What percentage of oxygen in the air can lead to the onset of hypoxia symptoms?

The onset of hypoxia symptoms typically occurs when the percentage of oxygen in the air falls below a certain threshold. In a normal atmospheric environment, the air contains approximately 21% oxygen. When the oxygen concentration is reduced to around 14%, individuals may start to experience signs of hypoxia, which can include symptoms such as difficulty breathing, altered mental status, and decreased physical performance. This particular threshold is critical for divers and individuals operating at altitude, as maintaining proper oxygen levels is essential for safety and overall health.

Understanding the significance of oxygen levels is vital for SCUBA divers and other individuals in high-risk environments. Hypoxia can impair cognitive and physical capabilities, significantly increasing the risks associated with diving. Hence, awareness of these levels and the corresponding effects is essential for effective dive supervision and safety precautions.