Risk Assessment of Potential Chlorine Leakage from Storage Tanks Using Fuzzy Fault Tree Analysis

Abstract

Background: Due to the critical importance of safety in the chemical industry, there is a pressing need to assess and manage the risks associated with the storage tanks of hazardous materials, particularly concerning chlorine leakage. Such leaks can have severe consequences for both human health and the environment. The aim of this study was to calculate the probability of occurrence of the root causes of chlorine leakage from these tanks using the fuzzy fault tree analysis (FTA) technique and to identify and assess the associated hazards. Methods: First, a fault tree was constructed to identify the basic events that could lead to chlorine leakage. Next, the probabilities of these basic events were calculated based on expert opinions. In the subsequent step, minimal cut sets were determined. Finally, using fuzzy logic along with the identified minimal cuts and calculations, the probability of chlorine leakage was assessed. Findings: In this study, four main leakage locations were identified: leakage from inlets or outlets, leakage due to defects in safety systems, and leakage from the tank body. Additionally, 28 basic events affecting chlorine leakage were identified. The probability of chlorine leakage, based on the most critical minimal cut set, was determined to be 0.003952308. This probability was primarily attributed to a defect in the rupture disk of the temperature and pressure control system. Conclusion: The results of this study highlight the significance of employing the FTA technique to identify and evaluate the risks associated with chlorine leakage. By accurately calculating the probability of such leaks, effective measures can be developed to mitigate risks and enhance safety in the chemical industry. © 2026, Isfahan University of Medical Sciences(IUMS). All rights reserved.