recently conducted study which focused on the identification and quantification of microplastics in final refined compost found no remains of used EN 13432 certified industrial compostable bioplastics. If correctly composted, their use does not contribute to the increase of microplastic pollution. 

Microplastics and their potential environmental and health impacts have been of growing concern in recent years. Compost produced from separately collected biowaste, which is increasingly contaminated with conventional plastics, has become a contributor to microplastic pollution as plastic remains can leak into the environment. 

Spanish researchers from the University of Alcala and the Universidad Autonoma de Madrid selected and studied the final refined compost of five industrial composting facilities on the peninsula over a five-month period. This also included four materials made from compostable bioplastics certified according to the European Standard EN 13432. The researchers selected two commercial bags from local markets, one wrapping film from a commercial food package, and specimens from the material Mater-Bi supplied by Novamont S.p.A. 

Although 10 to 30 plastic items per gram of compost were identified in the analysed samples, none of them were EN 13432 certified compostable plastics. In fact, despite “evidence that compostable plastics arrived in the composting plants at least as biodegradable plastic bags”, there were no traces of compostable plastics after the composting processes, proving the biodegradation of compostable plastics in industrial composting. The tested samples taken from the five composting plants use different collection systems. However