The rate of combustion of an electrically operated propellant having a self-sustaining threshold of at least 1,000 psi is controlled to produce chamber pressures that are sufficient to produce a desired pressure profile in the airbag to accommodate a range of human factors and crash conditions yet never exceeding the self-sustaining threshold. The combustion of the propellant is extinguished to control the total pressure impulse delivered to the airbag. Propellants formed with an ionic perchlorate-based oxidizer have demonstrated thresholds in excess of 1,500 psi and higher.