evidence: Believe it or not, the humble teabag often contains a non-biodegradable plastic called polypropylene, which releases billions of microplastic particles every time you brew a cuppa. [...] Biodegradability is not the only issue with plastic in teabags. If you’ve read up on environmental issues, you’ll have heard of microplastics, tiny fragments of plastic that pollute natural ecosystems. Research by McGill University found that a single plastic teabag can release 11.6 billion microplastic particles at brewing temperature. These take hundreds of years to break down and can cause a host of environmental problems. [...] Some high-end brands make the teabag itself out of plastic rather than paper. ‘Mesh’ is made from strands that are usually made of nylon or polyester and are woven to create a net-like fabric. Mesh teabags are often marketed as ‘silky’, but they are not made of silk. They release a huge number of microplastics and are not biodegradable.