Recycled content: what the percentages really hide
Recycled content is a valuable indicator, but a precarious one if not rigorously defined. Without traceability and standardisation of your suppliers’ data, the conclusions of a Life Cycle Assessment (LCA) may be invalidated. Your eco-design initiatives then risk being based on completely flawed premises.
It also presents an excellent opportunity to launch or strengthen your responsible procurement strategy. Demonstrating the ability to trace the origin of materials is a sign of control that is often valued in tender processes. Recycled content therefore emerges as a genuine driver of transparency and responsible procurement.
Why is calculating recycled content more complex than it seems?
Demonstrating a high proportion of recycled material is now a powerful selling point. This indicator is particularly in vogue because it addresses three major contemporary challenges: the growing pressure on critical resources, the search for a supply chain less vulnerable to global uncertainties, and the need to reduce the environmental impact of products.
It is a circularity indicator that is insufficient on its own to measure environmental performance, as it does not reflect the entire life cycle of a product — from the extraction of resources to its end of life.
The technical reality varies greatly depending on the type of raw material (metals, paper, plastics or oils). Whilst metals can be recycled indefinitely, the quality of paper and plastics deteriorates with each recycling cycle. This requires the systematic incorporation of virgin material to maintain performance. Furthermore, certain recycling or regeneration processes (particularly for oils) have an environmental impact almost as significant as that of processing virgin materials.
However, the main challenge is that the relevance and comparability of this measure depend entirely on the rigour of the calculation methods used.
To help you understand this better, this article examines the reality behind this indicator.
The key principles and framework of the ISO 14021 standard
The international ISO 14021 standard provides a strict framework for self-declared environmental claims. It imposes principles of transparency, verifiability and scientific rigour. This technical framework aims to limit the circulation of vague or misleading claims on the market.
To accurately measure recycled content, this standard distinguishes between the origins of material streams. It thus defines two distinct categories, each with a very different environmental value:
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- Pre-consumer materials: These originate from industrial or logistical waste diverted from the waste stream. This excludes the direct use of residues within the same production process.
- Post-consumer materials: These come from finished products generated by households or commercial premises. These goods have completed their initial use before being collected for recycling.
This distinction forms the essential basis for any compliant and credible environmental claim.
The vagueness surrounding pre-consumer materials: beware of artificial percentages
The standard retains a certain degree of ambiguity regarding pre-consumer materials. This lack of precision allows some manufacturers to claim very high recycling percentages. However, the environmental reality often turns out to be far more modest.
It is in the management of scrap that the ambiguity arises. Every process generates a systematic loss rate that manufacturers reintroduce into their production cycle:
- In plastic injection moulding and extrusion: Purge material, sprues and start-up scrap can account for up to 20% of the material used.
- In metallurgy and metal processing (extrusion, stamping): Sheet metal stamping plants can generate up to 50% in cutting scrap. In aluminium extrusion foundries, extrusion scrap (billet ends, cut-to-length offcuts) regularly accounts for 15% to 25% of the volume of metal melted again in a closed-loop system.
In practice, these companies simply reintroduce the natural losses from their own manufacturing processes. Under ISO 14021, they may consider that these losses are not utilised within the same manufacturing process if they require further processing or must be incorporated upstream of the process that generated them. This operation takes place either directly within the same factory or between two factories, whether or not they belong to the same company. This is a standard form of production optimisation and not a genuine recovery of external waste.
Key takeaway: When a manufacturer claims 40% recycled content, does this refer to the reintroduction of its own 40% of internal waste, or to a genuine supply of sorted external waste? Without rigorous traceability of the material balance and transparency regarding the scope of the declaration, it remains completely impossible to compare two products.
Industries are attempting to organise themselves to define standards:
- ASI (Aluminium Stewardship Initiative) – Norme de Chaîne de Contrôle
- Worldsteel Association – Wordsteel chain of custody guidelines
- RecyClass (Europe) – Recycled Content Certification Audit Scheme
Manufacturers: the challenge of data consistency and quality
Even though all these initiatives appear to comply with the ISO 14021 standard on the surface, a 50% RecyClass-certified recycled content (plastic) is not based on the same methodology as a 50% ASI-certified content (aluminium) or WorldStainless (steel).
Why is it so difficult to arrive at an overall calculation?
- Different ‘mass balance’ models: In the plastics and chemicals industries, mass balance sometimes allows for complex theoretical allocations (recycled plastic is purchased and injected somewhere into the member’s network, and is then virtually attributed to a product). In the metalworking industry, one generally follows much more direct and traceable physical flows of scrap metal.
- Tolerance regarding pre-consumption: What is considered ‘reusable internal offcuts’ (excluded from the calculation) versus ‘pre-consumption waste’ (included) varies from one sector to another depending on the flexibility of their sector-specific guidelines.
How can you still carry out your multi-material calculation?
For a company that assembles complex components, the calculation becomes a real headache. The process requires traceability of every material purchased.
To successfully carry out your overall calculation without adding unnecessary complications, you need to reverse the logic: do not let the industry sectors impose their rules; ask them for a neutral framework.
The assembler’s three golden rules:
- Define requirements regarding the nature of the materials used.
- Assess the reliability of the information provided by your business partners.
- Analyse the uncertainty and quality of the data provided by your supply chain.
Technical note: This verification work requires the same scientific rigour as gathering information for a Life Cycle Assessment (LCA).
