The threat of biological weapons is a major concern in the present day and has led to studying methods to neutralize spore forming bacteria. A new technique involves the use of a thermite reaction that exhibits biocidal properties to limit bacterial growth. The objective was to examine the influence on bacteria growth upon spore exposure to thermite reactions with and without biocidal properties. Three thermites are considered: two that have biocidal properties (aluminium (Al) combined with iodine pentoxide (I2O 5) and Al combined with silver oxide (Ag2O)); and, one that produces a highly exothermic reaction but has no biocidal properties (Al combined with iron oxide (Fe2O3)). Results show that Al + I2O5 is extremely effective at neutralizing spores after only one hour of exposure. The temperature generated by the reaction was not determined to be an influential factor affecting spore growth kinetics. Further analysis of the thermite reactions revealed that the Al + I2O 5 reaction produces iodine gas that effectively interacts with the spores and neutralizes bacteria growth, while the Al + Ag2O reaction temperature does not vaporize silver. In the condensed phase silver does not interact with the spores enough to neutralize bacteria growth. This study gives evidence that a thermite can be used as a stable transportation and delivery system for biocidal gas.