What color should the humidity dot be on the sealed PBE during a preflight check?

The humidity dot on a sealed Protective Breathing Equipment (PBE) is an important indicator of the equipment's condition and readiness for use. During preflight checks, the humidity dot should be blue. This blue color signifies that the PBE has been properly sealed and that the humidity levels inside the packaging are within acceptable limits. If the dot were to change color, it would indicate that moisture has entered the package, compromising the integrity of the PBE and suggesting that it may not function effectively in an emergency situation.

Colors such as red, green, or yellow would indicate either issues with the seal or that the equipment may not be suitable for use. Therefore, recognizing that the humidity dot must be blue is crucial for ensuring that safety equipment is reliable and ready to provide the necessary support in an emergency.