DNV charting ammonia’s course through regulatory waters

Ammonia’s primary appeal lies in its ability to provide carbon-free combustion, giving it a strong environmental advantage over traditional fossil fuels. “Ammonia is emerging as a possible fuel option, in part, due to its carbon-free combustion,” Stefanatos explains. Compared to hydrogen, it offers practical advantages in storage and transport—two major hurdles for large-scale maritime use.

Existing infrastructure also gives ammonia a head start. “The usage of ammonia as a cargo provides a basic infrastructure ashore, through more than 250 ammonia terminals, and some experience from handling ammonia onboard.” However, while ammonia’s energy density and scalability are attractive, it still lags behind methanol in terms of technological maturity and ease of integration. “Technological challenges, especially regarding safety are to be overcome before we see widespread adoption,” he adds.

Regulatory gap in safety

One of the key barriers to ammonia adoption is the lack of fully developed regulatory frameworks, particularly in safety standards. With ammonia being toxic and corrosive, managing its risks is paramount.

DNV has stepped in to fill this regulatory void. “DNV has proactively developed classification rules and recommended practices to ensure the safe use of ammonia as a marine fuel,” Stefanatos says. This includes DNV-RP-0699, a recommended practice focused on crew competencies. Through these guidelines and partnerships with industry stakeholders, DNV is helping to build the foundational knowledge and protocols needed for future regulations.

“By providing detailed guidelines and facilitating early dialogue with Flag Administrations, DNV aims to mitigate risks and ensure safe operations even before mandatory regulations are fully established.”

Shipowners exploring also face considerable uncertainty due to the novelty of the fuel. The Alternative Design Assessment (ADA) process—used to validate safety where prescriptive rules do not yet exist—can be particularly complex.

“A hurdle shipowners can encounter during the ADA process is the lack of precedent,” Stefanatos explains. “DNV utilizes the experience gained by previous projects… facilitating early engagement with flag states and helping structure submissions to clearly map out safety justifications.” Drawing on cross-sector risk models, DNV offers a bridge between conceptual safety and regulatory compliance.

First mover advantage

Initial adoption is being seen among vessel types that can maximize ammonia’s benefits. “In the AFI orderbook we have seen the first non-gas carrier ammonia-fuelled vessel orders placed in 2024, mainly in the bulk carrier segment,” says Stefanatos. Long-haul vessels such as bulk carriers, gas carriers, and container ships—particularly those calling at ports with existing ammonia infrastructure—are expected to lead the way.

“As large-scale availability is not there yet, it is safe to assume that ammonia will first come to liners that call at specific ports,” he notes, highlighting the importance of targeted infrastructure development in early adoption phases.

The transition to ammonia also places new demands on shipyards and vessel designers. While the market has begun to respond—with a growing number of ammonia-ready vessels on order—full integration of ammonia-specific safety measures is still developing.

“Shipyards and designers are embracing ammonia readiness… However, there is still a gap in terms of fully integrating ammonia-specific safety features and operational protocols,” says Stefanatos. DNV’s classification rules and ongoing technical support aim to bridge this gap, enabling the industry to adapt as new propulsion systems begin rolling out. “With the first engines being delivered by the end of this year/ beginning of next we expect to gather more real-life experience around the potential issues.”

All eyes are now on the IMO, which is expected to deliver new regulatory guidance around 2028 under its IGF Code expansion. Stefanatos sees promise in the organisation’s evolving stance but remains cautiously optimistic.

“The IMO has shown increased commitment through its revised GHG strategy… However, clarity will depend on the level of ambition and whether prescriptive safety requirements are sufficiently flexible to accommodate innovation.”

Ammonia may not be the most mature or straightforward fuel alternative today, but its potential to contribute to the IMO’s net-zero goals is undeniable. With organisations like DNV stepping in to create interim frameworks and support shipowners in uncharted waters, the pathway to ammonia adoption is gradually taking shape. Whether the regulatory winds will be favourable remains to be seen, but the industry is clearly setting sail.