Auob Mirsaeidi - Department of Natural Resources, Isfahan University of Technology, Isfahan, Iran
Hossein Moradi - Department of Natural Resources, Isfahan University of Technology, Isfahan, Iran
Maryam Zekri - Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, Iran

The main objective of this study was to develop a fuzzy–based framework for the prioritization of health, safety andenvironment related risks posed against employees, working conditions, and process equipment in large gasrefineries. The First Refinery at Pars Special Economic Energy Zone in South of Iran was taken as a case study. Forthis purpose, health, safety and environment related risks were determined based on the three criteria of impactseverity, occurrence probability, and detect-ability using a questionnaire of 33 identified failures. The valuesobtained were processed by a so-called ‘contribution coefficient’. The results were then subjected to fuzzificationand fuzzy rules were defined to calculate the risk level indices as the model outputs, which was then employed tofacilitate the management decision-making process by prioritizing the management options. The prioritizationvalues were then classified in six categories in the order of risk severity. Results revealed that failure in acombustion furnace had the highest rank while failure in the slug catcher ranked the lowest among the risk sources.It was also found that about 0.4% of the identified risks prioritized as intolerable , 79% as major , 20% as tolerable , and 0.7% as minor . Thus, most of the risks (more than 79%) associated with the refinery has thepotential of significant risks. The results indicated that the risk of the pollutant emissions from the combustionfurnaces is the highest. Exposures to harmful physical, chemical, psychological, and ergonomic substances are theother risks, respectively

Failures, Fuzzy Logic, Process Operations, Gas Refinery