Hydrogen ship safety demands secondary enclosures, study finds

A study warned hydrogen’s low ignition energy makes it riskier than LNG, requiring automated barriers.

Hydrogen-fuelled ships require a design-based safety approach, including secondary enclosures for all hydrogen-carrying components, according to a multi-year study by DNV. The study also recommends robust containment and automated protection systems as primary technical safety barriers.

The report highlights that hydrogen hazards differ from other alternative marine fuels, such as LNG. Even small leaks can form quickly ignitable gas clouds, and hydrogen’s low ignition energy and challenges in leak detection increase onboard explosion risks. Additional technical measures are needed to manage leaks and protect crews.

Due to hydrogen’s high flammability and low storage temperatures in liquefied form, seafarers face new occupational hazards. The study recommends crew training to recognise hydrogen-specific risks and follow clear operational procedures. Human behavior and organisational safety culture are cited as additional layers of risk control.

“Hydrogen has a viable path as ship fuel but carries safety risks. Robust safety principles must be integrated early, with collaboration across the value chain and seafarer safety at the center,” said Cristina Saenz de Santa Maria, Interim CEO Maritime at DNV.

“Containment, secondary enclosures, and automated protection systems form the first line of defense. This reflects both the speed at which hydrogen incidents can escalate and the limitations of detection and response once a release occurs, particularly in complex maritime environments,” said Linda Hammer, Principal Consultant at DNV and lead author of the study.

The study also encourages ongoing collaboration between regulators, industry partners, and ship operators to ensure the safe adoption of hydrogen as a marine fuel. It was delivered as part of a multi-year study commissioned by the European Maritime Safety Agency (EMSA), culminating in a final report and a non-mandatory guidance document.