IBI vs EBC vs Puro.earth vs CSI: The 2026 Biochar Certification Landscape Decoded

The two questions every biochar certification answers

Biochar certifications fall into two families, and confusing them is the most common buyer mistake.

• Quality certifications answer: is this a well-made, consistent, low-contaminant biochar? They set thresholds for fixed carbon, the hydrogen-to-organic-carbon (H/Corg) ratio, polycyclic aromatic hydrocarbons (PAH), and heavy metals. IBI and EBC live here.
• Carbon-removal certifications answer: how much durable carbon dioxide removal does this biochar represent, and is that removal verified and tracked? They set rules for measurement, permanence, and registry accounting so a ton of removal can be sold as a credit. Puro.earth and the CSI C-Sink schemes live here.

A quality certificate does not make a carbon credit, and a carbon-credit certificate does not by itself guarantee soil or filtration performance. Most procurement-grade purchases need to think about both families.

IBI Biochar Standards

The International Biochar Initiative (IBI) published the foundational biochar quality standard. It defines test methods and threshold categories for the parameters that matter in production quality: fixed carbon, the H/Corg molar ratio (the core stability indicator), PAH limits, and heavy-metal ceilings. IBI is a quality-and-safety standard, not a carbon-credit methodology; it tells you the material is well-characterized and within contaminant limits, which is the baseline any serious application should require. Note that the IBI standards program has consolidated under Carbon Standards International (see CSI below), so in 2026 you will often see the IBI lineage referenced through CSI documentation.

EBC (European Biochar Certificate)

The European Biochar Certificate is the European quality standard and, in practice, the most granular of the quality frameworks. EBC defines multiple grades tied to end use, including agricultural, agricultural-organic, and feed grades, each with its own contaminant and quality thresholds aligned to EU rules. For a buyer, EBC’s value is that the grade name carries information: an EBC-AgroBio grade means something specific about contaminant limits and feedstock. EBC also feeds into carbon-sink certification through the linked C-Sink schemes, which is where quality and carbon accounting connect.

Puro.earth

Puro.earth is a carbon-removal crediting platform with a published biochar methodology. It does not certify production quality in the IBI/EBC sense; it certifies the carbon-removal claim, defining how removal is measured, what permanence and durability accounting applies, and how credits are issued and retired on its registry. When a producer says “Puro.earth certified,” they are telling you their carbon credits are verified and tracked on the Puro.earth registry, with a transparent retirement record. For a corporate net-zero buyer, that registry transparency is the whole point: it is the difference between a credit you can audit and a claim you cannot.

CSI (Carbon Standards International)

Carbon Standards International runs both quality and carbon-sink certification. CSI administers the EBC quality program and operates the Artisan C-Sink and Industrial C-Sink schemes for biochar carbon credits, and it has consolidated the legacy IBI standards program. In effect, CSI is where the quality lineage (EBC/IBI) and the carbon-credit lineage (C-Sink) sit under one roof. A buyer seeing “CSI C-Sink” should read it as a carbon-removal credential backed by an EBC-grade quality foundation, with a certificate number to verify.

A note on Verra VM0044 and USDA BioPreferred

Two more credentials show up on biochar spec sheets and are worth placing:

• Verra VM0044 is a methodology under the Verra registry for quantifying carbon-removal from biochar utilization. Like Puro.earth, it is a carbon-credit framework, not a quality standard. Producers selling into the broader voluntary carbon market often reference it.
• USDA BioPreferred certifies biobased content (the percentage of the product derived from renewable biological material). It is neither a quality nor a carbon-removal standard; it supports a biobased-content claim for procurement, particularly US federal procurement. Do not let a BioPreferred logo stand in for a carbon credit.

Which certification does your claim need?

Match the credential to the claim you intend to make downstream:

• “This biochar is well-made and safe for my soil/water application.” Require IBI or EBC quality certification with the contaminant test results.
• “This biochar represents verified carbon removal I can report or sell.” Require Puro.earth, Verra VM0044, or CSI C-Sink with a certificate number and a registry retirement record.
• “This product has X percent biobased content.” Require USDA BioPreferred.
• “It is all certified.” Not a claim. Ask which framework, which grade, and what certificate number, every time.

How ECS verifies certifications

ECS treats certification as something to verify, not to take on faith. When we run an RFQ, we require the producer to name the framework, the grade, and the certificate number, and we check carbon claims against the public registry record (Puro.earth, Verra, or CSI) to confirm the credits exist and have not already been retired elsewhere. For quality certifications we confirm the per-batch lab reports back the threshold claims. A producer that lists “certifications” without naming them has nothing a buyer can audit, and we flag that gap before you sign.

To source biochar against a verified certification, request a quote with your application and the claim you need to make.