Manufacturing
Plastics converters and recycled content
Claiming a recycled percentage is easy; supporting it with documentation is not.
A converter lives between two demands pulling in different directions: customers want more recycled material, and at the same time want the product to keep meeting the same requirements. On paper, those two things rest on different documents and neither covers the other.
The three declarations that are not interchangeable
| Declaration | What it asserts | What supports it |
|---|---|---|
| Composition and performance | What the material is and how it behaves | Your resin supplier, per reference |
| Suitability for use | That it fits the intended application | Your supplier and, depending on use, you |
| Recycled content | What proportion comes from recovered material | Your intake traceability, not a promise |
Important
The third is the most asserted and the worst supported. A recycled percentage **is not a product characteristic: it is the result of a balance between what came in and what went out**. If you cannot reconstruct which material went into which production run, the figure you give is an estimate — and the moment a customer audits it, that distinction shows.
What you must be able to show
- 1
What material came in, from whom and with what documentation
Including recovered material, which arrives with the poorest paperwork.
- 2
What was produced from what
The link between intakes and outgoing batches, as in any traceability.
- 3
The criterion used to calculate the percentage
Written once and applied identically: varying it between customers gets detected.
- 4
And what happens when the supplier changes
Another resin is another reference, and it drags new declarations with it.
Watch out
The point that surprises on a supplier change: even with equivalent material, **declarations follow the reference and are not inherited**. Switching resin on price or availability is a purchasing decision that drags technical documentation, and if nobody tells whoever maintains the declarations, your finished product quietly loses its backing with nothing visible changing.
When the end use is sensitive
Worth knowing
Which frameworks apply to each use, what may be declared and with what backing depends on the product, the destination and the market, and it gets updated. **Before committing to a percentage or a use in an order, confirm with your adviser or the resin manufacturer**; this only explains what documentation exists and what each asserts.
›Does the supplier's declaration support the percentage?
It supports what they supplied, not the balance of your production.
›What if we blend batches of different origin?
Then the calculation criterion is what must be written down and applied consistently.
›How long must it be kept?
Whatever the end use requires, with margin: in packaging, longer than the life of the product it holds.
A real case
The situation
A converter offers a recycled percentage and a customer asks to audit it.
What you do
- Reconstructs the balance from intakes and outgoing batches
- Writes down the calculation criterion and applies it uniformly
What you get
It can sustain the figure in the audit instead of admitting it was an estimate.
The situation
The recycled content is declared with no backing.
What you do
- Stores what backs it with the reference
What you get
The declaration holds up.
The situation
The supplier changes the blend and nobody knows.
What you do
- Asks them to communicate any change
What you get
The change arrives before the question.
The situation
A client asks you to evidence one specific run.
What you do
- Checks that production run's file
What you get
You answer per run.
The situation
Intakes from different suppliers get mixed.
What you do
- Records what went into each run
What you get
You can say what came from where.
The situation
The supplier's documentation expires.
What you do
- Records expiries per supplier
What you get
The warning arrives before producing.
This article answers
- recycled content documentation
- food contact declaration for plastics
- changing resin supplier
- evidencing recycled content