In order to make the plastics value chain truly circular, it’s crucial that the industry is able to measure the level of recycled content in packs accurately and efficiently. Researchers from Manchester University in the UK are currently developing a technology that uses tracking molecules for identifying, quantifying and validating recycled content in plastics and plastic packaging. We spoke with Prof. Mike Shaver, who is leading the project, to find out more.


I think it’d be useful to situate your innovation in the context of the wider packaging sustainability landscape in Europe. Broadly speaking, what is the importance of measuring the level of recycled content in plastic polymers?

Pollution resulting from plastic mismanagement is a major threat to our planet’s natural environments and our way of life. The EU plastic recycling rate sits at a subpar 3, with the majority being used only once and then landfilled, littered, or incinerated. An even smaller fraction of recycled plastic sits within closed-loop frameworks for conversion back to use for similar-quality applications.

The incorporation of recycled plastic, also known as post-consumer resin (PCR), into products is one of the most effective ways of reducing greenhouse gas (GHG) emissions associated with production. For example, adding 30% PCR in PET packaging.

In response to rising environmental and socioeconomic pressures, governing bodies in the EU and UK are setting targets through new legislation to promote increase recycling. The earliest of these comes in April this year when the UK will introduce a tax (£200/tonne) on plastic packaging that incorporates less than 30% PCR content.

A similar EU Plastic Packaging Levy will come into force soon, at an even steeper cost (€800/tonne). At present there is a distinct lack of reliable analytical approaches to verify recycled content of plastic products and waste, meaning these ambitious legislations largely rely on honesty in product formulations that have a longstanding lack of transparency. We’re concerned this will lead to greenwashing and, at worst, fraud.

How has the level of recycled content in plastic products historically been measured, and as you see it, what are some of the inherent drawbacks of these methods?

The ‘mass balance’ approach has historically been used to track movement of recyclate feedstocks in and out of production facilities and across supply chains and remains by far the most common method. Mass balance is an indirect method to track volumes through the production system, rather than a quantitative means of measuring PCR content in a specific item of packaging.

There is considerable dissatisfaction with the mass balance approach for plastics by many in the industry and in government. This is because, while it may show that a company has acquired or produced and used certified amounts of recycled materials, it does not show how (or even if) the recyclate is used. Mass balance is also very onerous, is paperwork heavy and financially taxing, and requires significant effort at each step in a supply chain.

Alternative methods proposed for PCR content quantification are inconsistent when you try to apply them to different plastic types or processing histories. Plastic polymer characteristics before and after recycling are heavily influenced by processing conditions (e.g. temperature) and the additives used to mitigate property loss. Reliable comparisons of pre-and post-recycled polymer MWs would require standardisation of polymer feedstock, processing conditions, additive formulations and equipment across the industry. However, with a packaging sector dominated by trade-secret recipes and little transparency, the standardisation of (re)processing remains impractical, and a process-independent PCR quantification method is needed.

Could you talk us through how the innovation itself actually works, and give us some background into the project?

This is a bit technical, so please forgive me! Our innovation makes use of a molecule – let’s call it ReCon2 – that exhibits a unique fluorescent response when placed under UV light. It is easily added in minute concentrations into a plastic recyclate stream during compounding.

When this recyclate is blended with virgin plastic we can rapidly measure a change in the molecular nature during this dilution, giving us a quantifiable analytical measure from 10-100% of recycled content. We have now demonstrated at lab scale the ability to quantitatively determine the recycled content of marked batches of three of the most widely used packaging plastics (HDPE, PP and PET), together encompassing 40% of total EU plastic use.

ReCon2 is suitable for application in industrial recycling facilities because its fluorescence signal is independent of plastic processing conditions, sample size, is unaffected by additives and pigments and negligibly impacts the thermo-mechanical properties of the marked plastics. ReCon2 has already been assessed as safe by the FDA and REACH and has been used in food contact applications.

Developing a robust technology that avoids laborious effort and cost will encourage compliance over fraud and help rebuild public and corporate trust in recycling.

Were there any key challenges/roadblocks that had to be overcome during the R&D process?

I think the biggest challenge was in making the leap from measuring a concentration of something to a molecular change. The idea was the key step forward. However, there have been lots of other smaller challenges along the way in understanding how this technology would work in a supply chain.

And we still have some way to go to get to a fully robust system. Understanding how to situate our technology within the packaging sector has also taught us a lot about technical barriers to packaging development and common perceptual barriers in the industry.

The biggest non-technical tests of our resilience over the past 12 months have been caused by the ongoing restrictions associated with the pandemic which were compounded by our recent relocation to the Sustainable Materials Innovation Hub, situated within the Henry Royce building at the University of Manchester.

My fantastic team members in Zoé Schyns and Thomas Bennett have taken the lead in the lab and have been instrumental in bringing ReCon2 to where we are today. I think we’ve been more agile because our team is still in miniature.

What’s next for the project? Are there any plans to level up and test the innovation at scale with commercial partners?

We’re at the exciting stage of spinning out from the University of Manchester, but not in the traditional way. We’re launching as a not-for-profit entity with support from the University of Manchester’s Innovation Factory. We expect 2022 will be a big year for us with the implementation of the UK government’s plastic packaging tax legislation. We’ve recognised that the Plastic Packaging Tax isn’t nearly ambitious enough to incite change, so we are working with external partners to develop and launch a “trust mark” that can be printed on product labels to inform customers of the packaging’s recycled content, which will be underpinned by our technology.

This can then also be used to report on the plastic packaging tax. The market and potential for growth of this technology is massive if things continue to progress; the EU used approx. 20 million tonnes of plastic packaging in 2022.

Our more immediate next steps are to conduct a large trial with some early adopters who want to be on the front end of this change. This includes recyclers, packaging producers, brand owners and grocery chains delivering major trials (1 tonne) and blind testing to show what is possible. We’re working with the ERDF support in the Sustainable Materials Innovation Hub to scale up ReCon2 masterbatches. We’re always interested in growing our community, and so this is the right time to explore next steps with us.