The IMO has issued the Interim guidelines for the safety of ships using ammonia as fuel (MSC.1/Circ.1687), marking a significant milestone in regulatory support for alternative fuels. Finalised by the CCC Sub-Committee and approved at MSC 109, the guidelines offer high-level, goal-based provisions while acknowledging the need for future refinements. BIMCO has actively contributed throughout the process and continues to support the safe uptake of alternative fuels for sustainable shipping operations. The International Maritime Organization (IMO) has issued MSC.1/Circ.1687, the Interim Guidelines for the Safety of Ships Using Ammonia as Fuel. This development reflects a growing recognition of ammonia’s potential as a marine fuel in support of decarbonisation goals, and the need for a structured, risk-based approach to its safe use. The Maritime Safety Committee (MSC) approved the guidelines at its 109th session in December 2024, following their development and finalisation by the Sub-Committee on Carriage of Cargoes and Containers (CCC) at its 10th session in September 2024. BIMCO has actively participated in all aspects of the work contributing to these guidelines and to the development of future mandatory provisions. Goal-based, high-level safety provisions The interim guidelines provide a goal- and function-based safety framework covering ship design, equipment, operations, bunkering, toxicity mitigation, and crew protection. While the guidelines are non-mandatory, they align closely with the IGF Code and SOLAS principles, offering administrations and industry stakeholders a consistent reference point as ammonia-fuelled projects emerge. The guidelines aim to ensure that ammonia-fuelled systems offer at least the same level of safety and reliability as conventional oil-fuelled machinery, recognising ammonia’s specific hazards, including high toxicity, potential for explosive atmospheres, and material compatibility challenges. They encourage early uptake while noting