Why 'bags for life' could be carrying germs
29 October 2013 Last updated at 12:48 GMT
In the past few years shoppers have been encouraged to switch their disposable plastic bags for so-called "bags for life" - in order to help the environment.
But health experts have now warned that using the same bag to carry raw meat and soil-covered vegetables increases the risk of food poisoning.
Hugh Pennington, emeritus professor of bacteriology at Aberdeen University, warned that even meat which is wrapped in plastic could harbour harmful bugs.
The professor told BBC Radio 5 live's Drive: "Washing the bag is not a very good idea - you can't be certain you've got rid of all the bugs. For any bag that's has raw meat in it, I would recommend that bag is disposed of."