Oct : ISO Engagement: Maritime Ethanol Standards

Advancing Maritime Ethanol Standards through ISO Engagement

The Global Centre for Green Fuels (GCGF) is actively contributing to international technical standards discussions on the role of low-carbon alcohol fuels in shipping, with a particular focus on advancing ethanol as a certified maritime fuel.

October 2025, Copenhagen — Clarence Woo, Managing Director of GCGF, participated in the ISO/TC28/SC4/WG18 technical working group meeting on alternative maritime fuels. The session focused on ongoing work related to the development of international standards for marine ethanol and ethanol–methanol blends.

GCGF’s Contribution

During the working group meeting, Clarence delivered a technical presentation addressing:

• Global ethanol fuel specifications

• Key considerations relevant to the development of ethanol standards for maritime applications.

The presentation drew on ethanol specifications currently produced and supplied across major regions, including the United States, Brazil, Europe, and Asia, highlighting areas of alignment as well as differences with potential relevance to engine performance, emissions characteristics, and operational compatibility.

Industry Engagement and Technical Discussion

The meeting brought together a broad range of stakeholders from across the maritime value chain, including engine manufacturers, fuel producers, and technical experts.

Across the technical discussions, several themes were explored, including:

• Reported progress from engine testing involving ethanol and ethanol–methanol blends

• Comparative considerations between alcohol fuels and existing methanol systems using pilot fuels

• The importance of further technical evaluation to understand how regional ethanol specifications may influence engine performance and emissions outcomes

These discussions reflected growing technical interest in alcohol fuels and the importance of continued validation work to support their safe and reliable use in maritime applications.

The Importance of ISO Standards for Maritime Ethanol

Industry participants highlighted the value of globally available ethanol supply and the role of internationally recognised standards in enabling wider market uptake.

The development of an ISO standard for maritime ethanol is widely viewed as a key enabler to:

• Support adoption across dual-fuel and multi-fuel engine platforms

• Provide clarity and confidence for shipowners, engine manufacturers, ports, and bunker suppliers

• Enable major bunkering hubs — including Singapore — to participate in a growing alcohol-fuelled shipping market as part of a multi-fuel transition pathway for shipping

A recognised ISO standard would also support the development of E100 ethanol and ethanol–methanol blend bunkering guidelines, helping ports and bunker suppliers prepare for future operational demand.

GCGF’s Ongoing Role

GCGF will continue to support the ISO standards development process by:

• Providing technical input on ethanol fuel specifications

• Facilitating dialogue between engine manufacturers, shipowners, and fuel producers

• Working toward greater alignment among global ethanol and methanol producers on recommended specifications

In parallel, GCGF is establishing the Marine Ethanol & Methanol Alliance (MEMA) to support a coordinated, global approach to positioning alcohol fuels as credible and scalable maritime fuels aligned with the IMO’s decarbonisation objectives.

* The above summary reflects high-level themes discussed and Clarence’s own contributions and does not attribute views to individual participants.