A system and method for air bag ventilation

An air-bag module comprising: a container having at least one rigid wall and defining an internal volume; an aperture formed in the rigid wall; a cover which at least substantially covers the aperture in a closed position and substantially prevents the flow of gas through the aperture, wherein the cover may move from the closed position to an open position, in which a gas flow path through the aperture is established, and wherein, in the open position, at least a part of the cover protrudes inwardly into the internal volume.