Why is it important to understand how gas fractions remain constant in terms of safety?

Understanding how gas fractions remain constant is crucial for minimizing the risk of hyperoxia, particularly when using enriched air (Nitrox) in diving. Hyperoxia occurs when there is an excessive amount of oxygen in the body, leading to potential toxicity. As divers use mixed gases, including Nitrox, it is important to know that while the total gas pressure changes with depth, the fractions of each gas in a mixture, including oxygen, remain constant.

This concept is pivotal when planning dives, as exceeding certain partial pressure limits of oxygen can lead to harmful physical effects. Knowing how these gas fractions work allows divers to calculate the safe limits for the use of enriched air and to plan their dives accordingly, ensuring they stay within safe exposure limits throughout their dive. This knowledge plays a direct role in ensuring diver safety and effective management of the risks associated with breathing gas mixtures.