The UK’s Maritime and Coastguard Agency (MCA) Releases Guidance on Ammonia as Marine Fuel

The UK’s Maritime and Coastguard Agency (MCA) has released new guidance on the use of ammonia as a marine fuel, marking a ‘vital’ step toward enabling wider alternative fuel adoption in the country’s shipping industry.

As disclosed, the guidelines, issued on April 16, 2025, provide a framework for operators, shipbuilders, as well as classification societies looking to develop or retrofit vessels powered by ammonia, a zero-carbon but highly toxic and flammable fuel.

Regulation and Safety Measures

The Maritime and Coastguard Agency’s guidance offers insight into how shipowners can seek approval for the operations of ships that run on ammonia, primarily through the International Maritime Organization’s (IMO) alternative design arrangement (ADA).

The guidelines cover ships above and below 500 gross tonnes, with specific regulations under the IGC Code and a case-by-case approval system, respectively. The MCA has collaborated with operators and classification societies to regulate ships using ammonia under the IMO’s interim guidelines within the IGF Code.

Responsibility and Training

The agency places responsibility on shipowners to ensure ammonia-fueled systems are as safe as conventional ones, requiring regular risk assessments, mitigation strategies, and technical documentation submission. Crew training for handling alternative low-flashpoint fuels like ammonia follows the IGF Code training requirements under the STCW Convention.

The MCA is working with training providers to introduce dedicated courses for ammonia handling, with plans for basic ammonia fuel training in the UK’s maritime curriculum starting September 2025.

Industry Challenges and Recommendations

In a February 2025 report, industry experts highlighted the significance of using ammonia as a marine fuel but noted the workforce challenge in upskilling workers for handling ammonia-related hazards. The report recommended revisions to global training standards, internal analyses by shipowners, upskilling opportunities for seafarers, and competency-based training modules with safety drills by training providers.