The bachelor thesis is focused on the use of the explosion chamber VK 100 for the experimental determination of the lower explosion limit, which is one of the fire parameters.The aim of the work was to characterize the general properties of substances entering the combustion reaction and the basic knowledge of the explosion. Defining the physical and chemical properties of flammable substances in terms of fire hazard. Describing the methodology of work and material used to determine the lower explosion limit of three types of flammable substances as one of the fire performance characteristics. We characterized the explosion chamber VK 100 and the possibilities of its use.To achieve this goal, we used a technological equipment with a technological process to produce steel in the presence of dusty magnesium. Certain criteria and procedures were not adhered to in the technological equipment and explosion occurred in the technological equipment. Based on the fire-technical characteristics, we have determined the zones of explosion in the technological equipment, namely zones 20, 21 and 22.By the bachelor thesis we wanted to point out that for various technological processes certain rules and criteria must be adhered to in order to avoid explosion during the technological process in the technological equipment. We therefore propose to remove the original dust-free material to avoid the need for additional safety measures. Magnesium powder has a low initiating energy, so it is not possible to eliminate all sources of ignition. In this case, as a precautionary measure, we would choose to apply inert gas.