What is the minimum concentration of oxygen required to maintain consciousness at sea level?

To maintain consciousness at sea level, the minimum concentration of oxygen required is approximately 16%. At this level, the human body can receive sufficient oxygen to support basic metabolic functions and sustain consciousness. Below this threshold, individuals may begin to experience symptoms of hypoxia, which can impair cognitive and physical functions.

The air we breathe at sea level normally contains about 21% oxygen, which provides a comfortable margin above the minimum requirement. However, as the percentage of oxygen falls below 16%, the risks of cognitive impairment and decreased performance increase significantly. This is crucial for divers and others working in different environments where oxygen levels can be affected.

Understanding this minimum concentration is essential not only for safety but also for optimizing performance in environments where oxygen levels may be reduced, such as at altitude or in underwater environments with varying gas mixtures.