Contrary to popular belief, certified, industrial compostable organic waste bags neither bear harm for soil or human health, nor do they contribute to the problem of microplastics, as experts underline. On the contrary, they convey chances for a higher quality and quantity of collected organic waste. Read in the following a guest commentary by the Verbund kompostierbare Produkte e.V. (Association for Compostable Products / “Verbund”). 

For many years now, the German government has called on its citizens to perform thorough separation of their household waste. This includes especially organic waste, since the potential of this high value resource has been known for quite a while. Nevertheless, a recent analysis, carried out by the German Federal Environment Agency (UBA), revealed that the examined residual waste still contains almost 40 percent of organic waste. Although the reasons for this high level of misthrow may be diverse – revulsion towards organic waste and its unpleasant smells are certainly some of the most prominent.

In response to these challenges, compostable plastic bags for the collection of organic waste, as used in many other EU member states, have been available in Germany already for several years. Many waste management companies, municipalities and local authorities highly welcome the use of certified, industrial compostable bags, since their many benefits have been well-known and scientifically proven for more than a decade now. A clear advantage is the significant increase in the quality and quantity of separately collected organic waste and a corresponding rise in the amount of produced compost. However, as always, opinions are diverse, and misconceptions are quite common – both within companies as among consumers.

In view of recent misleading information, the Verbund highlights some of the many scientifically proven benefits industrial compostable organic waste bags offer to citizens but also the environment.

  • They significantly reduce the amount of conventional plastic in compost, as shown in a recently published study of the Witzenhausen Institute and the University of Bayreuth.
  • Large-scale experiments in Berlin, Milan, Munich, and other cities proved that, by using industrial compostable organic waste bags, the quantity of separately collected organic waste increased significantly.1

Just as the UBA states in this regard: “Unlike their paper-based equivalent, those bags are both durable and waterproof to a large extent, making the transport of organic waste more comfortable, even from apartments on higher floors. In a series of examinations, an increase of the amount of collected organic waste was achieved by using those bags. At the same time, the amount of conventional plastic disposed in the bio-bin was reduced”.

Stephan Kabasci, PhD, of the Fraunhofer UMSICHT affirms: “For many years, certified compostable organic waste bags have effectively supported the collection of organic waste in a number of European countries. Independently conducted studies have proven disintegration and biodegradation, both under laboratory conditions in line with DIN EN 13432 and in German composting sites. Thereby, it is ensured that certified compostable organic waste bags are no source for persistent fragments of microplastic within the environment”.

This statement is supported by the results of a study by ETH Zürich, which has shown that a polymer frequently used in compostable bags converted completely into CO2 and biomass, even under ambient temperature. It could be proven that the polymer carbon was partially incorporated into the microbial biomass, which is why it can be concluded that no microplastics have been created. As the research took place under ambient conditions in agricultural soil, one can assume that the biodegradation in industrial composting-sites, where perfect prerequisites are given, will take place even faster and more efficient.

“During the process of their certification, certified biodegradable products are, among other, tested for potential environmental risks by accredited testing laboratories. This examination includes – inter alia – tests for heavy metals and toxic effects to plants”, explains Oliver Ehlert, PhD, expert of DIN CERTCO, referring to conjectures about potential harms to soil and human health. “Furthermore, the recently established DINplus mark guarantees – in addition to the guidelines required by the ‘Seedling’ compostability mark following DIN EN 13432 – that these certified organic waste bags fulfil the demands of the value chain in Germany for shorter decomposing periods. The added value of independent certification has been discerned quite well by the legislator in the draft amendment of the German Organic Waste Ordinance”, Ehlert concludes.

Michael von Ketteler, Managing Director of the Verbund, states with regard to the amendment of the German Organic Waste Ordinance: “We are very pleased that the decision-makers trust the scientific data and are not swayed by false assertions.” The Verbund is convinced that the authorization of certified industrial compostable organic waste bags is one important key for encouraging more consumers to collect organic waste. After all, this is mainly a matter of motivation: “What we need is both better and more compost. Certified compostable organic waste bags, made of biopolymers, contribute to fulfilling the political objective of the ‘UMK’ (conference of all German Environmental Ministers): to reduce the share of organic waste in residual waste. Innovative solutions are required”, von Ketteler points out. “In addition, cleanliness and hygiene are vitally important for consumer acceptance.”

1 Kanthak, Manfred; Söling, Frieder: Bewertung des Einsatzes von kompostierbaren Sammelbeuteln aus ecovio®-Material. Müll und Abfall 8-2012, S. 402ff. & Ellen MacArthur Foundation: The New Plastics Economy: Rethinking the Future of Plastics. 2016, S. 33.