Puro.earth’s role is to provide the market with clear, science-based rules that enable carbon removal to scale with integrity. As the global biochar sector continues to grow, so do the applications, distribution models and use pathways that must be reflected in robust carbon accounting. 

Biochar Methodology Edition 2025 introduced several major advancements, including stricter biomass sourcing criteria, enhanced treatment of mobile pyrolizers, and an updated durability threshold aligned with the latest persistence science. The update also refined treatment of use pathways by initially excluding retail distribution (Category R3) from CORC eligibility until suitable safeguards could be defined. 

Retail distribution represents a distinct risk profile from direct on-farm application or contracted industrial use, particularly in regions where consumer products may enter mixed waste streams. During the public consultation period (April 2025) for Edition 2025, several proposals were put forward to include retail use directly within CO2 Removal Certificate (CORC) generating projects. However, at that time, none of the proposals provided a sufficiently robust framework to address reversal risk and traceability. 

Edition 2025, therefore, maintained retail use as permitted, but not eligible for CORCs, pending further technical development. 

Why Retail Use Matters 

Retail distribution has become a meaningful channel for biochar in several markets. It expands access through consumer applications, supports diversification of use cases, and strengthens project economics where credit revenue alone may not yet sustain scale. 

With the right safeguards, retail channels can support market growth while remaining fully compatible with high-integrity carbon accounting. 

From Technical Review to Methodology Rule Change 

Following the release of Edition 2025, Puro convened a targeted technical working group comprising biochar market experts and suppliers that use retail channels as part of their distribution approach. This process followed Puro.earth’s governance framework: technical evaluation, stakeholder engagement, and independent Advisory Board approval. 

The objective was to evaluate whether retail applications could be included within CORC-generating certification in cases where carbon removal is demonstrable, risks are understood, and safeguards are enforceable. 

That work has now concluded. 

What the Update Delivers 

The Advisory Board has now approved a minor rule change to Biochar Methodology Edition 2025 that enables biochar use type Retail to individuals (Category R3 in Table 3.2) to be eligible for CORCs under defined conditions and safeguards, including: 

• Product-level risk controls e.g. particular size and moisture requirements for pure biochar 
• Clear consumer guidance and labelling for eligible uses 
• Contractual clarity with the final tracked intermediary in the distribution chain 
• Country-level reversal-risk discount factors 
• Conservative accounting for transport emissions 

Details can be found in the updated Biochar edition 2025 v2 methodology available in the Puro Standard document library. 

Download Methodology

Collaboration Is How Standards Mature 

As carbon removal moves toward industrial scale, standards must continue to evolve through structured engagement and transparent governance. 

The working group process demonstrated how this works in practice: 

• Market expertise informed practical application 
• Scientific review reinforced rigour 
• Independent governance ensured credibility 

This is how durable carbon-removal infrastructure is built: by bringing evidence, experience, and market realities into alignment. 

Looking Ahead 

Biochar is one of the fastest-moving areas of engineered carbon removal. We would like to thank US Biochar Initiative and all participants in the retail-use working group for the constructive engagement they brought to the process. 

Methodologies do not stand still. They are living technical documents that must evolve as science advances, markets develop, and new evidence emerges. Some updates raise requirements where confidence grows. Others refine application where implementation reveals new complexity. Both are essential to maintaining credibility at scale. 

We remain committed to continuous, evidence-led improvement, ensuring CORCs remain scientifically grounded, operationally robust, and trusted by the global carbon-removal market.