How can companies reliably demonstrate how much recycled material a plastic product contains and where the recyclate comes from? At present, there is no recognised chemical or physical method that can precisely determine recycled content and recyclate properties in plastic products. Such claims therefore have to be substantiated indirectly by tracing materials along the supply chain. Certification schemes can provide this assurance – but they differ considerably in what they certify and how compliance with their requirements is verified.

A study commissioned by the German Environment Agency (UBA) identified 34 certification schemes operated by organisations based in Germany, elsewhere in Europe and beyond Europe. Ten were selected for in-depth analysis, including ISCC PLUS, RecyClass, the Global Recycled Standard (GRS), flustix RECYCLED – DIN-Geprüft, a certification scheme involving testing by DIN CERTCO, as well as schemes operated by organisations in France, Italy, Belgium and the United States.

Different schemes provide different forms of assurance

The certification schemes differ fundamentally in their scope and object of certification. RecyClass Recycling Process Certification, for example, targets operators producing recyclates through mechanical recycling. The Global Recycled Standard and the Materials Matter Standard (MMS), which was still a pilot version at the time of the study, focus on textile value chains and incorporate extensive environmental, social, health and safety requirements.

The OBP Recycling Subprogram has a different focus again. It addresses Ocean Bound Plastic: inadequately managed plastic waste that is at high risk of reaching the ocean, for example via rivers, wind or tides. Other schemes examined in the study certify the recycled content of end products or also cover chemical recycling processes.

Choosing an appropriate certification scheme therefore starts with a practical question: what needs to be verified? This might be the recycled content of a product, the origin of the recyclate, a particular recycling process, or compliance with additional environmental and social requirements.

RecyClass scores highest against the study’s criteria

To compare the schemes systematically, the researchers developed an assessment matrix comprising 75 indicators. These covered areas including traceability of recyclate origin, environmental requirements for recycling processes, auditing procedures, requirements for certification bodies, control mechanisms and procedures for dealing with non-conformities.

Using the weighting applied in the study, RecyClass Recycling Process Certification Level 2 achieved the highest score, with 162 points. It was followed by RecyClass Level 1 with 141 points, the Global Recycled Standard with 140, MMS with 135 and ISCC PLUS with 130 points.

This ranking should not, however, be interpreted as a universal measure of quality. The schemes have different objectives and cover different parts of the value chain. Moreover, the weighting of individual assessment criteria can be adapted to different questions. The suitability of a certification scheme therefore depends on the specific purpose for which certification is required.

Transparency is essential for robust assessment

The study also identifies substantial differences in auditing procedures and institutional arrangements. Some schemes require on-site audits and specify audit intensity and frequency in detail, while others also permit remote audits or provide less clearly defined requirements. Only a small number make provision for unannounced audits.

Transparency emerged as another important factor. Extensive documentation was publicly available for ISCC PLUS, OBP Recycling, RecyClass, SCS Recycled Content and LNE, or could be supplemented through cooperation with the respective scheme owners. For QA-CER, PSV and flustix RECYCLED, by contrast, the information available for the assessment was considerably more limited. A lack of information consequently resulted in negative scores for some indicators.

Rather than identifying a single “best” certification scheme, the study therefore provides a basis for making a more targeted choice: What needs to be verified, what requirements does the scheme set, and how is compliance with those requirements checked?