Why is it important to identify the maximum operating depth of the decompression gas?

Identifying the maximum operating depth of the decompression gas is crucial to prevent central nervous system oxygen toxicity because different gas mixtures have specific maximum depths at which they can be safely used. When diving with mixtures that contain higher percentages of oxygen, such as nitrox, the risk of oxygen toxicity increases with depth due to the partial pressure of oxygen rising. If the diver exceeds the maximum operating depth for that gas, the partial pressure of oxygen may reach levels that could lead to serious physiological effects, including seizures or other life-threatening conditions. Therefore, understanding the maximum operating depth helps ensure that divers remain within safe limits, mitigating the risk of oxygen toxicity during their dives.