What carbon data should a buyer ask for on zinc from a Peruvian refinery?
Emissions per tonne of zinc from roasting, leaching and electrolysis, with the electricity used and its factor, plus the concentrate's upstream figure if the refinery has it. Zinc is outside CBAM, so the buyer relies on the refinery's own evidence.
What goes in
- Electrolysis: by far the largest power use.
- Roasting and leaching fuel.
- Concentrate mining and transport, upstream.
Co products
Refineries also make sulphuric acid and other metals. Ask how emissions were split.
For galvanisers
Zinc enters coated steel. If you export coated steel to the EU, CBAM counts your direct emissions; zinc stays in your Scope 3.
What Senseible does here
Senseible turns supplier invoices into a Scope 3 record with the supplier, quantity and factor behind every figure, so you can see which supplier data is still missing.
Sources: GHG Protocol Corporate Value Chain (Scope 3) Standard, GHG Protocol Scope 2 Guidance
Last reviewed 2026-10-21.