What does "ppO2" stand for in diving terminology?

The term "ppO2" stands for "partial pressure of oxygen." In diving, understanding the partial pressures of different gases is crucial for safe diving practices, particularly when using enriched air nitrox. The partial pressure of oxygen refers to the pressure exerted by oxygen in a mixture of gases, such as the air we breathe or the nitrox used during diving.

This measurement is significant because it helps divers determine the safe operating limits for various gas mixtures at different depths. As a diver descends, the total pressure increases, and consequently, the partial pressure of oxygen also increases. If the partial pressure of oxygen exceeds certain levels, it can lead to toxicity and other dangerous physiological effects. Therefore, monitoring ppO2 is essential for managing dive safety and ensuring that divers stay within safe operational limits. This is particularly important when diving with enriched air nitrox, where the oxygen content is higher than standard air, requiring careful consideration of the ppO2 to avoid complications such as oxygen toxicity.