In order to contribute to the risk knowledge that people and the environment can suffer from accidents related to process safety this paper presents a case study of Quantitative Risk Analysis applied to the Gases Industry. Industry activities such as production, storage or handling related to dangerous materials are complex and highly prone to severe or catastrophic accidents. All these happen not only because of major accidents occurrence, society pressure, law compliance and because of the growing care about the environmental sustainability by companies and their stakeholders. We address the importance of managing risk and present usual methods of qualitative and quantitative risk analysis studies. Such combination make possible analyze the feasibility of an industrial venture. Developing a case study for the process of cooling with ammonia in GÁSMIL, performing a risk analysis, through vulnerability analysis and knowledge of these subjects, one can map affected areas by the accidental scenarios.