Battery rooms ventilation and proper upkeep

The UK P&I Club has issued Technical Bulletin No.41 regarding battery rooms ventilation and proper upkeep. Closing devices on battery room ventilators should be left in an open position and should only be closed in an emergency situation. The Club would remind Member's of the MSC circular MSC.1/Circ.1434 issued in June 2012 dealing with the ventilation arrangements of ship's battery rooms. The circular states that when battery room ventilators are fitted with a closing device, these devices should be left in an open position and a clear warning notice fitted to prevent the possibility of inadvertent closing: The closing device should only be closed in an emergency situation. If battery room compartment ventilation is inadequate, or the ventilation is restricted for a period of time, there is a risk of a build up of combustible hydrogen gas .

The ISPS code and the ship security plans require the battery rooms to be locked or tagged shut. This should not include the ventilator to the battery compartments. (Safety takes priority over security)
For more information, click at UK P&I Club Technical Bulletin No.41

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.