What visual sign indicates that PBE is running out of oxygen?

• A. Steady green light
• B. Green and red flashing light
• C. Blue flashing light
• D. No lights at all

Answer: (B)

The correct answer is indicated by a green and red flashing light. This specific visual signal is designed to alert users that the Portable Breathing Equipment (PBE) is nearing the end of its oxygen supply.

In the context of emergency equipment, such signals serve a critical function. The combination of green and red not only signals that the PBE is operational but also warns that the oxygen levels are depleting, signaling the need for the user to take appropriate action, such as locating a fresh supply or exiting the situation if safe to do so.

Understanding the function of these signals is essential for emergency preparedness, ensuring that personnel can respond effectively when faced with potentially dangerous environments that require the use of breathing apparatuses.