What is the maximum limiting ppO2 for recreational nitrox dives?

The maximum limiting partial pressure of oxygen (ppO2) for recreational nitrox dives is defined as 1.4 ata. This is the level at which divers can operate without significantly increasing their risk of oxygen toxicity during dives, particularly for exposure times typical in recreational diving scenarios.

A partial pressure of 1.4 ata allows for a safe margin when diving with nitrox mixes that contain elevated levels of oxygen. It is widely recognized in diving practices that staying within this limit minimizes the risks associated with increased oxygen concentrations that can lead to toxic effects on the central nervous system.

While some diving organizations may allow slightly higher limits, such as 1.5 ata for short excursions or specific technical diving situations, the standard maximum for general recreational diving is set at 1.4 ata to prioritize safety. Thus, while other options present higher limits, they do not reflect the conservative practices recommended for recreational divers, especially when considering the longer exposures that are typically involved in leisure diving activities.