evidence: Many traditional tea bags contain a small amount of polypropylene, which is often used in heat-sealing methods but can release microplastics when heated. [...] It’s simple, really. The brand shouldn’t have any microplastics in their tea bags. Sadly, the requirement isn’t as straightforward as we’d like. [...] Not every brand manages to tick all boxes—sustainability is a work in progress, after all—but they should be transparent about it. At the very least, the best tea bags (UK, USA, wherever!) shouldn’t contain microplastics.