What is one possible hazard of using a carbon dioxide extinguisher in enclosed spaces?

Using a carbon dioxide extinguisher in enclosed spaces presents a significant hazard due to oxygen displacement. Carbon dioxide (CO2) is a non-flammable gas that is effective for extinguishing fires primarily by displacing oxygen, which is necessary for combustion. In a confined environment where the volume of air is limited, the introduction of CO2 can significantly reduce the concentration of oxygen available for breathing.

When oxygen levels drop below safe thresholds, individuals may experience hypoxia, which can lead to unconsciousness or even death in severe cases. This hazard is particularly critical in enclosed areas where there is limited ventilation, as the buildup of CO2 can quickly increase, further exacerbating the risk to anyone present.

In contrast, although increased humidity, the creation of toxic fumes, and overheating of surroundings might seem concerning, they do not represent the same immediate and life-threatening risk associated with oxygen displacement in an enclosed space. Thus, the focus on oxygen displacement highlights a critical safety consideration in fire suppression tactics involving carbon dioxide extinguishers.