Green Iron Certification: which chain of custody models should be prioritised to support steel decarbonisation in Asia?

The workshop will focus on the chain of custody models to be used for green iron certification in Asia. There is currently only limited green iron and green steel production and thus limited practical experience with green iron and green steel certification. While dedicated green supply chains (“identity preservation” chain of custody) models are the norm, mass balance and book and claim certification approaches are attracting growing interest to support early movers, both on the supply and demand side. There are also concerns that the misuse of these certification models could enable greenwashing and crowd out investment in net-zero aligned projects. 

Speakers to include: 

• Joe Williams, CEO GH2 - Introduction & scene setting  

• Sam Bartlett, Director: Standards, GH2 - Emerging definitions of green iron and the chain of custody options for green iron certification.  

• Nicole Wyche, Industry Decarbonisation Manager (Steel), WWF Australia. Presentation to include the findings from “Green steel demand in Japan – market status and enablers” and “Building trust: A guide to navigating the global verification regime for greening iron & steel – Opportunities for international collaboration and coordination”. 

• Chuyi Lu, Program Officer, Solutions for Our Climate: “Defining Green Steel: Advancing the Transition” 

• Transition Asia, speaker and presentation title TBC. 
   

Background 

The steel industry is one of the largest sources of greenhouse gas emissions. Scaling green iron production is crucial for aligning the sector with net-zero climate targets. Green iron production replaces coal-based reduction (blast furnaces using coke) with low-carbon pathways such as hydrogen direct reduced iron (H₂-DRI) powered by renewable electricity, eliminating most process CO₂ emissions at the primary ironmaking stage. Because iron production accounts for the majority of the steel sector’s lifecycle emissions, decarbonizing this step can cut total steel GHG output by roughly 60–90% depending on the energy mix.  

It has often been noted that the absence of a clear definition of green iron undermines project and market development. Some of the most contentious issues include the utilisation of natural gas (in electricity, hydrogen and iron production) and what qualifies as renewable electricity utilization (i.e., the application of the so-called “three pillars”). In late 2025, GH2 published the Green Iron Principles to promote best practice in addressing these issues.  

This workshop will focus on the chain of custody models used to certify iron that meets an agreed standard. The recently developed ISO standard for chain of custody models (ISO 22095:2020) defines a framework for chain of custody by providing a consistent generic approach to the design, implementation and management of chains of custody. It covers 5 models: identity preserved, segregated, controlled blending, mass balance, and book and claim, provides harmonized terminology and general guidance on the application of the defined chain of custody models, including initial guidance on the circumstances under which each chain of custody model might be appropriate. In January 2026, the ISO standard was amended with additions specifically for the chain of custody models mass balance (ISO 22095-2) and book and claim (ISO 22095-3). 

This workshop will focus on three chain of custody models for green iron: 

1. Identity Preservation - A chain of custody model that tracks the green iron / green steel as it moves through the supply chain. It doesn’t allow the certified product from a certified site to mix with other certified or non-certified sources.  
2. Mass balance - Tracks the total amount of sustainable content through the production system while ensuring an appropriate allocation of this content to the finished product. This allows for the mixing of sustainable materials with nonsustainable materials.   
3. Book & Claim - Certified and non-certified materials flow freely through the supply chain, with neither traceability nor any physical connection between the final product and the certified supply. A central authority ensures that the number of credits issued and traded matches the sustainability claims.  

While dedicated green supply chains (“Identity preservation”) are usually the norm, mass balance and book and claim certification approaches are attracting growing interest and support. Book and Claim offers the most flexibility and the lowest barriers to entry. There are no transport costs because there is no physical connection between the final product and the certified supply. The model has potential to support early movers, both on the supply and demand side.  

There are three challenges: 

1. Credibility – many stakeholders have concerns about double counting and greenwashing, and negative experience with previous credit trading schemes; 
2. Competition – safeguards are needed to ensure that these systems do not undermine the physical trade in green iron; 
3. Regulatory acceptance – in some jurisdictions, unbundled certificates are not eligible, i.e., cannot be counted toward decarbonization targets. The viability of these schemes therefore depends on careful targeting, strong oversight, transparency and accountability mechanisms. 

The workshop will explore these key features and consider their implications for green and low carbon iron and steel market development.