Two numbers, and the gap between them is the whole story

The first number is the carbon footprint of primary aluminium. The International Aluminium Institute publishes a global average figure for the cradle-to-gate greenhouse gas emissions of primary aluminium that is widely quoted at about 16.5 tonnes of CO2 equivalent per tonne of cast metal, covering mining, refining, anode production, electrolysis and casting, including electricity and process emissions. That number is an average, and the spread around it is enormous: a smelter running on hydroelectricity is in a completely different place from one running on coal.

The second number is the saving from recycling. The IAI states that recycling aluminium saves about 95 per cent of the energy required for primary production, and a similar proportion of the greenhouse gas emissions. The reason is that remelting scrap takes a fraction of the electricity that electrolysis does, because the aluminium is already reduced metal.

So the gap between roughly 16.5 tonnes and a fraction of a tonne per tonne of metal is real and it is large. The whole of the rest of this article is about the conditions attached to claiming it, because the gap is only available if the metal in the profile actually comes from the low-carbon route, and that is a question about the supply chain rather than about the alloy.

Pre-consumer and post-consumer scrap are not the same claim

Aluminium scrap comes in two very different kinds, and a recycled-content percentage that does not distinguish them is not very informative.

Pre-consumer scrap, sometimes called process scrap, is the material generated inside the manufacturing chain: the butt ends of extrusion billets, the trimmings from a cut, the swarf from machining, the offcuts from a fabricator. It is clean, it is known, and it is usually remelted back into the same alloy family. It has always been recycled, because it is valuable, and counting it as recycled content is therefore a claim about normal good practice rather than about a circular economy.

Post-consumer scrap is material that has been through a product life: a window that was removed from a building, a car part, a beverage can. Recycling it displaces primary metal in a way that process scrap does not, because the alternative destination for post-consumer scrap is landfill or downcycling. A recycled-content figure that separates the two, and that reports post-consumer content separately, is far more useful than a single number, and it is the number a serious buyer should ask for.

There is a third complication that a percentage hides: alloying. Extrusion alloys are made to a specification, and a remelted scrap stream has to be refined back to that specification, which may require adding primary metal. A high recycled-content claim on a 6063 profile therefore has to explain how the chemistry was held.

Recycled content is a claim that needs a chain of custody

Because recycled content is a claim about the origin of material, it needs a custody model. Three models are in common use, and they give very different assurances.

At the strongest end, physical segregation keeps recycled metal in a separate stream so the claimed content is physically in the product. In the middle, mass balance allows recycled and primary metal to be mixed while the accounting tracks the recycled share across a production period. At the weakest end, a certificate or book-and-claim model allows a recycled-content certificate to be purchased separately from the metal, so the product may contain no recycled metal at all even though the claim is supported on paper.

None of these is dishonest if it is declared. The failure is an undeclared model, where the buyer assumes segregation and receives book-and-claim. So the enquiry should ask which model applies, over what period the balance is struck, and who audits it. A supplier who can answer those three questions is a supplier whose claim can be used in a customer’s own reporting.

CBAM: what changed on 1 January 2026

The EU carbon border adjustment mechanism moved from its transitional period into its definitive period on 1 January 2026. Aluminium is one of the covered sectors, alongside cement, iron and steel, fertilisers, hydrogen and electricity, and the mechanism applies to specified goods identified by their EU commodity codes.

The obligations sit with an authorised declarant, which is normally the EU importer or an indirect customs representative acting in that role. The mechanism works through annual declarations rather than quarterly reports, with certificates purchased and surrendered against the declared embedded emissions. On the published timeline, certificate sales begin on 1 February 2027 and the first annual declaration and surrender, covering 2026 imports, is due on 30 September 2027. Imports in 2026 already carry the liability even though the purchasing happens later.

There is a de minimis threshold: an importer whose annual net mass of the relevant iron and steel, aluminium, fertiliser and cement imports is below 50 tonnes is outside the obligation. The threshold is annual and per importer, and it aggregates across those sectors, so it is not a per-shipment allowance, and going over it brings the whole year’s relevant imports into scope rather than just the excess.

Why a recycled-content claim does not automatically lower a CBAM figure

This is the point that catches people out. CBAM is built on embedded emissions, which are calculated for a defined product and process boundary, and for aluminium the current scope covers direct emissions. A recycled-content percentage is a different quantity: it describes the origin of the input metal, not the emissions of the producing installation.

So a profile made from recycled metal at a plant with a high-emission process and a coal-fired furnace may still carry a significant embedded emissions figure, and a profile made from primary metal smelted with hydroelectricity may carry a low one. The two claims are related but they are not the same, and a buyer who substitutes one for the other will be surprised.

There is also a choice of route. A declarant can use verified actual emissions or published default values for the origin and product. A default value is not automatically worse, and it is not automatically better; it depends on the plant and the commodity. The honest position is that a low-carbon claim is only useful to a CBAM declarant if it is supported by an installation-level, verified emissions figure that fits the calculation rules. A recycled-content certificate is not that figure.

The digital product passport and the environmental product declaration

Two further pieces of European policy point in the same direction, and both are about carrying data with the product rather than making a claim about it.

The first is the digital product passport being introduced under the Ecodesign for Sustainable Products Regulation. The idea is that a product carries a machine-readable record of its composition, its origin and its environmental performance, so that information follows it through the supply chain. For an aluminium profile, the data that would populate such a record is largely the same data CBAM asks for, plus the recycled content and its custody model.

The second is the environmental product declaration, an independently verified summary of a product’s environmental impact produced to a defined methodology. An EPD is the established way to make a footprint claim that a specifier can compare across suppliers, and it is what turns a percentage into a document.

Neither is mandatory for every aluminium profile today. Both point the same way, and a supplier that already holds the underlying data can respond to either without a new project.

What to send, and what to ask

When recycled content or carbon performance is part of the specification, the enquiry should ask for the boundary of the claim, the scrap classification with post-consumer reported separately, the custody model and the period over which it is balanced, the emissions figure with its methodology, and whether the supplier can provide installation-level data for CBAM. Ask also whether a change in the metal source will be notified, because a claim that was true at the first order and unverified at the third is not a claim a buyer can rely on.

The profile itself does not change much. What changes is the paperwork that travels with it, and the buyer’s ability to use it.