What does alternating flashing yellow lights indicate regarding the SCBA air cylinder?

The indication of alternating flashing yellow lights on the SCBA air cylinder signifies that the air supply has fallen below a critical threshold, specifically less than one-third of its full capacity. This warning is crucial for the safety of the user, as it alerts them that they need to take action, such as exiting the hazardous environment or preparing to switch to a secondary air source. Understanding this signal helps ensure that the user maintains a sufficient air supply while operating in potentially dangerous or oxygen-deficient environments. Recognizing these indicators promptly can be the difference between safety and risk during emergency operations.