After 180 days the bags had not degraded but fragmented into smaller pieces, generating microplastics, and biofilms colonized the surface almost immediately. The authors conclude the oxy-biodegradable label is greenwashing and warn biofilms could carry pathogens.
Researchers at the University of São Paulo submerged oxy-biodegradable HDPE shopping bags in river water for 180 days to test whether they degrade completely as labelled. They tracked chemical and physical change with FTIR spectroscopy and scanning electron microscopy, and monitored microbial colonization.
