For years, the waste management industry claims that bioplastics can cause a serious disturbance in the established recycling streams such as PE and PET.
In the UK in particular, the British Plastics Federation’s Recycling Group (BPFRG) have been warning the government about the compromising effects of biodegradable bags on the entire waste stream in response to a government proposal to exclude biodegradable bags from UK’s planned carrier bag tax.
According to BPFRG, biodegradable plastics of whatever kind cannot be recycled along with conventional plastics without “catastrophic effects.” The group pointed out a study done on single use bags in Wales and Ireland where biodegradable bags are included under the Irish bag tax legislation. BPFRG said an exemption from the bag tax should be given to bags with a high plastic recycled content, instead, as these could be recycled readily again and again.
BPFRG emphasized that an exemption of biodegradable bags in the bag tax could lead to a large contamination of the conventional plastic waste stream, which could ruin the integrity of recycled plastics.
In response, the trade association European Bioplastics released a study in December stating that up to 10% compostable plastics (such as PLA, PBAT, starch blends) mixing with conventional plastics in post-consumer recycling streams show no or negligible impact on the mechanical performance of the recyclates.
Compostable plastics have its designated organic recycling marked with logos such as the Seedling. However, in the event that compostable plastics end up in recycling streams, the prevalent sorting technologies are able to sort them with little residual waste, and that studies and field trials have demonstrated this, according to independent studies of the Institute for Bioplastics and Biocomposites (University of the Applied Arts and Sciences Hannover), the Italian National Packaging Consortium (CONAI), and the company Biotec.