What is the recommended maximum operating depth for EAN40?

The recommended maximum operating depth for EAN40, which is a blend of 40% oxygen and 60% nitrogen, is indeed 130 feet. This depth is established considering the effects of increased partial pressures of oxygen at greater depths.

At 130 feet, the partial pressure of oxygen in the mix reaches a level that is generally considered safe for recreational diving, minimizing the risk of oxygen toxicity. In this context, oxygen toxicity can lead to central nervous system effects, which can be dangerous for divers.

Diving deeper than this recommended limit increases the risk of oxygen toxicity significantly, as the partial pressure of oxygen increases with depth. Therefore, sticking to the recommended operating depth helps ensure divers remain within safe limits while enjoying the benefits that enriched air provides, such as reduced nitrogen absorption and longer no-decompression limits.