Electron spectroscopy for chemical analysis (ESCA) tests indicate that after 2-4 hours of removing a steel panel from a ZERUST VCI package, the surface of the item is completely free of the corrosion preventing molecular layer.
The onset of corrosion on a part is contingent upon the cleanliness of the part and the surrounding environment, including factors such as relative humidity, presence of contaminants or wood, and temperature, etc.