Solid energetic composites have been used and studied in standard air environments, yet the contribution of atmospheric oxygen to reactive material combustion has not been investigated. This study experimentally examines the effect of atmospheric oxygen concentration (4% or 93% oxygen) on energy propagation of nanometric aluminum with copper oxide (Al + CuO), iron oxide (Al + Fe2O3), calcium iodate (Al + Ca(IO3)(2)), and iodine pentoxide (1205). In all cases energy propagation was examined in terms of flame speed and higher in the high oxygen environments. However, the convectively dominant reactions showed a smaller percent increase in flame speed mainly attributed to the reaction mechanism. (C) 2013 The Combustion Institute. Published by Elsevier Inc. All rights reserved.