Five plastic bag materials from UK shops were tested to see what happened if they were left out in the environment.

All of the plastic bags disintegrated into fragments when out in the open air after 9 months however some of the ‘biodegradable’ plastic bags were still intact and able to carry shopping after more than 3 years buried in soil or in the sea.

Compostable bags were found to be a little better for the environment when left in the sea and disappeared after 3 months but were still intact in soil after 27 months.

Scientists at the University of Plymouth carried out the test and said the research has raised questions about biodegradable products being marketed to shoppers. If something is labelled as biodegradable people assume that it will be better for the environment but this may not always be the case.