Abstract: Gas generative compositions especially useful in inflators for protective passive restraint devices (e.g., motor vehicle air bags, escape slide chutes, lift rafts, and the like) include a nitrogen-containing fuel and an oxidizer selected from copper (II) oxide (CuO), cupric nitrate, basic copper nitrate (Cu(NO.sub.3).sub.2.3Cu(OH.sub.2), strontium nitrate (Sr(NO.sub.3).sub.2) and mixtures thereof. Most preferably the nitrogen-containing fuel is azodicarbonamidine dinitrate (AZODN) and/or 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20). The compositions of the present invention provide high burning rates with acceptable burning rate pressure exponents which allow their operation at lower pressures, thereby resulting in the use of less costly, lower weight, and lower strength materials for design and manufacture of the inflator pressure vessel.