At what oxygen concentration does brain damage begin to occur?

The correct choice indicates that brain damage begins to occur at an oxygen concentration of 10.6%. Human brains are highly sensitive to oxygen levels, and it has been established that prolonged exposure to low oxygen conditions can lead to irreversible damage.

At 10.6% oxygen concentration, there is a significant reduction in the oxygen available for cellular functions, which can lead to hypoxia, a state where the brain does not receive enough oxygen to maintain normal function. This level of oxygen is dangerously low compared to the normal atmospheric concentration of approximately 21%.

Understanding the specific oxygen concentration threshold is crucial for both life safety and health training, especially in environments potentially lacking adequate oxygen, such as in firefighting or confined space operations, where rescuers may need to take preventive actions to avoid dangerous conditions. This knowledge emphasizes the importance of safety protocols and monitoring oxygen levels in such scenarios.