Regulatory gap analysis for risk assessment of ammonia-fuelled ships

The concept and design of ammonia as a marine fuel are still in the embryonic stage which requires an in-depth investigation of its applicability in terms of its safety and potential risks, both in the design and operational phases of a ship's lifecycle. The paper examines and compares the state-of-the-art safety regulations, rules, standards and guidelines relevant to ammonia-fuelled ships available in various classification societies reports and international regulations such as the IGF codes and summarises their gaps and limitations. The paper critically analyses three major hazards namely toxicity, chemical corrosion, fire and explosion and their potential impact on the human, environment and ship in the event of ammonia leakage. Various hazardous areas considered include ammonia leakage at the bunkering station, fuel preparation room, engine room and storage room and its impact on the ship's general arrangement. In addition, this study reviews and discusses various qualitative and quantitative risk assessment methods employed in ships using low-flashpoint fuels and their relevance and potential suitability for ships powered by ammonia. The paper concludes with important findings and recommendations to aid designers, operators, safety experts, and policymakers in the further development of safety within the framework of risk assessment and management. Overall, this study provides valuable insights into the safety considerations of using ammonia as a marine fuel and highlights the need for further research and development in this area.