Fact check No. 3: the complicated matter of bio plastics

In discussions about environmentally friendly types of packaging, it usually does not take long before bio-plastics are brought into the debate. It’s no wonder: “Organic” – that sounds sustainable after all. But there is something that is often overlooked: The ecological balance of bio plastic is not necessarily better than that of conventional plastics. For “bio plastic” is a collective term for a whole series of different materials. And each of them involves its own advantages and disadvantages.

The difference between bio and bio

The designation “bio plastic” is not protected and is therefore used for an extremely varied range of products. Most of them can be classified in one of two groups: in bio-based and in biodegradable plastics.

Biodegradable plastics decompose under certain environmental conditions to water and CO2. Depending on the type of material, this can occur quickly or it can take a very long time. But to produce beverage bottles, a material is required that remains durable – especially under damp conditions. This is one of the reasons why biodegradable plastics cannot be the sole solution for the worldwide waste problem. On the contrary: The EU points out in its strategy paper on the recycling economy that the designation “compostable” could even induce consumers to throw away packages carelessly – and make the environmental situation even worse.

According to the German Federal Environmental Agency, even recycling in industrial composting plants is not the most sustainable way to dispose of plastics. As bio plastics mainly decompose to water and CO2, they do not contribute to the formation of humus or fertiliser. The Research Services of the German Bundestag therefore find it to be ecologically more sensible to either use them for material recycling or at least to incinerate them for energy generation. However, in both cases conventional plastics prove to be considerably more efficient.

Bio-based plastics are not manufactured from crude oil, but instead from renewable resources. When considered individually, that is a sustainable approach. However, when the entire life cycle is considered, then bio-based plastics often have no ecological advantages, in the judgement of the Research Services of the German Bundestag. The reason: They are often produced from food crops cultivated especially for this purpose, such as maize, potatoes or sugar cane. In addition, cultivation is generally not carried out biologically, but instead with energy-intensive methods and using polluting pesticides and fertilisers. The ecological balance is a little better for those bio plastics produced from agricultural or forestry waste. But even these are – at least for the time being – not more sustainable than conventional plastics that are produced with energy-saving technologies and are held in a material cycle.


… and what does that mean now?

Bio plastics are not per se sustainable – for two reasons:

  • There are a large number of bio plastics, each with different properties.
  • The environmental balance of each individual plastic results from a complex interaction of individual influencing factors – some of them positive, some of them negative.

The greatest difficulty here: To get a handle on the global waste and resources problem, a material is required that

  • meets the technical requirements of the manufacturing industry,
  • can be produced in sufficient quantities and disposed of at a reasonable cost and
  • provides ecological advantages.

However, none of the bio plastics available today could completely fulfil all three requirements for beverage packages. Of course, research on this subject continues and may still reveal the ideal material. But there’s no reason to just stand by waiting for that to happen. For existing materials like PET can already be produced in a resource-saving manner and kept in a closed circuit today. The technologies and the know-how for a sustainable use of plastics are already there – we just have to introduce them into the world more and use them consistently.


Worldwide production volumes

Bio plastics

  • 2016: 4.2 million tonnes (= 1 percent of total plastics production)
  • 2021: Estimated 6.1 million tonnes

Plastics in general:

  • 2017: 348 million tonnes, of that one-sixth in Europe


Let´s talk facts: Does Krones offer a sustainable solution for the packaging market? Yes – and not just one, but a whole lot. You can read what these are in the next fact check!