At what depth does the maximum operating depth for EAN36 become a concern?

The maximum operating depth for EAN36 (Enriched Air Nitrox with 36% oxygen) becomes a concern at depths of around 30-32 meters (100-105 feet) due to the physiological effects of increased partial pressure of oxygen. At this depth, the partial pressure of oxygen in the breathing gas significantly increases, which in turn raises the risk of oxygen toxicity, particularly during prolonged exposure.

Oxygen toxicity can lead to central nervous system effects, such as dizziness, visual disturbances, and in severe cases, seizures, which can be dangerous while diving. This risk makes it critical for divers to be aware of the maximum operating depth for their specific gas mixtures to ensure safe diving practices.

The depth range in the other choices either falls below or significantly exceeds the levels at which these risks start to become a primary concern for EAN36.