The research was conducted by the International Marine Litter Research Group of the University of Plymouth. For the first time, they have tested how long plastic shopping bags behave after prolonged exposure to the sea, oxygen and earth. In addition, several bags with the claim ‘compostable’ or ‘degradable’ compared to a conventional plastic bag.
No bag completely fell apart in nature. However, the compostable bags performed better than the ‘biodegradable’ bags. When exposed to seawater, they disappeared within three months. However, further research is needed to determine whether residual products are left behind and which. The compostable bag remained in the soil after 27 months, but it tore after researchers tried to use it. The so-called biodegradable bags may have looked unpleasant, but after three years they were just as strong as a conventional plastic bag. It raises the question whether entitlements such as ‘(oxo) biodegradable’ are a reliable indicator of the degradability of packaging materials in nature. They seem offer little or no solution for reducing the plastic soup in the oceans.
The research has been published in the scientific journal Environmental Science & Technology of the American Chemical Society.