An entropic explosion is an explosion in which the reactants undergo a large change in volume without releasing a large amount of heat. The chemical decomposition of triacetone triperoxide (TATP) is an example of an entropic explosion. It is not a thermochemically highly favored event because little energy generated in chemical bond formation in reaction products, but rather involves an entropy burst, which is the result of formation of one ozone and three acetone gas phase molecules from every molecule of TATP in the solid state.