# Does organic carbon in limestone add to a cement plant's CBAM figure?

Canonical: https://senseible.earth/answers/does-organic-carbon-in-limestone-count-cbam

Yes. Carbon in the raw meal that is not carbonate, such as organic matter or shale carbon, burns off in the kiln and the resulting CO2 counts as a process emission. It is usually small next to calcination, but it belongs in the figure when you report actual emissions.

## Where it comes from

Some limestone, clay and shale carry organic carbon. In the preheater it oxidises to CO2 alongside calcination CO2.

## How to count it

- Test total organic carbon in raw meal as part of your lab routine.
- Multiply carbon content by raw meal tonnes and by 44/12 to get CO2.
- Report it with calcination as a process emission.

## When to skip it

If tests show it is negligible, record the tests and the reason in your monitoring notes rather than leaving it out silently.

## What Senseible does here

Senseible reads fuel, power and production records into dated, fingerprinted installation records, the starting point for the actual emissions your EU importer asks for.

- [Kiln bypass dust correction](https://senseible.earth/answers/cement-kiln-bypass-dust-calcination-correction)
- [Slag in raw meal](https://senseible.earth/answers/marmara-cement-slag-in-raw-meal-co2)
- [Is cement covered by CBAM?](https://senseible.earth/answers/is-cement-covered-by-cbam)

Sources: [Implementing Regulation (EU) 2023/1773, CBAM reporting rules](https://eur-lex.europa.eu/eli/reg_impl/2023/1773/oj/eng), [2006 IPCC Guidelines for National Greenhouse Gas Inventories](https://www.ipcc-nggip.iges.or.jp/public/2006gl/), [CBAM Regulation (EU) 2023/956, consolidated](https://eur-lex.europa.eu/eli/reg/2023/956/2025-10-20)

Last reviewed 2026-10-22.