Which of the following is a crucial factor to consider when planning a dive with enriched air nitrox?

When planning a dive with enriched air nitrox, understanding the partial pressure of oxygen (ppO2) and the exposure duration is critical. Enriched air nitrox has a higher percentage of oxygen compared to standard air, which can provide benefits such as extended bottom time and reduced nitrogen absorption. However, it also introduces the risk of oxygen toxicity if the ppO2 exceeds safe limits, typically around 1.4 ATA for recreational diving.

By calculating ppO2, divers can ensure that their exposure to high levels of oxygen remains within safe limits based on the depth of the dive and the percentage of oxygen in the nitrox mix being used. Additionally, exposure duration can influence the risk of oxygen toxicity—dive plans need to take both factors into account to maintain safety throughout the dive. This careful consideration of ppO2 and exposure helps prevent potential health hazards associated with using enriched air nitrox.

The other factors, while relevant to dive planning, do not directly address the specific concerns related to using enriched air nitrox and managing oxygen exposure.