Teabags: Which brands contain plastic?
The University of East Anglia has conducted tests on six of Britain's biggest tea brands in order to find out the amount of plastic included in their bags.
Each one of the teabags was placed in a copper ammonia solution for five days, which dissolved any material apart from plastic.
While the tests showed some bags degraded and broke down easily, others included significant amounts of non-biodegradable plastic.
Find out more: watch 'War on Plastic with Hugh and Anita' on BBC iPlayer.