How to measure emissions from Metal

What counts as Metal

Metal covers purchased metal products and raw metal materials — from primary metals such as steel and aluminium to specialist metals like cobalt, niobium and tungsten, and finished metal goods such as cans, cutlery, tools and castings. It's reported under Scope 3 Category 1, by weight (kilograms or tonnes) wherever supplier data allows, since ferrous, non-ferrous and specialist metals carry very different emissions intensities per tonne. Scrap and recycled metal purchases are tracked as their own subtype, distinct from primary (virgin) metal.

Metal spans a wide range, from bulk structural steel to small quantities of specialist metals like boron, niobium and tungsten used in manufacturing, plus finished goods such as cans, cutlery and hand tools that are purchased ready-made rather than fabricated in-house. The single biggest lever for accuracy is distinguishing primary (virgin) metal from recycled scrap, since recycled metal typically carries a substantially lower footprint per tonne — if your supplier can confirm recycled content, record it rather than defaulting to a primary metal average. This category sits alongside Mineral, Plastic, Paper and Textiles in the purchased-goods cluster; where a product is made of several materials, split the weight by material rather than filing the whole item under whichever material happens to be heaviest. Casting and non-ferrous processing are tracked as distinct subtypes from raw metal, since forming and alloying add their own emissions on top of the base material.

What activity data you need

Collect the most specific physical unit available. Unit definitions are in Appendix I — Description of Units.

• Tonne
• £ Spend
• $ Spend

Which emission scope it falls under

Metal activity data typically maps to Scope 3 Category 1 under the GHG Protocol. Confirm organisational boundary and ownership before reporting.

Sub-types available in the platform

All 4 sub-types available in the platform.

• Steel
• Aluminium
• Copper
• Other metals

Data entry options

• production type

  Select production type when entering metal activity data in the platform.

Full list of data entry options

Common questions

How much does it matter whether metal is primary or recycled?

It matters a lot — recycled metal generally has a significantly lower footprint per tonne than primary, virgin metal, since it avoids much of the energy-intensive extraction and refining stage. Always ask suppliers to confirm recycled content where cost-effective to do so.

We buy finished products like cutlery or hand tools — do I need to know the exact alloy?

Not necessarily. For finished goods, a general metal category (steel, aluminium, mixed) is often sufficient; exact alloy detail matters more for bulk raw metal purchases where grade significantly changes the factor.

Do specialist metals like cobalt or tungsten need separate tracking from bulk steel?

Yes — specialist and minor metals typically have very different, often much higher, footprints per kilogram than bulk structural metals, so keep them as separate line items rather than folding small quantities into a general metal total.

What about metal that's cast or machined by a supplier before we receive it?

Casting and forming processes add emissions beyond the raw metal input, so where your supplier can provide a cast or fabricated metal factor rather than a raw metal one, that's the more accurate choice.

How do I handle metal packaging like cans separately from metal used in manufacturing?

Function determines the category, not just the material — metal cans and foil used to package a product belong in Packaging, while metal used as a manufacturing input or sold as a finished metal good belongs in Metal.