The thesis deals with the problem of modeling the leakage of selected hazardous substance into the air from a stationary source. A total of 33 escape scenarios were modeled hazardous substances in order to analyze and assess the impact of changes in selected parameters environment to the extent of the hazardous area by toxic concentration of the dangerous substance. In the first chapter, the thesis deals with legal regulations in the field of hazardous substances, theoretical aspects of hazardous substances or the processing of literature search in the focus issues. In the following sections, the thesis deals with the determination of model scenarios of the selected hazardous substance leakage, their modeling and the assessment of the influence of individual input parameters on the results of the investigation. The importance of the worklies in the identification of environmental parameters that have a significant impact on the extent of the threatened area by toxic concentration of the dangerous substance.