What determines the required air supply time of an SCBA?

The required air supply time of an SCBA is fundamentally influenced by factors such as the physical load being carried, the user's activity level, and the size of the cylinder. When a user engages in more strenuous activities, their oxygen consumption increases, leading to a faster depletion of the air supply. Likewise, the size of the cylinder directly impacts how long the air will last; larger cylinders typically provide more air than smaller ones. Thus, understanding these elements is crucial for ensuring that the user has adequate air for the duration of their operations in hazardous environments. This comprehensive approach allows users to effectively gauge how long they can safely operate while wearing an SCBA, making the understanding of physical load, activity, and cylinder size vital for safe practices.