What is the primary hazard of unexpected exposure to high oxygen levels while diving with Nitrox?

The primary hazard of unexpected exposure to high oxygen levels while diving with Nitrox is CNS oxygen toxicity. This condition occurs when divers breathe gas mixtures that contain a higher concentration of oxygen than is typically found in air, especially at depths below 30 meters (100 feet). The nervous system can be adversely affected by this increased oxygen pressure, leading to symptoms such as visual disturbances, tinnitus, dizziness, convulsions, and loss of consciousness.

Understanding the potential for CNS oxygen toxicity is crucial for divers using enriched air Nitrox, as it directly relates to the partial pressures of oxygen they are exposed to during their dives. Monitoring depth and oxygen content is essential in managing this risk. While the other hazards listed, such as barotrauma, air embolism, and decompression sickness, are serious concerns in diving, they typically arise from different scenarios and do not specifically relate to the risk posed by elevated oxygen concentrations.