An enriched air diver exceeding an oxygen partial pressure of 1.4 ata runs the risk of which condition?

Diving with enriched air increases the proportion of oxygen in the breathing gas, which can be beneficial for certain applications but also introduces risks when exposure limits are exceeded. When the partial pressure of oxygen exceeds 1.4 atmospheres absolute (ata), it significantly raises the risk of central nervous system (CNS) oxygen toxicity. This condition occurs when higher concentrations of oxygen lead to neurological effects due to excessive oxygen in the brain, resulting in symptoms such as visual disturbances, muscle twitching, seizures, or, in severe cases, loss of consciousness.

Maintaining the partial pressure of oxygen below this threshold is crucial to minimize the risk of these potentially dangerous effects while diving with enriched air. Understanding the physiological implications of varying gas compositions and pressures is vital for safe diving practices, especially when using mixtures containing elevated levels of oxygen.