Flight personnel must wait how long after exposure to hyperbaric conditions before participating in low pressure flights?

The appropriate waiting time for flight personnel after exposure to hyperbaric conditions before participating in low-pressure flights is indeed 12 hours. This guideline is crucial as it helps to mitigate the risk of decompression sickness, which can occur if a person transitions too quickly from high-pressure environments (like those experienced in hyperbaric chambers) to lower-pressure environments (like those at high altitudes).

During hyperbaric exposure, the body absorbs more nitrogen due to higher pressures, which can create a danger of nitrogen bubbles forming if the pressure is decreased too rapidly. Waiting for 12 hours allows for adequate off-gassing, which is the process by which excess nitrogen is safely eliminated from the body. This timeframe is based on medical and operational safety practices designed to protect flight personnel during and after exposure to hyperbaric conditions.

Although other options suggest longer waiting times, these are unnecessary given the established protocols and current understanding of decompression physiology. Hence, the choice of 12 hours is aligned with standard operational procedures to ensure the safety and health of the personnel involved.