What if the plastic packaging in the world were replaced by a different material? A material that consists of renewable raw materials, decomposes naturally, is less harmful to humans and the environment and is still as efficient as the plastics we know today?
Sounds like a fairy tale? It is too.
Since pictures of plastic islands in the ocean have been around the world, since animals with plastic in their stomachs have starved to death, since governments have banned plastic straws and disposable plastic bags, it has been clear that people’s handling of plastic is a problem for the environment – and an alternative is needed.
In this mood, the so-called bioplastics have had a real lightning career in recent years. In 2018, around 2.1 million tons of bioplastics came onto the market. That is only about one percent of the total plastics production. But many companies base their future strategies on bioplastics. For example, they want to research plastics made from algae, and Lego wants to make their blocks out of sugar and sells cups and food storage bags made from leftover sugar cane. The industry itself is therefore predicting further growth, and production could increase by 15 percent by 2024.
A number of scientific studies are now questioning the usefulness of bioplastics. They investigate what effects – and side effects – bioplastics actually have. The results: Many bioplastic products primarily package advertising promises. For the environment or health, however, they are not a real alternative.
In fact, the problems start with the term “bioplastic”. It is not precisely defined, so companies can use it freely to promote their products. In general, this includes various types of plastics: Firstly, bio-based plastics that are made from renewable raw materials, for example from corn starch or cellulose. And secondly, so-called compostable plastics. Whether a plastic can decompose in nature – at least in theory – does not depend on the raw material, but on its chemical structure.
Anyone who wants to understand what effects maize plastic and co. Have on our health or the environment must therefore look at plastics on a chemical level. This is exactly what a research group from the Goethe University in Frankfurt and the Institute for Social-Ecological Research has now done.
The scientists examined a total of 43 products made from bioplastics that are already available in stores as products or packaging, including drinking cups, coffee capsules, disposable bottles, bowls for fruit or vegetables, garbage bags, chocolate packaging and wine corks. They carried out tests with bacteria and examined the products under a mass spectrometer to detect any toxic ingredients.
The result: around two thirds (67 percent) of the samples contained substances that are toxic to cells. 42 percent of the samples can cause oxidative cell stress, and 23 percent had testosterone blockers, which can affect the hormonal balance in the human body. In a previous study with conventional plastics made from fossil fuels, the researchers came to similar values. “These results show that the bio-based and biodegradable materials are by no means less of a concern,” explains study author Lisa Zimmermann.