In 2019, the UK recovered 71% of single-use glass by mass, but only around 36% was used to make new container glass. This low circular rate is partly because the UK has a mixed collection system which requires the glass to be sorted into different colours before remelting and results in less cullet (waste glass for remelting) returned than in separated colour collection. Much of the glass is therefore used in aggregates for roads, resulting in nearly 50% of potential cullet not being used for new container glass bottles. The international nature of glass production and trade also means a large percentage of the bottles manufactured in the UK, particularly clear bottles, are exported for recycling, resulting in a loss of materials over which the industry has control.

These and other challenges to circular-loop recycling of container glass raise the question of why there are not large-scale national refill schemes for glass bottles in the UK. Such schemes were common historically but have greatly reduced worldwide in the last few decades.

TransFIRe researchers, Professor Steve Cinderby and Dr Jean McKendree, used User Journey interviews to explore the container glass industry perceptions, barriers and potential solutions for a national refill scheme for the UK.  Given that it is essential to have these key stakeholders on-board for any innovation to be successful, it is crucial to explore their perspectives in detail.

A small cross section of senior stakeholder representatives were recruited for interviews, all working within the glass industry on supply, production and sustainability.

These interviews revealed many regulatory, logistical, economic, social and industrial challenges to nation-wide refill schemes. The majority of challenges and solutions identified were within industries’ sphere of influence with exceptions around the need for clear legislation and behaviour change. There would be a need for clear legislation mandating the collection process and deposit scheme which are the responsibility of the four devolved legislatures. Additionally, behaviour changes would require the public to be a key stakeholder in the successful adoption of reuse.

A refill scheme would require all parties to act in coordination to introduce a cascade of changes including collection and storage processes, sorting, cleaning and relabelling. It is likely that only a subset of bottles could be refilled that use standardised bottle shapes, e.g. beer. Many logistical issues have technological solutions such as QR code labelling for tracking use, easily removeable labels or organic paint that won’t clog washing machines, or different coating methods to reduce scuffing. Embedded codes could also help reduce counterfeiting of standard glass bottle shapes.

Concerns were raised that consumers would be confused by the fact that some bottles could be returned and some recycled. Such confusions are already problematic for plastics and other materials in the UK, creating a need for expensive and time-consuming sorting or rejection of whole loads.

Stakeholders agreed that encouraging local return and refill schemes for certain product ranges could be an environmentally beneficial approach, reducing the transport costs significantly and creating local jobs. However, the distance between the bottling plant and the local distributor plays a key role in the impact – one study concluded that for distributers within a 200km range of the bottling plant, refillable bottles were far better in terms of environmental performance after only two deliveries, however, at distances of 800km there was no environmental benefit, even after 30 uses.

This suggests that local refill schemes may be viable and desirable for products that are produced in the area, such as milk or beer, but would depend on distance to refill sites for products such as wine or cosmetics.

However, there was also stakeholder consensus that given the high recyclability of container glass, it may be that investment in promoting colour-separated glass collection and increasing the recycling rate and in the UK to over 90% could be a cheaper, faster and more sustainable approach. There was also concern that unless processes are carefully balanced, return schemes may actually encourage more use of virgin materials because of the removal of waste glass from the manufacturing process.

Bottlenecks to glass return and refill in the United Kingdom: User Journeys to explore industry perspectives
Steve Cinderby, Jean McKendree
Sustainable Futures, Volume 7, 2024, 100197
ISSN 2666-1888,
https://doi.org/10.1016/j.sftr.2024.100197.