What is the maximum partial pressure of oxygen (PPO2) for recreational divers?

The maximum partial pressure of oxygen (PPO2) for recreational divers is set at 1.4 ATA. This limit is critical because it helps to prevent the risks associated with oxygen toxicity, which can occur at elevated PPO2 levels.

Oxygen toxicity mainly affects the central nervous system and can lead to serious health issues such as seizures, which can be dangerous underwater. The recreational diving community and organizations like PADI and NAUI base their guidelines on extensive research regarding safe exposure limits to oxygen.

By maintaining a PPO2 of 1.4 ATA or lower during dives, divers can enjoy the benefits of enriched air nitrox while minimizing the risks involved with higher oxygen levels. This approach helps in extending the bottom time and reducing the likelihood of decompression sickness without significantly increasing health risks.