At what percentage of oxygen can people experience disorientation and irrational thinking while escaping a fire?

The correct choice indicates that people can experience disorientation and irrational thinking at an oxygen level of 17%. In terms of human physiology, normal ambient air contains approximately 21% oxygen, which is optimal for sustaining cognitive functions and physiological processes. As the percentage of oxygen decreases, cognitive functions begin to deteriorate.

When oxygen levels drop to around 17%, the brain does not receive enough oxygen to function properly, which can lead to confusion, disorientation, and impaired judgment. This is particularly critical in situations such as escaping a fire, where quick decision-making is essential for safety. This understanding highlights the importance of maintaining adequate oxygen levels, especially in emergency scenarios where breathing may be compromised by smoke and toxic gases.

In this context, the lower oxygen levels directly correlate with increasing cognitive impairment, emphasizing the serious risks associated with low oxygen environments during emergencies.