Carbonated materials represent an attractive pathway for durable carbon dioxide removal, with growing interest from project developers, buyers, and researchers working on mineral carbonation in industrial settings. Our Carbonated Materials methodology has facilitated the development of innovative carbon removal projects, helping to scale mineral carbonation as a viable climate solution.  

As part of the Puro Standard’s regular review cycle, we are initiating a comprehensive update of the Puro Standard Carbonated Materials methodology (Edition 2022 v.3) to integrate the latest scientific insights, align with the most recent Puro Standard requirements, and support high-integrity mineral carbonation projects. 

Projects currently undergoing audit or verification under the existing methodology will continue through the certification process as usual, maintaining the same rigorous standards that uphold market confidence and scientific integrity. 

Why the methodology is being updated 

Since the publication of the current methodology edition, both scientific understanding and practical implementation experience have advanced, and Puro.earth has also evolved its General Rules and guidance for all methodologies. The upcoming revision will ensure that the framework remains scientifically robust, operationally clear, and fully consistent with the Puro Standard requirements.  

Key directions for development 

The major update will revise the full methodology, with more precise and detailed requirements throughout. The update will build on feedback from expert reviewers and our implementation experience with suppliers using the current methodology. While the detailed drafting work is to be defined, several priority areas for development have already been identified: 

• Scope and eligible activity types: Discussing the definition of carbonated materials and clarifying which mineral carbonation approaches fall under this methodology. 
• Quantification and measurement: Expanding the description of eligible monitoring and measurement approaches, and associated requirements or sampling and data quality. 
• Alignment with Puro Standard: Ensuring alignment with the Puro General Rules 4.2 and other updates to Puro Standard documents. 
• Calculation of project emissions: Aligning requirements and guidance on life cycle analysis and leakage with the latest Puro General Rules and good practice from other Puro methodologies, while maintaining a practical level of effort for suppliers. 
• Safeguards, risks, and permanence: Expanding the discussion of environmental and social safeguards, and providing more detailed requirements on end-of-life handling, permanence, and reversal risk assessment​. 
• Uncertainty and transparency: Introducing a more explicit framework for handling uncertainty across quantification, and data publication and transparency. 

Timeline and consultation period 

The update process is scheduled to happen during H1 2026. Given the significance of the changes, a three-week-long public consultation period will be organized, tentatively planned for April 2026. This consultation will include a public and recorded webinar. 

Feedback and working group 

To leverage the expertise of our network, we invite all relevant stakeholders to submit feedback on the current methodology.  

Submit feedback

To ensure the updated Carbonated Materials methodology reflects the latest science and the needs of practitioners, we will also convene a dedicated working group of experts. Stakeholders with relevant expertise on industrial mineral carbonation can apply via the same form (applications are accepted until 10 March). The working group will: 

• Review and comment on draft revisions to the methodology text at key stages throughout the update process. 
• Participate in 3 to 4 workshop sessions during the update process, focusing on specific methodological topics. 
• Help identify where additional guidance or requirements would most improve usability and scientific robustness for real-world projects. 

To ensure efficiency, the working group size may be limited and restricted to entities with significant mineral carbonation expertise. 

Approval and deployment 

After incorporating the feedback received during the public consultation, the updated methodology will be presented to Puro’s independent scientific Advisory Board for approval. Pending approval, deployment of the updated CM methodology is expected to begin in H2 2026, with specific transition dates to be determined.