This paper is a summary of observations and possible chemical mechanisms for the acceleration of the thermal decomposition of nitramines octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazocine (HMX) and hexahydro-l,3,5-trinitro-l,3,5-triazine (RDX), and of propellants derived from them, by salts containing the anions B10H70 and B12H72. Available literature on the thermal behavior of salts containing these anions are reviewed as well as available information on the effects of these salts on the decomposition and combustion of HMX and RDX. The emphasis is on thermal decomposition and salts with alkali metal cations. The pure salts appear stable under vacuum or inert gas to ~700-800°C, but there are reports of H 2 evolution at about 620-650°C. In the presence of air, thermo-oxidative degradation at somewhat lower temperatures (~300-600°C, depending on the nature of the salt) is observed. When the salts are heated together with RDX, considerable enhancement of the decomposition rate of RDX is observed; this begins at the melting temperature of pure RDX and becomes intense, leading to a lower, much sharper decomposition exotherm. These observations seem consistent with an acceleration mechanism involving attack on the nitramine by the B-H hydrogens of the boron hydride salt, but it is difficult to evaluate the role of other processes or the reaction of the accelerant with products, particularly nitrogen oxides.