An overview of ISCC certification for clean fuels

If you produce a low-carbon molecule, e.g. renewable natural gas (RNG), biomethane, sustainable aviation fuel (SAF), renewable diesel (RD), ethanol, the market no longer takes your carbon intensity on faith. Buyers, regulators, and lenders want an independent certification body to stand behind the number. For a growing share of that market, the certification they're asking for is ISCC.

ISCC, the International Sustainability & Carbon Certification scheme, verifies that a fuel or feedstock is sustainable and that its greenhouse-gas footprint is calculated correctly and traceable end to end. While ISCC certification is not mandatory for all jurisdictions, in practice it has become a gatekeeper: without it, a molecule often can't command the premium its low carbon intensity should earn.

First, know which ISCC you need

"Getting ISCC certified" isn't one thing. The scheme has several variants, and the right one follows directly from where your molecule is sold and who is buying it. Establishing that early keeps offtake conversations aligned and your documentation scoped correctly from the outset.

How Mangrove gets you certified

Certification is a shared effort between three parties: the producer, who owns the site and the data; Mangrove, the certification engine that runs the CI/GHG calculations, generates the documentation, and manages the verification workflow end to end; and the certification body (the independent auditor) who runs the gap analysis and on-site audit and ultimately issues the certificate.

Left to a producer alone, a first-time certification can stretch across many months of documentation, coordination, and back-and-forth with auditors. With Mangrove, the same path is compressed into a few months and most of the work sits with us. The sequence below shows where we take the load off so your team can stay focused on running the plant.

An underrated advantage of this sequence: an indicative CI score is available well before the certificate is issued. Producers can put a credible, defensible carbon-intensity number in front of offtakers months ahead of full certification, often the difference between being in a deal conversation and being left out of it.

What certification requires, and what Mangrove handles

Underneath the timeline, certification comes down to three core deliverables. These are the requirements Mangrove builds and maintains for you, so that by audit day the review is largely a confirmation exercise.

Where projects get stuck

The certification process itself is well-documented and predictable. The friction almost always shows up in the same few places:

• Input certification lags output claims. Every input material, such as feedstock and biogas, must be ISCC-certified first before the output (say, biomethane) can carry the claim. Sites routinely discover their input paperwork is out of date at the worst moment and lose a slice of certifiable volume, a direct hit to revenue.
• The paperwork outweighs the math. The CI calculation is often the easier part; the volume of documentation and evidence is what overwhelms teams without a system to manage it.
• Default vs. actual data. Default values are often easier to obtain than metered actuals, but offtakers increasingly prefer real data, so plan your metering where feasible.
• Small plausibility gaps. Auditors look for the details that let them sanity-check quickly: facility capacities, conversion factors, and raw-material classifications that match the ISCC list exactly.

Burnham RNG upgrades biogas into renewable natural gas. When they needed ISCC certification to open up premium offtake, Mangrove built the CI/GHG calculation, stood up the mass-balance system, assembled the management-system handbook and evidence files, and coordinated directly with the certification body through gap analysis and beyond. The gap-analysis sessions came back clean, with the auditor treating the handbook as essentially done, and the same playbook now extends to their next sites.

The takeaway

ISCC certification is achievable and increasingly non-negotiable for clean-molecule producers who want real market access. The scheme is clear; the timeline is predictable; the deliverables are well-defined. What separates a smooth certification from a stalled one is whether your data and documentation live in a system built for it or in a pile of spreadsheets that goes stale the moment operations change.