Biodegradable plastic is often offered as the solution for plastic that ends up as litter in the environment. Instead of fossil raw materials, biodegradable plastic is manufactured from natural materials, such as corn, sugar or various oils. However, despite the materials being renewable, bioplastic itself is not automatically biodegradable.
“End users are often given false information about bioplastic and its degradability. The general assumption is that by replacing fossil-based plastics with bioplastic, we can prevent problems such as littering,” says Johanna Kohvakka, director of the non-profit circular economy organisation From Waste to Taste.
Although bioplastic sounds green, the material is usually not biodegradable. Unfortunately, a biobased plastic bag thrown in nature acts in the same way as a plastic bag made from oil: it does not readily decompose.
And although some bioplastics are biodegradable, experts still see them as a poor solution for various reasons – the decomposition process is difficult to control completely and, at the same time, the material does not decompose quickly enough to be used as organic waste at waste treatment plants.
The greatest problem, however, is that biodegradable plastic cannot be recycled together with normal plastic. Should it accidentally end up in the bin with recycled plastic, biodegradable plastic may spoil the entire batch.