What is the average mix for recreational diving to avoid oxygen toxicity?

The average mix for recreational diving to avoid oxygen toxicity is commonly around EANx mixtures of 32% to 36% oxygen. This range is particularly advantageous as it provides a balance between increasing the amount of oxygen (which allows divers to stay longer at greater depths without experiencing nitrogen narcosis) while still ensuring that the partial pressure of oxygen remains within safe limits to avoid the onset of oxygen toxicity.

When oxygen partial pressures exceed 1.6 ATA (which is commonly reached at depths greater than around 30 meters or 100 feet when using pure oxygen), the risk of oxygen toxicity increases significantly. The mixture of 32% to 36% oxygen keeps the partial pressure within a safer range for most recreational diving activities, thus allowing divers to maximize their time underwater while minimizing risks.

Other options, such as mixtures that contain higher percentages of oxygen or pure oxygen, can lead to a greater risk of toxicity due to the increased partial pressure, particularly at depths where increased ambient pressure is present. Thus, the selection of EANx mixtures within this specified range is a conscientious choice for maintaining safety in recreational dive practices.