Oxygen toxicity can become problematic when breathing compressed air greater than _____ ATA partial pressure.

Oxygen toxicity is a condition that can occur when a diver breathes oxygen at elevated partial pressures, which can happen when diving deeper than certain depths. The correct threshold for the partial pressure of oxygen, which is approximately 1.6 ATA, is significant because it marks the point at which the risk of central nervous system oxygen toxicity begins to increase.

At partial pressures greater than 1.6 ATA, divers are at a higher risk for symptoms such as visual changes, seizures, and in severe cases, loss of consciousness, which can be particularly dangerous underwater. This knowledge is crucial for divers, especially when planning dives that utilize enriched air or when diving at depths where the partial pressure of oxygen can exceed 1.6 ATA. Understanding this limit allows divers to implement safety protocols and avoid exposure that could lead to toxicity.

In contrast, partial pressures less than 1.6 ATA, such as 1.0 or 2.0 ATA, do not pose the same level of risk for acute toxicity, making it important for divers to be aware of their depth and the breathing gas mixture they are using.