Many major cities and corporations are cracking down and banning plastic bags in an effort to reduce pollution and save our oceans. But is that really the best approach? While plastic bags are “almost certainly the worst” of all options in terms of ocean pollution, according to Quartz, the issue gets a little murkier when you take other environmental issues into consideration.

As it turns out, canvas tote bags might be less eco-friendly than plastic bags because they’re often made of cotton, which requires more energy and water to produce. According to one study from 2011, a cotton bag’s carbon footprint is 598.6 pounds of CO2, compared to 3.48 pounds for a standard plastic bag made from high-density polyethylene. Researchers concluded that it might actually be better to reuse those plastic bags you get from the supermarket, then recycle them once they’re no longer viable.

Similarly, a 2018 recent study from Denmark found that low-density polyethylene bags wreaked the least damage on the planet of all the different types of bag studied. (However, it’s important to note that ocean pollution was not taken into account in that particular study, and that plastic can still severely harm marine life and ecosystems.) Representatives of Denmark's Ministry of Environment and Food determined that conventional cotton bags would have to be reused 7100 times to match the cumulative environmental performance of a plastic bag. Organic cotton bags are even worse, because those would need to be reused 20,000 times.

So what’s a well-meaning, environmentally conscious consumer to do in the face of conflicting information? To start, Quartz recommends reusing your bags—regardless of whether they’re plastic or cotton—as many times as possible. And if you already own a canvas tote bag, be sure to actually use it to ensure you’re hitting the threshold needed to offset the environmental impact.

[h/t Quartz]