Abstract: The invention is directed to a nitrogen gas generator comprising a housing having two ends, ignition means at one end of the housing and a gas outflow opening at the other end of the housing, a volume of a filter at the outflow opening, a volume of solid propellant comprising sodium azide, a binder, a coolant and between 1 and 10 wt % of iron (III) oxide. Between the ignition means and the volume of solid propellant an active layer is present. The active layer comprises between 60 and 90 wt % of sodium azide, between 1 and 15 wt % of a binder, between 0.1 and 10 wt % of a coolant and between 5 and 30 wt % of iron (III) oxide. The content of iron (III) oxide in the active layer is higher than the content of iron(III)oxide in the solid propellant.