Confined spaces represent a critical issue for the safety of workers. Several accidents, often fatal, occurred in the process industry, caused by inadequate education and training about the possible formation of toxic and/or explosive atmospheres generated by the variation of environmental parameters such as temperature, or by the working operations, which may involve the handling of hazardous impurities. The present study proposes a quantitative methodology to support the identification of hazards in process equipment considering the subsequent assessment of risks to which workers are exposed and suggests the preparation of appropriate working procedures. The proposed methodology, starting from the specific site data, allows the operators to predict the parameters needed for the quantitative evaluation of the possible hazards and the associated risks arising from the operations carried out in the process equipment. The methodology is tailored to the specific case of the food industry, and particularly edible oil refining storage. Based on the outcomes of the method, besides determining a hazard ranking of the considered operation, it is possible to establish the specific training requirements of operators, the appropriate personal protective equipment to be used, and, finally, the working procedure. Finally, in order to apply the results obtained, case studies based on the analysis of realistic industrial plants are presented and discussed.