ClassNK issues guidelines for safe operation of ammonia-fueled vessels

May 13, 2025, by Aida Čučuk

Japanese classification society ClassNK has released new guidelines to support the safe adoption and onboard handling of ammonia as a marine fuel.

Archive; Illustration; Courtesy of ClassNK

These safety and operational guidelines for ammonia-fueled vessels reportedly give priority to the safety of seafarers and cover standard procedures, such as health measures to be taken in the event of an ammonia leak, as well as requirements for personnel protection equipment (PPE) and emergency equipment.

As disclosed, they summarize specific precautions and management methods for the transportation, storage, and operation of ammonia fuel, and provide practical content that can be used in the field from the perspective of seafarers.

Alternative fuel vessels are said to currently account for nearly 40% of all new vessel orders and are expected to increase further in the future. However, as per ClassNK, there is not enough information on the operation of such vessels.

To provide proactive information, the classification society stated that it based its guidelines on the latest data and developments in Japan and the rest of the world, adding that they will be “continuously and flexibly” updated according to future industry discussions, research results, and the latest knowledge.

“As part of the ClassNK Transition Support Services, which comprehensively supports the smooth transition of customers to zero emissions, ClassNK will continue to contribute to the safe operation and active introduction of alternative fuel vessels,” the classification society concluded.

It is worth mentioning that in the past year, ClassNK also released new editions of its guidelines for liquefied hydrogen carriers and guidelines for ships using alternative fuels.