A new report by the non-profit Zero Waste Europe (ZWE), commissioned to Eunomia Research and Consulting, has identified the main obstacles to the circularity of single-use glass ahead of a revision of the Packaging and Packaging Waste Directive (P&PWD).

Glass bottles

According to ZWE, the collection stage is where the most considerable loss of glass material occurs, which it describes as ‘a huge resource and environmental loss’.

The study, titled ‘How Circular is Glass? A report on the circularity of single-use glass packaging’, explores the current circularity of single-use container glass by examining the mass flows of single-use glass packaging in four countries – Germany, France, the United Kingdom and the United States.

In turn, it highlights the key limitations to circularity which include ineffective collection methods, design, and logistical shortcomings – all of which ‘lead to material and energy losses’.

To assess and calculate the circularity in each of the country's case studies, the report uses four key performance indicators, determined by data from 2019. These indicators are collection rate, overall recycling rate, closed-loop recycling rate, and recycled content.

Although losses from the circular glass system occur at three stages – in collections, during sorting and when the cullet is distributed to different recycling end markets – the most significant losses of glass material occur at the collection stage.

For instance, findings from the US case study show that over half of its glass packaging placed on the market (56 per cent) is not collected in recycling. In both the French and UK case studies, up to 30 per cent of lost glass material was reported. In Germany however, only 19 per cent of glass packaging is not captured in recycling collections.

From the report, it is also apparent that net glass packaging exporters have considerable differences between their ‘close-loop recycling rates’ and their recycled content rates. As ZWE presents it, this is because ‘exported glass packaging escapes the local collection system’ and shipping cullet for long distances is uneconomic.

Two main collection methods are called attention to within the report – co-mingled collections (where glass is collected with other types of packaging) versus separate collections (glass collected in a separate stream from other packaging), and colour-separated collections versus mixed colour collections.

By comparing each country's overall recycling rate to its closed-loop recycling rate ZWE found that those that rely ‘predominantly on co-minged collection systems’, such as the UK and the US have less cullet returned into glass manufacturing than those that use a separate collection stream for glass. The UK and the US have respective co-mingled collection rates of 55 per cent and 53 per cent.

In Germany and France, glass collected co-mingled is ‘less than one per cent of the total collected tonnages’, ZWE says. For this reason, only two per cent and nine per cent of the sorted cullet respectively is used for recycling applications other than container glass – whereas, this figure reaches 40 per cent in the UK and 39 per cent in the US.

ZWE proposes that ‘a well-designed’ nationwide Deposit Return Scheme (DRS) that includes single-use glass could improve the overall glass collection rates if implemented across Europe. Existing DRS systems currently achieve up to 89 per cent collection rates for glass beverage bottles, the organisation says.

From this, the report concludes that the most glass packaging going through a high-quality separate collection system, such as a DRS, the ‘more glass is likely to flow back into the manufacture of new single-use glass’.

ZWE is urging the European Commission (EC) to make use of its findings in the upcoming revision of the P&PWD. In line with this, the non-profit is asking the EC to:

• Mandate the implementation of DRS that will include single-use glass packaging, charges reasonable deposit fees, and offers a well-designed infrastructure
• Improve logistics by encouraging bottling in beverage importing countries, with the aim of ensuring that glass container bottles are recycled and reused/refilled in the same geographical area
• Mandate the implementation of reuse targets through the introduction of efficient refillable systems – involving optimised infrastructure and reverse logistics, a suitable incentive to return, a high number of refill cycles, and operated under well-managed pool systems.

Larissa Copello, Consumption and Production Campaigner at Zero Waste Europe, said: "The P&PWD revision should act on the findings of this report by not only improving the circularity of single-use glass, but also by scaling up more refillable glass packaging systems across Europe and thus helping to tackle the current energy crisis.

“This can be done, for instance, by including effective closed-loop recycling via deposit return schemes (DRS) which include single-use glass; and by increasing the market shares of refillable glass packaging via strong reuse targets. We cannot ignore the truth about the single-use of glass anymore: its massive energy consumption during primary production puts single-use glass at the top of materials with the greatest environmental impacts. Yet, these are not justified, since this material is perfectly suited for reuse and recycling.”