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 that further refinements will be necessary as operational experience is gained, particularly in relation to toxicity controls and emergency systems.
See the full interim guidelines (MSC.1/Circ.1687).
Related regulatory developments
In parallel to these interim provisions, the IMO is progressing work in several areas.
To clarify the application of the International Code of Safety for Ship Using Gases or Other Low-flashpoint Fuels (IGF Code), amendments to SOLAS Chapter II-1 were approved at MSC 109 to ensure gaseous fuels, including ammonia, are explicitly covered. Moreover, the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) was updated to allow ammonia-fuelled operations on ammonia carriers.
Regarding seafarers training, the 11th session of the Sub-Committee on Human Element, Training and Watchkeeping (HTW) finalised Generic interim guidelines for the training of seafarers on ships using alternative fuels and new technologies. These guidelines establish both basic and advanced training requirements, outline standards of competence, and mandate regular emergency drills. Approval is expected at MSC 110 in June 2025. At the same time, HTW 11 initiated the development of fuel-specific training guidelines. A prioritisation was agreed, with training programs for methyl/ethyl alcohol, ammonia, fuel cells, LPG, hydrogen, and batteries to be developed in that order.
BIMCO’s engagement
BIMCO has been continuously engaged in the IMO’s work on ammonia safety and crew training. In parallel, we contribute to various industry-led projects supporting the safe uptake of alternative fuels.
We will continue to actively participate in regulatory developments and collaborative initiatives and will keep our members informed as new guidance and requirements evolve in this rapidly developing area.
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