In the past dust explosions triggered severe industrial accidents, in some cases even resulting in deaths. To ensure safety of people and constructions there are lots of measures to avoid such accidents. This happens, for example, by avoiding the formation of explosive atmospheres by adding an inert gas or substance. Zeolite is such an inert substance which is capable of accumulating large amounts of energy. By testing safety-relevant parameters of a combustible dust mixed with zeolite it should be investigated if the zeolite is able to absorb the heat from the uprising explosion fast enough to supress flame propagation energy. For the determination of the suitability of different pretreated zeolites as flame inhibitor MIKE3 apparatus and a vertical flame tube were used.