What indicates that a Personal Breathing Equipment (PBE) unit is compliant during the preflight check?

The indication of compliance for a Personal Breathing Equipment (PBE) unit during the preflight check is reflected through the condition of the humidity indicator. When the indicator shows blue, clear, or white, it signifies that the unit is properly sealed and has not been compromised by humidity or other factors that could affect its performance. This is crucial for ensuring that the PBE is ready for use in an emergency situation, where maintaining a breathable atmosphere is vital for crew and passenger safety.

In contrast, a red humidity indicator suggests that the unit may have been activated or exposed to conditions that could degrade its effectiveness. Additionally, if the seals are broken or the unit is not secured, these indicate potential issues that could lead to failure in emergency use. Proper checks are essential for confirming that the PBE can function as intended when needed.