Although ammonia has been transported by ship onboard liquefied gas carriers for decades, its application as a maritime fuel remains widely uncharted, with technologies such as ammonia-fueled internal combustion engines yet to be proven at scale.
Ammonia is considered a promising, carbon-free maritime fuel for decarbonizing shipping, offering high energy density compared to hydrogen and relative ease of storage. While it has significant potential, major challenges include high toxicity, corrosiveness, and the need for specialized engine technology to handle its slow combustion, making it a high-risk, high-reward alternative.
Some shipping companies have already placed orders for ammonia-fueled vessels, underlining ammonia’s potential as an alternative to fossil fuels. However, its adoption introduces substantial safety and operational challenges, including toxicity, corrosiveness, and the need for specialized fuel systems and engine designs.
Addressing these risks through robust safety protocols, regulatory frameworks, and crew training is essential to ensure the safe and effective integration of ammonia into marine propulsion systems.
Commissioned and published by the European Maritime Safety Agency (EMSA), a new report focused on the safety of ammonia as a marine fuel was developed by an ABS-led consortium that included the National Technical University of Athens (NTUA) and the Fundación Valenciaport.
“ABS remains committed to supporting the maritime industry as it navigates future energy options such as ammonia as marine fuel. This latest report for EMSA reflects our close collaboration with industry stakeholders and academia to provide critical information to advance the discussions around low- and zero-carbon operations for the future,” said Vassilios Kroustallis, ABS Executive Vice President and Chief Commercial Officer.
Based on the insights gained from the study, the report includes recommendations that expand upon existing interim guidelines from the International Maritime Organization for the safety of ships using ammonia as fuel. Commercial engines for ammonia-powered ships are expected to enter operations more widely in 2026 and 2027. By way of a survey and online workshop, industry stakeholders communicated feedback that emphasized the necessity of a comprehensive understanding of ammonia’s properties to effectively mitigate the safety risks associated with its use as a marine fuel.
Professor Nikolaos P. Ventikos of NTUA said: “Exploring pathways toward more environmentally sustainable maritime transport is essential for society, but it must always be pursued with safety as the highest priority. This is why the role of organizations such as EMSA is so important. By funding rigorous research and making its results publicly available, they enable informed decision-making across the entire maritime community. For NTUA, as a university deeply committed to open science, it is particularly meaningful to facilitate and carry out risk assessment studies, such as HAZOP, that are traditionally confidential.”
Josep Sanz-Argent, Director of Energy Transition and Sustainability at Fundación Valenciaport, said: “Ammonia will play a key role in the decarbonization of the maritime sector and ports must prepare for bunkering operations to be carried out safely within their jurisdiction. The results of the study will contribute significantly to preparing that future.”
Read the collection of EMSA reports on Safety of Ammonia for Use in Ships here or click on the links below.
In other industries and applications, ammonia is primarily used as a vital agricultural fertilizer to provide nitrogen to crops. It is also widely used as an industrial refrigerant, a key ingredient in household/commercial cleaning products (glass cleaners, degreasers), and for manufacturing plastics, explosives, synthetic fibers, and various chemicals.
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About ABS
ABS, a global leader in classification services, is focused on delivering a safer, cleaner future for the marine and offshore industries. For over 160 years, ABS has been setting standards for safety and excellence and continues to innovate in the fields of clean technology, digitalization and artificial intelligence, providing industry-leading technical advisory services. With a global network of surveyors, engineers, technology specialists and support staff, ABS works with industry leaders including its members and clients around the world to improve safety in operational performance and efficiency with innovative solutions for the complete life cycle of marine and offshore assets.
About National Technical University of Athens (NTUA)
Founded in 1837, NTUA is the oldest technical university in Greece. Initially established by a royal decree “on architectural education,” it was a technical school operating on Sundays and holidays which offered instruction to those desiring to master in architecture. Today, the university is comprised of nine schools, 512 faculty members, more than four thousand external collaborators, 23,914 students, and 300,000 square meters of installations. The School of Civil Engineering is in the 33rd position of the world’s best schools by specialty. NTUA is in 67th place worldwide among technological universities. Of the 120,000 qualified engineers active today in Greece, the majority (over 40%) are NTUA graduates.
About Fundación Valenciaport
The Fundación Valenciaport is a center based in Valencia, Spain, for Applied Research, Innovation and Training, serving the port logistics cluster. This initiative, launched by the Port Authority of Valencia, has garnered support from leading companies, universities, and institutions within the port community. Since its inception, it has developed projects in more than 65 countries, mainly in Europe in the Mediterranean and Latin America.
