Abstract: An impact extruded perforated aluminum housing contains a two-stage gas generator having a perforated bulkhead positioned between the stages. Each stage includes a combustion chamber having an igniter and pyrotechnic charge therein with cooling and filter screens surrounding the combustion chamber. The igniter of the first stage is fired by a squib responsively to an external electrical signal. A rupturable barrier and a ball valve associated with the bulkhead control the flow of gas through the bulkhead and provide mechanical timing for ignition delay in the firing of the second stage after the first stage has been fired, and also provide pressure control after ignition of both stages to prevent repressurizing the first stage. A rupturable foil barrier surrounding the combustion chamber in the first stage promotes a rapid rise in pressure therein and thus breakout sooner therefrom of gas to an airbag to be inflated.