How can a diver effectively manage the risks of CNS oxygen toxicity?

Limiting the partial pressure of oxygen (ppO2) to 1.40 during the bottom stage is an effective strategy for managing the risks associated with central nervous system (CNS) oxygen toxicity. CNS toxicity can occur when the ppO2 exceeds certain levels, particularly during prolonged exposure. Keeping the ppO2 at or below this limit helps to mitigate the risk of seizures and other neurological symptoms that can arise from excessive oxygen levels.

In decompression diving, particularly when using a mixed gas or trimix, controlling the ppO2 is crucial because it directly affects both safety and performance. Maintaining a ppO2 within recommended limits allows divers to benefit from the advantages of increased oxygen availability during the dive without exceeding safe exposure thresholds.

Other strategies might involve adjusting the dive profile, such as shortening dive duration, but the explicit control of the ppO2 level serves as a primary method to reduce the likelihood of CNS toxicity during specific phases of the dive, making it a foundational component of safe dive planning and execution.