How long is the maximum allowable exposure time for 1.6 ATA PO2 when diving recreationally?

The maximum allowable exposure time for a partial pressure of oxygen (PO2) at 1.6 ATA during recreational diving is indeed considered to be 45 minutes. This limit is based on the recommendations established for safe diving practices, taking into account the risk of oxygen toxicity, which can increase at higher pressures of oxygen.

When a diver is exposed to a higher concentration of oxygen, such as when using enriched air mixtures like Nitrox, it is essential to monitor the duration of that exposure at increased pressures. Staying within this 45-minute limit allows divers to minimize the likelihood of experiencing symptoms of oxygen toxicity, which can be dangerous and potentially life-threatening.

Understanding these limits is crucial for divers who use enriched air, as it helps ensure their safety during dives and allows them to maximize their recreational diving experience without exceeding safe exposure times.