Question: how many times do you have to use a reusable bag?
Answer: A 2018 Danish study, looking at the number of times a bag should be reused before being used as a bin liner and then discarded, found that: polypropylene bags (most of the green reusable bags found at supermarkets) should be used 37 times. paper bags should be used 43 times. cotton bags should be used 7,100 times.