Special attention should be drawn to crew and officers in tankers when dealing with volatile cargos or non-volatile cargos near flashpoint or above it. In such cases it is suggested as best practice to close all external accommodation openings, including putting the air-condition unit in recirculation mode, to avoid the development of flammable atmosphere within a space which normally contains ignition sources. The expected discomfort of crew is balanced by the safety overriding significance.
Despite the aforementioned, closing battery room ventilators openings shall lead, due to ignorance, to an alike end, which crew should and do try to avoid. Consequently, they must be expressly warned to bear in mind that the battery room ventilators are excluded from the general closing orders.