Compressed gas accumulator for a vehicle occupant restraint system and gas bag module

A compressed gas accumulator for a vehicle occupant restraint system comprises an accumulator container in which gas is stored for a long time at high pressure, a pyrotechnical charge, and at least one gas exit port. The exit port is opened by activation of the pyrotechnical charge in response to an activating signal to enable the compressed gas to emerge from the accumulator container. The gas exit port has a flow cross-section and at least one wall at least partly rimming the exit port. At least a portion of the wall is of a material which is attacked by the gas in the course of gas exit by erosion and/or combustion so that the flow cross-section of the gas exit port is increased to a degree which is at least approximately predetermined.