Which of the following scenarios might increase the risk of CNS toxicity?

Diving with a partial pressure of oxygen (ppO2) of 1.6 bar or higher significantly increases the risk of central nervous system (CNS) toxicity. This is because the risk of oxygen toxicity is closely tied to the partial pressure of oxygen that a diver is exposed to; as the ppO2 increases, so does the potential for neurological effects.

At 1.6 bar, the oxygen becomes more reactive within the body, leading to an increased chance of convulsions, visual disturbances, and other neurological symptoms. The safe limits for ppO2 during recreational diving are typically 1.4 bar, with 1.6 bar often considered a threshold for caution. Exceeding this level means the diver is at a significantly heightened risk for CNS toxicity, particularly during deeper dives or when exposed to high oxygen concentrations for extended periods.

Understanding how partial pressure affects oxygen toxicity is crucial for safe diving practices, as divers must manage their oxygen exposure to mitigate these risks effectively.