The course is aimed at enhancing knowledge in the prevention of major accidents in selected technological processes. In connection with the identification of risk sources and quantitative risk assessment, emphasis is put on the approach to risk reduction - the assessment of safety measures for individual technological processes. Safety barriers can be broken down into technical and organizational measures, from another point of view, active, passive or requiring human intervention. Part of the subject is also the reliability assessment of the human factor, where human errors are the main cause of the major accident.