Work safety is a key element in the design and maintenance of industrial workplaces and processes. This article examines occupational safety and the reliability of the human factor in the role of a plastic injection molding machine operator. Analyzing the work process and the dangerous, harmful, and burdensome factors present in the environment and workplace allowed for the identification of occupational hazards. Additionally, factors such as the frequency of threats, the likelihood of events, the possibility of avoiding and limiting damage, and the consequences of events were considered to conduct an occupational risk assessment according to the JSA (Job Safety Analysis) method. Following this, human reliability was assessed by determining the probability of operator errors using the TESEO and HEART methods. Finally, the possibility of using selected immersion techniques on the results of the research was discussed. The research methods and tools used in this study included a literature review and analysis, observation, interviews, and inference.