Does CO2 from limestone and dolomite flux count in a steel plant's CBAM figure?

Yes. CO2 released from carbonates used as flux or in sinter, such as limestone and dolomite, is part of the installation's direct emissions. Use about 0.440 t CO2 per tonne of pure calcium carbonate and 0.477 for dolomite, adjusted for purity, or capture it in a mass balance.

How to count it

1. Tonnes of limestone and dolomite charged in the period, from stock and consumption records.
2. Purity from the supplier certificate or lab.
3. Multiply by the carbonate factor and by purity.
4. Or include carbonates as carbon inputs in a mass balance.

Burnt lime is different

Lime you buy has already released its CO2 at the lime kiln. It is not a CBAM precursor for steel, so it adds nothing to your direct emissions.

Example: 12,000 t of limestone at 92% purity

• 12,000 × 0.92 × 0.440 = 4,858 t CO2
• Add it to the plant's direct emissions for the period

Use the purity and factor from your own records where available.

What Senseible does here

Senseible reads fuel, electricity and purchase invoices into dated, fingerprinted installation records, the starting point for the actual emissions an EU importer asks for. It does not file CBAM declarations or verify emissions.

• Process CO2 from calcination
• Is lime covered by CBAM?
• Blast furnace steel precursors

Sources: CBAM Regulation (EU) 2023/956, consolidated, Implementing Regulation (EU) 2023/1773, production routes and monitoring, 2006 IPCC Guidelines for National Greenhouse Gas Inventories

Last reviewed 2026-10-22.