He came from an American family of artists: father, two sisters, brother – all artists. Nathaniel Wyeth, however, struck out of style, technology fascinated him. As a child, he disassembled clocks and tin cans to make toys. He studied mechanical engineering, was hired as an engineer by the chemical company Du Pont in Wilmington/Delaware and was there in the late 1960s looking for the answer to a question: Why do bottles made of the plastic polyethylene terephthalate (PET) burst when you fill them with carbonated liquids filled?
Exactly 50 years ago, Wyeth made an invention that triggered a revolution in the beverage industry – and caused environmental policy debates. The engineer, who died in 1990 at the age of 78, developed a PET variant that can withstand the pressure. In 1978, Coca-Cola was the first manufacturer to fill its drink in such bottles – initially only in two-liter containers, which were technically the easiest to produce. Nowadays, PET bottles in all imaginable sizes are the global standard for bottling, especially soft drinks. Simply because they are easier to transport due to their significantly lower weight compared to glass.
In 2019, 18 billion PET bottles and their contents were sold in Germany. To the chagrin of environmentalists and politicians who warn against plastic waste and microplastics. The right take-back system is also the subject of critical discussion: disposable or reusable? The question of which system is more ecological and climate-friendly is not (any longer) so easy to answer.
However, the political mainstream is clear: as part of an amendment to the Packaging Ordinance, the EU Commission wants to drastically increase the proportion of reusable packaging for beverages on the European internal market. The federal government is moving along – the reusable share is to be increased from the current 43 percent to up to 70 percent. In the coalition agreement between the SPD, the Greens and the FDP, “ecologically advantageous reusable return and deposit systems” are set as a goal. The Federal Environment Agency supports the traffic light coalition in this position.
After Easter, Federal Environment Minister Steffi Lemke intends to present concrete proposals, and even a requirement for reusable offers for retailers is being considered. The attitude of the green environment minister and her house is clear: “Basically, returnable bottles are to be preferred because they can be used several times and thus save waste every time they are refilled,” says a spokesman for the ministry. A returnable PET bottle is reused up to 25 times and a returnable glass bottle up to 50 times. “This contributes to both climate protection and resource conservation.”
But is the calculation really that simple?
Visit to the Schwarz Group, which owns the retail chains Lidl and Kaufland, as well as a production company, which in turn is one of the largest food manufacturers in the country, including mineral water and soft drinks. The family company sells about 3.3 billion liters of beverages in PET bottles a year, about as many as Coca-Cola. It was the Green Environment Minister at the time, Jürgen Trittin, who introduced the deposit for cans in 2002 and with it a return and deposit system for plastic bottles. “We did what he rightly asked for at the time,” says Wolf Tiedemann, board member for sales and logistics at the discount chain Lidl. “Namely created a cycle through which the bottles can be kept in circulation. We have invested several hundred million euros in this.” The Lidl parent company Schwarz operates two recycling plants in Neuensalz in Saxony and in Übach-Palenberg in North Rhine-Westphalia. There, the one-way bottles returned by consumers are melted down and processed into recyclate, from which new bottles are made. Without adding new PET, as the company emphasizes.
“98.5 percent of all plastic bottles from the German deposit system are returned,” calculates Jörg Aldekott, CEO of Schwarz Production. “All mineral water and soft drink bottles are processed 100 percent into new Saskia and Freeway bottles.” On top of that, in the past ten years alone, the weight of a 1.5-liter PET non-returnable bottle has been reduced from 38 to 24.5 grams. The “blanket stigmatization of PET one-way systems like ours is not justified. Our system is not only equivalent, but in the overall ecological balance it is even better than reusable in some cases,” says Aldekott.
Lidl has commissioned a study on the subject
This is confirmed by a previously unpublished study by the Heidelberg Institute for Energy and Environmental Research (Ifeu) commissioned by the Schwarz Group. Accordingly, their 1.5-liter PET non-returnable bottle is better in terms of the overall ecological balance than comparable reusable bottles. Although their melting down requires energy, the return transport from the supermarket or discounter alone is more climate-friendly. A truck can transport around 400,000 compressed non-returnable bottles, but only 15,000 returnable bottles. In order to transport 900,000 returnable bottles, around 26 truck trips are therefore necessary. Conversely, far fewer full returnable bottles than one-way bottles fit on a truck. In the overall balance, a one-and-a-half liter reusable bottle with a CO2 equivalent of 32 kilograms per 1000 liters of filling material is more climate-friendly than commercially available reusable bottles (41 kilograms), according to the Ifeu experts.
Aldi makes a similar argument and also refers to a return rate for PET bottles of almost 100 percent. However, the Federal Environment Ministry is reacting cautiously and is sticking to its previous position. The energy and resource consumption for the return transport and cleaning of reusable bottles is “usually lower than the additional production costs for disposable packaging,” says a spokesman. “This applies all the more, the more regional the distribution and the higher the number of refills.” He indirectly doubts the argumentative power of the Ifeu study. “In order to compare the ecological effect of disposable or reusable variants, manufacturers or retailers often have life cycle assessments drawn up.” However, it is “very much dependent on which evaluations and assumptions are used as a basis for the respective systems, so that they are really generally applicable”. Therefore, “a direct comparison of different types of packaging is often very difficult,” said the spokesman.
However, to dismiss the black numbers as pure tweaking and lobbying would be too short-sighted, especially since environmental organizations also like to argue with commissioned reports. However, a technical and political dialogue with the aim of finding the indisputably most climate-friendly system is not getting off the ground between politics and trade. At least that’s what the food industry complains about. Out of the feeling of not being heard by politicians, Lidl is planning an information campaign about its own one-way system after Easter. “We just want our facts and arguments to be heard and included fairly in the political assessment,” says Tiedemann. Namely in relation to the overall ecological balance. “We would very much like to face the fact check.”