Which factor must divers monitor to ensure safe Nitrox usage?

Monitoring oxygen exposure limits is crucial for divers using Nitrox because it directly relates to the physiological impact of increased oxygen concentrations at depth. Nitrox blends typically contain a higher percentage of oxygen than standard air, which can heighten the risk of oxygen toxicity. This toxicity can lead to serious health issues, including seizures and other complications if the body is exposed to elevated levels of oxygen for prolonged periods or at greater depths.

To prevent these risks, divers must be aware of their maximum allowable exposure limits, which are determined by the percentage of oxygen in their breathing gas and the depth of their dive. By adhering to these exposure limits and using dive tables or computers designed for Nitrox, divers can significantly reduce the risk of oxygen toxicity during their dives.

While the other factors, such as water temperature, current dive conditions, and equipment wear and tear, are important for overall dive safety and planning, they don't specifically address the unique risks associated with oxygen exposure that are critical for safe Nitrox use.