What must vessel personnel verify before commencing vapor control operations?

Before commencing vapor control operations, it is crucial for vessel personnel to verify that the oxygen content does not exceed 8 percent by volume. This is because maintaining low oxygen levels is essential to prevent the risk of fire or explosion when handling flammable liquids. If the oxygen concentration is too high, it can create an environment that is highly conducive to combustion, posing significant dangers to both personnel and the vessel.

Monitoring the oxygen levels helps ensure a safe working environment and is a standard safety procedure in vapor control operations, which are designed to manage the emission of vapors during loading and unloading of liquid cargoes. The focus on managing vapor releases is essential for compliance with safety and environmental regulations.

Other considerations, such as tank temperature, cargo status, and stability, are also important in the broader context of safe operations but are not as critical as the need to control oxygen levels when specifically preparing for vapor control operations.