Certification and Chain of Custody: The Evidence Behind a Percentage

A recycled-content claim is only as strong as the chain of certificates beneath it. Three scheme families do most of the work in Europe. EuCertPlast certifies recycling plants and the recycled output they produce, including its post-consumer origin. RecyClass provides recyclability assessment and recycled-content certification for plastic products and packaging, with traceability through the converting chain. ISCC PLUS certifies chain of custody for circular and bio-based feedstocks, including the mass-balance bookkeeping chemical recycling needs. A packaging manufacturer's file typically stacks them: recycler certification at the base, custody certification through each trade, and the manufacturer's own allocation records on top.

The schemes differ in what exactly they attest. Confusing their scopes - treating a recyclability certificate as a content certificate, or a site certificate as a consignment guarantee - is the characteristic evidence error of early programmes.

For every certificate in a file, three checks. Scope: does it name this material, this process and this site - a group certificate covering 'European operations' invites the follow-up of which site produced this consignment. Validity: is it in date across the period the material was produced and supplied, not merely today? Chain continuity: does each hand the material passed through hold custody certification covering its step, or does the chain have a gap where the claim becomes an assertion? Certificates should be re-verified on their renewal cycle and on any supplier change, and the verification itself dated in the file. The exercise takes minutes per certificate and is the difference between evidence and decoration.

Not all content evidence is third-party certified, and the methodology may recognise supplier declarations for defined cases - particularly simple mechanical chains with full documentation. The hierarchy of credibility runs: certified chain, then audited declaration, then bare declaration. Match the evidence to the exposure: flagship lines, public claims and borderline percentages deserve the top of the hierarchy; trivial components deep inside a unit may honestly rest lower. What is never acceptable is a percentage whose evidence nobody can name. If the file cannot say where a number came from, the number is not yet a compliance figure - it is a hope with decimals.

Expect an auditor to sample a content figure and walk it: from the unit's calculation, to the manufacturer's allocation record, to the converter's custody certificate, to the recycler's output certification and its post-consumer basis. Each hop is a document produced in the ordinary course, dated within its validity, naming the material in question. Breaks are usually mundane - an expired certificate renewed late, a certificate in the parent company's name for a subsidiary's site, a scope that names the resin family but not the grade actually bought. All are preventable by the scope-check routine above, run on a calendar rather than on the eve of the audit.

Certification is digitising: scheme registries with verifiable certificate status, transaction certificates per consignment, and - on the horizon - the digital product information architecture the labelling station describes. The direction of travel is toward verification at data speed, where a claim that cannot be resolved against a registry in real time ages badly. Businesses building content data systems now should store certificate identifiers, not PDF scans, as their primary key: the identifier resolves to live status; the scan resolves to a filing cabinet.

The stack decision per line turns on three facts: the feedstock route (mechanical chains and chemical chains certify differently), the claim's exposure (a percentage printed on pack demands the top of the hierarchy), and the customer's own requirements, which in retail supply chains increasingly name the schemes they accept. Map the line against the three facts once, record the chosen stack in the file, and review it when any fact changes. Schemes evolve - recognition decisions under the methodology may elevate some and marginalise others - so the stack is revisited at each implementing-act milestone in the timeline station's calendar rather than treated as settled at first purchase.