IMO moves forward with interim guidelines for ammonia fuel use

Approval for changes to IGF, IGC codes this December

Following a meeting of the Sub-Committee on Carriage of Cargoes and Containers (CCC) at the IMO this September, interim guidelines for the use of marine ammonia fuel have been sent to the Maritime Safety Committee (MSC) for consideration and approval. After anticipated approval at the MSC’s upcoming December meeting, the shipping industry will finally have an international standard for the safe operation of vessels using marine ammonia fuel. Revisions and additions are already anticipated as the first vessels gain sailing experience, and a formal revisit of the guidelines is scheduled for 2027 (possibly late 2026). A number of ammonia-powered vessels are set to hit the water and begin operations in 2026.

The interim guidelines for the use of ammonia fuel are the result of years of work and steady progress. Based on the existing International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF code) and working within the SOLAS Convention, a number of key amendments have been proposed. As the American Bureau of Shipping reports, discussions at the CCC meeting included:

• Differentiating “toxic areas” and “toxic spaces”, with the former being on open-deck and the latter enclosed. Toxic area boundaries should be set based on gas dispersion analysis for accidental ammonia releases
• The introduction of a “safe haven” space able to accommodate everybody on board
• The discharge criteria for ammonia release mitigation systems will be set below 110 ppm
• Guidelines for ammonia effluent and discharges into the sea will be developed and submitted in 2025

In terms of using ammonia cargo as fuel, an amendment to the IGC code must be made that removes the prohibition of the use of toxic cargo as fuel. This amendment was agreed to at the last meeting of the MSC and is scheduled to enter into force from 1 July 2026, and in December a “voluntary early implementation provision” will be considered. As Lloyd’s Register reports, from this December, flag authorities may be able to apply for exemption from the toxic cargo-fuel prohibition on a case-by-case basis.

And all this progress occurs as the IMO considers methods for assessing the lifecycle GHG footprint of new marine fuels. At the meeting of the Marine Environment Protection Committee (just commenced), a series of “mid-term” decarbonisation measures will be considered for entry into force. These measures include a goal-based standard for the phased reduction of shipping GHG emissions, and an emissions pricing mechanism.