EMSA publishes additional reports on the safety of ammonia

Ammonia is one of the alternative fuels currently considered to help with meeting GHG emissions requirements for maritime transport. Consequently, it is expected to provide a contribution to meeting GHG emission reduction targets both at EU and at IMO level. As an advisory body to both the European Commission and EU Member States, the European Maritime Safety Agency (EMSA) has now released parts 3, 4, and 5 of its study series on the safety of ammonia as a marine fuel. Launched in 2023, the series assesses risks and mitigation measures for ammonia-fuelled vessels. The whole series can be accessed here^[1]. Parts 1 and 2 were published in 2024. Below is an overview of the recent publications. While the publications are independent from the discussions and developments made at the IMO, there is still a link as ammonia is considered as one possible solution to meet decarbonisation targets agreed at the IMO.

Part 3: Risk Assessment of a Generic Ship Design

This report presents a hazard and operability (HAZOP) study of a generic Ammonia Fuel Supply System (AFSS), a risk assessment from ports’ perspectives including simultaneous operations (SIMOPS), and consequence modelling of potential leaks. It stresses the need to fully understand ammonia’s unique characteristics to develop effective safety measures.

Part 4: Risk Assessment of a Bulk Carrier Ship Design (Newcastlemax Dry Bulk Carrier)

Using a hazard identification (HAZID) approach, the study finds that ammonia bunkering during simultaneous operations (SIMOPS), especially alongside cargo operations, should be restricted or phased in gradually, especially during the early adoption phase of ammonia-fuelled vessels. Chemical compatibility between ammonia and cargo environments needs further evaluation due to potential interference with safety systems. Ship layouts and emergency preparedness must be adapted to ammonia-specific risks. The report highlights the main hazardous SIMOPS and proposes recommendations and mitigation measures including personnel training, enhanced emergency coordination, and infrastructure improvements such as larger fuel tanks to reduce bunkering frequency.

Part 5: Risk Assessment of a RORO Ship Design (Mega RoRo)

This hazard identification (HAZID) study covers design considerations, consequence modelling, and a probit analysis for toxic exposure scenarios. It highlights ammonia’s toxicity, corrosivity, and flammability, calling for double barriers, short piping runs, robust detection, and redundant ventilation systems. Emergency plans should include safe havens, mustering zones, and clear escape routes. The probit analysis showed low fatality risk (<1% beyond 1 km) for a short leak, but high risk (>70% within 250 m) for a major tank rupture, underlining the role of exposure duration in hazard zone planning.

EMSA has opened a consultation as part of its ongoing series, inviting stakeholders to participate in a survey related to the study’s recommendations. The consultation places the study recommendations within the framework of the existing IMO Interim Guidelines for the safety of ships using ammonia as fuel (MSC.1/Circ.1687). The consultation can be found here^[2] and is open for feedback until 19 September.

[1] https://emsa.europa.eu/publications/reports/item/5264-study-investigating-the-safety-of-ammonia-as-fuel-on-ships.html

[2] https://ec.europa.eu/eusurvey/runner/EMSAAmmoniaSafetyStudy