What does the term "Partial Pressure of Oxygen" (PPO2) refer to?

The term "Partial Pressure of Oxygen" (PPO2) specifically refers to the pressure exerted by oxygen in a gas mixture. In any gas mixture, each component gas contributes to the total pressure, and the partial pressure is a measure of the specific pressure that one type of gas (in this case, oxygen) exerts independently from the other gases present.

Understanding PPO2 is crucial for divers using Nitrox because it directly influences oxygen toxicity and the effects on the body during dives at different depths. For instance, as a diver descends, the total pressure increases which also increases the partial pressure of oxygen that the diver is exposed to. Therefore, monitoring and managing PPO2 is vital for safe diving practices with enriched air mixtures.

Other choices, while related to gases in mixtures, pertain to different aspects of gas behaviors or specific components not relevant to the definition of PPO2.