Some "biodegradable" teabags don't properly decompose, Bath study finds
There's calls for more accurate information on product labels
Some teabags containing plastic alternatives are not biodegradable and are potentially harmful to invertebrate species, a study from the University of Bath has shown.
The research found that teabags, containing the plastic alternative known as polylactic acid (PLA), remained either completely intact or only partially decomposed – apart from this material.
The study’s lead author, Dr Winnie Courtene-Jones, said: “In response to the plastic waste crisis, biodegradable plastics such as PLA are being used in an increasing range of products."
Polylactic acid is derived from corn starch or sugar cane.
The study also found that earthworms were harmed by these teabags, where exposure to different concentrations of tea bag discs resulted in up to 15% more deaths.
The research was conducted as part of BIO-PLASTIC-RISK, observing the decomposition of common teabag brands across seven months.
This comes after previous research suggested that some products labelled as biodegradable, do not disintegrate until as much as three years post-disposal.
The leader of the BIO-PLASTIC RISK project, Professor Richard Thompson, said: “It is with immense frustration that I see alternative and substitute materials entering the market without clear guidance on how their benefits might be realised.”
Only one brand of teabag manufacturer chosen for the study indicated that the teabags were not suitable for composting.
The study’s authors urge for more accurate disposal information to be disclosed on product packaging.