Composting plants process biowaste into finished compost, which ends up as fertiliser in the soils of fields. A study by the University of Bayreuth shows that finished compost from composting plants in Germany contains a large number of biodegradable plastic particles. Applicable legal and certification standards are not violated by the sizes and quantities of the particles detected. However, the data published in „Scientific Reports“ call into question the contribution of these standards to effective environmental protection. They draw into question whether biodegradable plastics are suitable for replacing conventional plastics in environmentally and nutritionally sensitive areas.