What is the recommended maximum partial pressure of oxygen (PO2) for enriched air nitrox diving?

The recommended maximum partial pressure of oxygen (PO2) for enriched air nitrox diving is 1.4 ata. This value is established to manage the risk of oxygen toxicity, which can occur when divers are exposed to elevated levels of oxygen for extended periods.

At a partial pressure of 1.4 ata, divers can safely perform their dive profiles while still having a margin of safety against oxygen toxicity. This maximizes the benefits of diving with enriched air nitrox, such as reduced nitrogen absorption and extended bottom time at certain depths, while minimizing health hazards associated with higher concentrations of oxygen.

Diving with a partial pressure above this limit, such as 1.6 ata or higher, increases the risk of experiencing toxic effects related to oxygen. Therefore, adhering to the 1.4 ata guideline is crucial for ensuring a safe diving experience.