Biodegradable and compostable plastic bags are still capable of carrying full loads of shopping after being exposed in the natural environment for three years, a new study shows.
Researchers from the University of Plymouth examined the degradation of five plastic bag materials widely available from high street retailers in the UK.
They were then left exposed to air, soil and sea, environments which they could potentially encounter if discarded as litter.
The bags were monitored at regular intervals, and deterioration was considered in terms of visible loss in surface area and disintegration as well as assessments of more subtle changes in tensile strength, surface texture and chemical structure.
After nine months in the open air, all the materials had completely disintegrated into fragments.
Read more at University of Plymouth