primarily poses a risk of suffocation. CO2 extinguishers work by displacing oxygen in the environment where they are used. In confined areas, the concentration of carbon dioxide can increase to a level where there is insufficient oxygen available for breathing. This situation can lead to asphyxiation if someone is exposed for too long in a poorly ventilated area.

Fire extinguishers that utilize CO2 are effective for many types of fires, particularly those involving electrical equipment or flammable liquids. However, the risk of not having enough breathable air is a significant safety concern in enclosed environments where ventilation is limited. It's essential to ensure that areas are adequately ventilated when using a CO2 extinguisher to mitigate this risk and to vacate the space if the air quality becomes hazardous.