According to the CNS Clock Table, what are the limits for a ppO2 of 1.4 ata?

The CNS Clock Table is used to help divers manage their exposure to oxygen while diving with enriched air nitrox. A partial pressure of oxygen (ppO2) of 1.4 ata is commonly recognized as a safe limit for recreational diving, where the risk of central nervous system (CNS) toxicity begins to increase.

For a ppO2 of 1.4 ata, the maximum exposure time for a single dive is typically established at 150 minutes, providing divers with a clear guideline on how to calculate their safe dive profiles. Furthermore, the cumulative exposure limit over a 24-hour period is set at 180 minutes. This data helps divers understand both single dive limits and overall exposure, which is important for planning multiple dives within a given timeframe.

Understanding these limits is crucial for safety, as exceeding them increases the risk of oxygen toxicity, which can have serious neurological consequences. By adhering to the CNS Clock Table, divers can minimize these risks while taking full advantage of the benefits of diving with enriched air nitrox.