According to a 2009 study led by Associate Professor Karli Verghese from the School of Architecture and Design at RMIT about the environmental benefits of various types of bags, the number of times you would need to use a reusable bag to have any impact on the environment is surprisingly high.
Reusable bags in general need to be reused at least 50 times in order to have any benefit, however the green polypropylene bags you buy at the supermarket will actually have a greater impact on the environment than plastic bags if they’re only reused 52 times.
Verghese claims that the number of times you need to reuse your green bags is 104, or weekly for two years for them to have any benefit.
Given most people are guilty of going to the shops and, having forgotten to bring their green bags, buying new ones thinking it’s better than plastic bags, it’s something worth keeping in mind.
This article originally appeared on Starts at 60.