This is according to research from the italian Consortium for Collecting, Recycling and Recovering Plastic Packaging (Corepla), the Italian Composters Consortium (CIC), and Assobioplastiche, the Italian Bioplastic and Biodegradable and Compostable material Association.
The group collectively released a study that focuses on the effects of biodegradable plastics on plastics recycling streams in Italy, where all single-use carrier bags have to be compostable by law: the European standard EN 13432 since 2011.
The study confirms, according to the group, that mandatory collection of recyclable waste throughout Europe is necessary in order to improve the quality and quantity of plastics recycling.
Additionally, the group suggests that more investments in the modernisation of the waste management infrastructure are essential, including the implementation of separate mechanical and organic recycling streams.
The study: findings
Analysing the quality of recycled plastics from 19 waste sorting and recycling facilities around the country, Corepla found that compostable plastics only made up 0.85% of the plastic input.
Similar studies by the University of Wageningen show that there are no negative effects on the properties of recycled plastics containing starch film and PLA recyclates, the group says.
“Biodegradable plastics are designed to be treated in industrial composting plants. If they do enter mechanical recycling streams due to misthrows, they can easily be sorted out by available sorting technologies such as NIR (near infrared), as recent tests by the German research institute Knoten Weimar show,” the study authors explain.
Biodegradable and compostable plastics facilitate separate collection of bio-waste and help to divert organic waste from other recycling streams. Organic recycling is a well-established industrial process ensuring the circular use for biodegradable plastics while creating a strong secondary raw material market and opportunity for renewable energy generation.
Yet, the contamination of organic waste streams by misthrows of non-compostable plastics is high and constitutes a real problem for composting facilities and negatively affects the quality of compost, says the group behind the study.