In what situations should EANx dives be avoided?

Dives involving deep depths and high exertion should be avoided when using EANx (Enriched Air Nitrox) because these conditions increase the risk of oxygen toxicity. Oxygen toxicity is a concern when the partial pressure of oxygen in the breathing gas exceeds safe levels, which is more likely at greater depths due to the increased pressure on the body.

When divers are at greater depths, the amount of nitrogen they are absorbing also increases, which can complicate dive planning and risk assessments. High exertion further exacerbates this issue, as it leads to a higher metabolic rate and increased oxygen consumption, raising the partial pressure of oxygen beyond safe limits.

In contrast, shallow dives may allow for safer use of EANx since the partial pressures of gases are lower, reducing the risk of toxicity. Recreational dives and night dives can often be conducted safely with proper planning and understanding of the gas mix and conditions, making this option unsuitable as a general restriction for EANx dives.