The Material Circularity Indicator

Circularity is easy to assert and hard to compare. The Material Circularity Indicator was developed to make it a number, and understanding what that number does and does not contain is the difference between using it well and misusing it.

What MCI measures

MCI is a material flow measure. It asks where the material in a product came from, where it goes afterwards, and how hard the product worked while it existed.

A product made entirely from virgin material, used for an average life and then landfilled, scores at the linear end. A product made from recovered material, used longer than average and fully recovered afterwards, approaches the circular end.

The utility factor does the interesting work

Without a utility term, a metric based only on feedstock and end of life would reward a disposable product made from recycled material over a durable one made from virgin material. That is the wrong answer and the utility factor is what prevents it.

Utility compares the product’s lifetime, and its intensity of use, against an industry average for that product type. A product lasting twice as long as the average is doing twice the work per unit of material, and the score reflects that.

What MCI deliberately excludes

Three exclusions matter, and each has produced a misinterpretation common enough to be worth naming.

• Environmental impact — MCI does not measure carbon, water or toxicity. A highly circular product can carry a large footprint, and frequently does.
• Whether recovery actually happens — the end-of-life term reflects what is technically recoverable and intended, not what waste infrastructure in a given market delivers.
• Material scarcity — a kilogram of recovered aluminium and a kilogram of recovered plastic count identically, despite very different supply situations.

The first exclusion is the one that causes real harm when ignored. A product designed for disassembly out of an energy-intensive material may score well on MCI and poorly on any lifecycle impact assessment, and treating MCI as an environmental score licenses exactly that trade.

The second exclusion matters for honest reporting. Assuming a recovery rate that the collection system in a market does not achieve produces a score describing a hypothetical world rather than the one the product is sold into.

Where the passport supplies the inputs

MCI has historically been difficult to calculate at scale because its inputs are exactly the data that manufacturers did not systematically hold.

The last node is the significant one. A passport that records what actually happened to units at end of life turns the end-of-life term from an assumption into a measurement, which is the single largest improvement available to the metric.

MCI alongside ISO 59020

MCI predates formal standardisation of circularity measurement. ISO 59020 now provides a framework for measuring circularity performance, and ISO 59004 establishes the vocabulary and principles that sit beneath it.

These are complementary rather than competing. MCI remains a specific, well-defined calculation; the ISO framework describes how circularity measurement should be scoped, bounded and reported, which is what a metric on its own does not tell you.

For a company choosing what to report, the defensible combination is a named metric calculated to a stated scope, disclosed alongside a lifecycle impact figure so that the material flow story and the environmental story are both visible.

Using it without misleading anybody

MCI is genuinely useful for comparing design options within a category, which is where it was intended to be used. It is weaker as a headline claim, and weakest as a substitute for impact data.

Directive (EU) 2024/825 is relevant here. A circularity score presented as an environmental claim, without stating what it measures and excludes, is the kind of assertion that directive was written to constrain.