A new study by DNV, commissioned by the European Maritime Safety Agency (EMSA), identifies hydrogen as a significantly more hazardous marine fuel than LNG. As a result, hydrogen requires an entirely new approach to safety already at the design stage. Similar conclusions are drawn in a report from the Korean classification society Korean Register.

Hydrogen is often highlighted as a potential future fuel for shipping, but widespread adoption is expected to take time. This aligns with the findings of DNV’s study Safety of Hydrogen for Use in Ships, which points to substantial safety challenges. Unlike LNG, even small leaks of hydrogen can quickly form explosive gas clouds. At the same time, the gas is difficult to detect and requires very little energy to ignite, meaning fires can spread rapidly. This makes hydrogen explosions potentially far more powerful than those in LNG-powered vessels. Hydrogen can also ignite spontaneously when released from high-pressure systems. According to Cristina Saenz de Santa Maria, interim CEO Maritime CEO at DNV, this means traditional safety solutions are not sufficient for hydrogen.

"As new fuel technologies develop, robust safety principles must be built in from the outset. That requires new thinking, early‑stage integration, and close collaboration across the value chain, while keeping seafarer safety firmly at the center”, she says.

The report, the result of several years of work, recommends that all systems handling hydrogen should include secondary protective barriers, even on open decks. The aim is to minimize risks associated with a fuel that behaves very differently from today’s alternatives.

It will also change onboard working conditions. Hydrogen’s high flammability and the extremely low temperatures in its liquid form introduce new risks for crew members. This places demands on both training and clear operational procedures. Seafarers must be able to identify hydrogen-related risks and know how to manage them. Safety should also be supported by well-defined operational procedures and safety management systems, where both human behavior and a strong organizational safety culture act as additional layers of risk control.

According to Linda Hammer, lead author of the study, technical solutions are crucial:

“The study concludes that safety for hydrogen‑fuelled ships must be based on technical safety barriers, with robust containment, secondary enclosures, and automated protection systems forming the first line of defense."

A new report from Korean Register (KR) identifies the same risk factors as DNV and proposes measures for the safe use of hydrogen in shipping. It provides an overview of marine hydrogen systems, analyzes hydrogen-related accidents, and addresses key risks, mitigation strategies, and relevant international regulations.

“We hope this research will serve as a useful reference for industry, academia, and research institutions involved in the development of hydrogen-fueled ships”, says KIM Daeheon, Executive Vice President of KR.

Both reports come at a time when international efforts to establish regulations for hydrogen as a marine fuel are intensifying. Within the International Maritime Organization (IMO) Sub-Committee on Carriage of Cargoes and Containers (CCC), draft interim guidelines have been developed for the safety of ships using hydrogen as fuel. These guidelines are expected to receive final approval in the Maritime Safety Committee (MSC) in May 2026.

To DNV:s report