An integrated of fuzzy-WASPAS and E-FMEA methods for environmental risk assessment: a case study of petrochemical industry, Iran.

Due to the scope and volume of activities, the petrochemical industry has a high potential for risk to humans and the environment. This study aimed to evaluate the environmental risks caused by the ammonia and urea production process. To screen the risks identified in the follow-up phase, the process hazard analysis (PHA) was used. The environmental aspects were also assessed using environmental failure mode and effects analysis (EFMEA). The most significant environmental aspect with a Risk Priority Number (RPN) of 100 was related to CO emissions from the disposal tower. To rank the final aspects, the criteria "severity," "probability of occurrence," "probability of detection," and the "extent of contamination" were first weighed by the fuzzy Shannon entropy method. Then, each aspect was prioritized based on the mentioned criteria and using fuzzy Weighted Aggregated Sum Product Assessment (WASPAS). According to this technique, among the 24 environmental aspects, the highest score (with a value of 0.702) was given to CO emissions from the disposal tower. Finally, suggestions were made to mitigate the risks.