What is considered a "high" PPO2 in recreational diving?

In recreational diving, a partial pressure of oxygen (PPO2) of 1.4 ATA is generally considered a threshold for safe diving practices. At this level, it allows divers to maximize the benefits of increased oxygen exposure without significantly increasing the risk of oxygen toxicity. For most recreational divers, especially those using nitrox mixtures, a PPO2 of 1.4 ATA is a widely accepted safety standard.

Going beyond this, at 1.6 ATA, there is an elevated risk of oxygen toxicity, which can manifest in various symptoms such as visual disturbances, twitching, or more severe consequences in extreme cases. While diving at 1.0 ATA or 1.2 ATA may be safe, they do not represent the upper limits that divers can typically work within, making 1.4 ATA the practical choice in a recreational context. Understanding these PPO2 levels is essential for divers to ensure both safety and enjoyment during their diving activities.