It is now becoming increasingly clear that bioplastics are not the solution to all problems and can even lead to more problems. There are several reasons for this, which we would like to look at in more detail below:

• Bioplastics from food
  The plastics made from PLA mentioned above are currently the most criticised. They are made from food sources such as corn and sugar cane, which are also needed to feed humans and animals. As a result, bio-based plastic competes with human and animal nutrition, which is criticised by many opponents of bioplastics. Of course, these resources are sustainable and can be planted again and again, but this also comes at a high price. Fossil fuels are required for cultivation and the increased cultivation often leads to overuse of the soil. This leads to soil and water acidification. Additionally, biodiversity can be lost, which will have a major impact on the environment in the long term. Last but not least, fertilisers are frequently used during cultivation and pesticides often have to be used. For this reason, it is even assumed that the life cycle assessments of bioplastics and conventionally produced plastics do not differ from one another.
• Composting of plastics
  Difficulties arise not only in the production of biodegradable plastic, but also in its disposal. As previously mentioned, bioplastics require very specific conditions in order to decompose. For this to happen, it needs a certain temperature and sufficient oxygen and moisture must be available. Additionally, microorganisms or fungi must be present. Conventional compost at home does not fulfil these requirements, which is why you should never dispose of your bioplastic waste in it. Moreover, plastic is considered compostable if 90% of it has broken down into pieces smaller than 2 millimetres within 12 weeks (according to the standard DIN EN 13432). The problem with this is that normal biowaste decomposes much faster. This can lead to the quality of the compost suffering if the biodegradable plastic has not yet fully decomposed when the compost is used. In anaerobic digestion plants, most bioplastics also do not contribute effectively to biogas production, as they decompose poorly. For these reasons, bioplastics are often sorted out and incinerated together with conventional plastics, as it simply takes too long for them to decompose.
• The throwaway society
  We still live in a throwaway society. Advertising with biodegradable plastic can further reinforce this behaviour. Products are often advertised as ‘environmentally friendly’, ‘green’ or ‘eco’. This suggests to the consumer that the product can be thrown away without hesitation. It is not uncommon for them to be thrown carelessly into the environment. However, as previously mentioned, bioplastics only decompose under special conditions. If these conditions are not met, most bioplastics are just as difficult to degrade as conventional plastics made from crude oil. In this way, the use of biodegradable plastic can further exacerbate the problem of littering, as bioplastics cannot decompose in the oceans and waterways.