What are the two vital pieces of information displayed on a Nitrox fill tag or label?

The critical pieces of information displayed on a Nitrox fill tag or label are the fraction of oxygen (FO2) in the gas mixture and the maximum operating depth (MOD) associated with that specific gas blend. FO2 provides divers with essential information about the proportion of oxygen in the mix, which is critical for managing exposure to the gas and mitigating the risk of oxygen toxicity. It informs the diver about how the gas behaves at different depths.

MOD indicates the maximum depth at which the gas mixture can be safely used based on its oxygen content. Understanding this information is vital for dive planning, as it helps divers stay within safe limits and avoid dangerous situations associated with breathing nitrogen-rich air or encountering high partial pressures of oxygen.

While pressure and temperature are important for understanding how gas behaves under different conditions, they do not specifically relate to the safe utilization of Nitrox blends. Similarly, knowing the mixture and tank size is pertinent but does not provide the critical safety parameters of if and how deep a diver can safely operate with that specific gas. Thus, focusing on FO2 and MOD ensures that divers have the necessary knowledge to dive safely with Nitrox blends.