Why do we need bioplastics


However, not every plastic made from a renewable raw material is compostable. Conversely, not all compostable packaging is made from renewable raw materials. The share of bioplastics is still below 1 percent of the global plastics markets. In the foreseeable future, it will hardly exceed the order of magnitude of 2 to 3 percent, according to the result of a current analysis by the Institute for Bioplastics and Biocomposites (IfBB) at the University of Hanover.

Examples of bioplastics in the food market are, for example, disposable beverage cups made from polylactide (based on lactic acid). An international beverage company wants to have its PET bottles converted to the so-called PlantBottle, which is made from sugar cane, by 2020. Despite its natural raw material, this bottle will not be biodegradable. Biologically based plastics are also suitable for fruit and vegetables as well as baked goods, as they stay fresh longer because of the water vapor permeability of the material.

Manufacturers like to give their products an environmentally friendly image by labeling the packaging as "green" or "organic". Whether a bioplastic is to be assessed better than a conventional plastic from a sustainability perspective can only be decided on a case-by-case basis with meaningful life cycle assessments.

Valuable humus does not form when a bioplastic breaks down; at best it breaks down into carbon dioxide (CO2) and water. The plants required for bioplastics grow in monocultures, pesticides are also used and the land required for the renewable raw materials competes with the land used for food production. It should not be forgotten that a large number of additives are added to the production of bioplastics to achieve certain properties.

As with conventional plastics, a transition (from the packaging to the food - migration of substances) of these chemical additives or their degradation products into the food can take place. At present, however, the health effects cannot be reliably assessed.

Bio-plastic bags are also not suitable everywhere for collecting household compost. They often damage the quality of the compost and sometimes cause higher costs in the plants. However, if the compost waste from a municipality ends up in a bio-fermentation process, it is not a problem. The respective waste management companies should therefore provide information to the population.

Bioplastics must not encourage careless handling of packaging waste. The use of reusable products and the avoidance of packaged food are the better alternative.