An apparatus for inflating a vehicle occupant restraint includes containing means for receiving gases to provide a combustible mixture of the gases. An igniter is activated to effect ignition of the mixture of gases in response to sudden vehicle deceleration. A directing means directs a flow of gas from the containing means into the inflatable occupant restraint. In the preferred embodiment the gases are an inert gas, a fuel gas, and an oxidizer gas. Also, a lean mixture of a fuel gas and oxidizer gas could be used. An improved igniter transmits energy through an imperforate portion of a wall of the containing means to ignite a charge in the containing means. The igniter may include an elongate core disposed in a frangible sheath which is shattered as the core is burned.