A pyrotechnic composition containing oxidizing agents, nanocarbon and nanoaluminum additives is developed in the course of the investigation reported. The burning rate of the composition containing 80 % of ammonium nitrate, 5 % of nanoaluminum and 15 % of nanocarbon meets the requirements of a chemical gas-generating composition. It is found equal to 1.25 mm/s. The flash point of nanoaluminum amounts to 750°C, while that of the nanocarbon fuel is equal to 350°C. The laws which determine the burning of the pyrotechnic composition as a function of the nanoaluminum content are investigated. The novelty of the gas-generating composition developed in this work lies in a new mechanism of decomposition of the ammonium nitrate flowing in the confined space. In this case, the aluminum nanopowder is oxidized to aluminum oxide which accelerates the thermal decomposition of ammonium nitrate turning it completely into a gaseous state. [ABSTRACT FROM AUTHOR]