How useful are PET bottles?

Plastics are the target of heavy criticism. High CO2 emissions during production, ocean pollution, disposable products. But the benefits of plastics are apparent, for instance, in the field of packaging used for drinks. PET bottles reliably protect their contents while hardly weighing anything at all. And that produces far fewer emissions during transport than the use of glass bottles, particularly over long distances. But it’s important to limit the detrimental effects as much as possible in order to make these benefits that the material has to offer count even more. So the approach taken by the Schwarz Group in Germany looks promising.

The group includes, among others, the Lidl chain of supermarkets. The stores also sell their own brands alongside the well-known brand-name products and these are sold exclusively in single-use PET bottles. A deposit is levied on such bottles in Germany, which means that the bottles are frequently returned to Lidl’s stores from where they are sent on to Prezero – a waste and recycling service provider, which is also a member of the Schwarz Group. The group has in this way established a material cycle that has resulted in more than 60 articles from its ‘Saskia’, ‘Freeway’ and ‘Solevita’ own brands of drinks being available in recycled bottles since 2021.

Disposable PET bottles are – besides their qualities that help protect their contents – also convincing where their carbon footprint is concerned. The low weight of recycled PET (rPET) means that its use reduces CO2 emissions by around 20% during the manufacturing and transportation of recycled bottles than comparable multi-use PET bottles do. That figure almost hits 50% when compared with 0.7-litre multi-use bottles made from glass.

The emissions produced by transport after use also need to be taken into account. A conventional truck, for instance, is only able to transport around 15,000 returnable bottles at a time, be they full to retailers or empty to bottlers. But, the study revealed that, once they’ve been pressed, as many as 400,000 bottles can fit on a truck. That in turn eliminates the need for around 26 truck journeys for each return transport.

The study is, however, not without its critics. The Deutsche Umwelthilfe (DUH – Environmental Action Germany) NGO, for example, has criticised the fact that the study does not compare the specific ‘Lidl plastic’ with the values from a specific bottling company that is working with multi-use bottles and that it has rather arrived at its findings on the basis of market averages. In the opinion of Barbara Metz, Managing Director at the DUH, that’s like comparing apples with oranges. The study also failed to mention the fact that every recycling operation produces two to five percent material shrinkage that needs be replaced from other sources.

“Lidl uses other market players and sources old single-use plastic bottles from them to top up the quantities lost during the recycling process. But that means that those companies must turn elsewhere to replace that material. And they generally resort to fossil-based new plastics to do so. That makes Lidl’s claim of 100% recycling a farce,” says Thomas Fischer, Head of Recycling Management at the DUH. The study’s authors had in fact themselves pointed out that the Lidl approach could not be easily transferred to other companies or the drinks industry as a whole.

But that did not affect the efficiency of the established system. Or that the Schwarz Group could play a pioneering role with its system of recycling. Because, while in Germany the comparison with multi-use systems is still useful, such systems would first have to be introduced on a sustainable basis elsewhere. PET, on the other hand, is among the most widely used material for bottles in the world. Much would already have been achieved if other distributors were to use recycled bottles in their operations.