What is the recommended maximum operating depth (MOD) for diving with 36% oxygen?

The recommended maximum operating depth (MOD) for diving with 36% oxygen is based on the partial pressure of oxygen that divers can safely encounter during their dives. When using nitrox mixtures, it's critical to manage the exposure to oxygen to avoid toxicity.

For 36% oxygen, the MOD can be calculated using the formula: MOD = (Partial Pressure of Oxygen / Fraction of Oxygen) - 1. The maximum recommended partial pressure of oxygen for recreational diving is typically considered to be 1.4 ATA (atmospheres absolute).

Using this information, if you set the partial pressure of oxygen to 1.4 ATA and the fraction of oxygen to 0.36, you can calculate the MOD. When you do the math, you find that the MOD for 36% oxygen falls around 30 meters (100 feet). This depth aligns with recreational diving limits and helps to ensure the safety of divers when using enriched air nitrox.

At depths greater than this MOD, the partial pressure of oxygen would exceed safe levels, increasing the risk of oxygen toxicity, which can lead to serious health issues during and after the dive. Thus, adhering to the MOD is critical for maintaining safety while diving with enriched air nitrox.