A Review of Safety Issues and Risk Assessment of Industrial Ammonia Refrigeration System

Several industries like cold storage and ice plants heavily rely on ammonia (NH3) due to its low cost, excellent thermophysical traits, and zero effects on the ozone layer. Despite its widespread use as a refrigerant, the hazardous nature of ammonia remains a significant health concern. Since the industrial revolution, ammonia leakage has led to numerous major accidents, including fire and vapor cloud explosions. This paper reviews the safety issues and the current practices of risk assessment with regard to the industrial ammonia used in refrigeration systems. In addition, previous works related to the risk analysis of ammonia-based industries are reviewed. The majority of ammonia refrigeration system-related works applied the traditional static tools for risk analysis such as fault tree, event tree, and bow-tie that are not suitable to handle common causes of failures or conditional dependencies, which are absolutely significant aspects for a reliable safety assessment. Thus, it is vital to maintain and improve the safety levels of diverse industries using ammonia-based refrigeration systems. Various characteristics of ammonia-based refrigeration systems and their safety issues related to industry, present development, and future trends are comprehensively underscored. This review may act as a guide to develop a better understanding of dealing effectively with the hazards of ammonia-based refrigeration systems and risk assessment, thus enhancing the overall safety of humans and the environment.