Biodegradable plastics found in fertilisers from composting plants
Researchers in Germany find a sizeable quantity of biodegradable plastic in commercially available compost.
A study at the University of Bayreuth, Germany, has found that finished compost from composting plants contains a large number of biodegradable plastic particles.
Composting plants process biowaste into finished compost, which becomes fertiliser for soils in fields and gardens.
The Bayreuth scientists discovered a significant number of biodegradable plastic particles that are smaller than 1mm. These made up 0.43% of the compost's dry weight.
While the German Fertiliser Ordinance requires that the proportion of biodegradable plastic in high-quality compost is a maximum of 0.1% of dry weight, it only applies to particles bigger than 2mm.
Despiute no legal or certification standards being broken, the researchers say their study questions whether biodegradable plastics are suitable as a replacement of conventional ones for environmentally and nutritionally sensitive processes.
The researchers say their scientific study is the first to systematically examine commercially available compost for biodegradable plastic particles, as they gathered evidence from four municipal biowaste recycling plants in Baden-Württemberg.