Introduction

A finished steel part’s CBAM figure is not just about the factory that made it. Under CBAM, the embedded emissions of a complex good include the emissions of its precursors — the upstream CBAM goods that went into it. Emissions accumulate along the chain, from iron ore through to the part you ship. Understanding that cascade is the key to knowing where your number actually comes from.

What a Precursor Is

A precursor is an input that is itself a CBAM good and is consumed in producing a more complex one: sintered ore and pig iron into crude steel, crude steel into hot-rolled coil, coil into tube or section. At each step, the embedded emissions of the precursor are carried into the next product, alongside that step’s own direct process emissions.

How the Cascade Works

  1. Upstream production creates a precursor with its own embedded emissions.
  2. The next process consumes that precursor and adds its own direct emissions.
  3. The finished good carries the sum — precursor emissions plus each step’s direct emissions, per the CBAM methodology.

Where a precursor comes from several installations, a weighted average applies unless a specific source is evidenced. That means your figure depends on data you do not generate yourself — it sits with your suppliers.

Why It Matters for Your Number

Your product’s CBAM figure is your own direct emissions plus the embedded emissions of your precursors. If you cannot get verified precursor data, you fall back on defaults for those inputs — which inflates the result. Mapping your precursors and securing their emissions data is therefore as important as monitoring your own process. This is exactly the data set out in our CBAM and EPD data checklist.

What to Do

  1. Map your precursors by input, origin and supplier.
  2. Request verified emissions data for each precursor.
  3. Model the total — your direct emissions plus precursors — using the cost guide and calculator.

How EPD Polska / Multicert Can Help

We help producers trace and quantify precursor emissions and build a defensible total. Contact us.

FAQ

Do precursor emissions really count in my CBAM figure?

Yes. For complex goods, the embedded emissions of relevant precursors are included alongside your own direct emissions.

What if I cannot get supplier data?

Default values apply to those precursors, which generally raises the result. Securing verified data is how you avoid that.

References