Have we ever wondered what materials tea bags are made of and whether they are really completely compostable? The answer may be much less obvious than we expect. Tea bags may be wrapped in paper, which can be recycled, but at the same time they may contain unexpected plastics.
Once the tea leaves have been brewed, they can be disposed of in the dustbin or compost bin, or reused creatively if necessary.
The real difficulties arise when it comes to disposing of the tea bag itself. Tea bags appear to be made of fabric only, but many of them may contain plastics, as was shown in a survey conducted by the British magazine "Which? Gardening" in 2010.
This showed that most tea bags contain plastics, particularly polypropylene, a thermoplastic component often used in the production of tea bags.
How are tea bags manufactured and what materials are used?
Tea bags are usually manufactured using natural hemp fibre (Manila Hemp), to which thermoplastic fibres such as polypropylene are added, which are considered necessary in order to seal the tea bag. This makes the tea bags very strong.
The combination of the two materials results in the fabric we know, which is very strong and has a number of small holes to allow contact between the boiling water and the tea leaves, without the latter escaping from its envelope. The edges of the bags are then thermally sealed. With heat, the thermoplastic materials used melt, allowing the bags to be tightly sealed.
Doubts about the true compostability of tea bags arose among several readers of the magazine "Which? Gardening" who realised that, once the consumed tea bags were placed in household compost bins, they never seemed to disappear completely among the accumulated food waste. This was due to the presence of non-biodegradable thermoplastic materials inside.
When asked by the magazine, Teadirect manager Whitney Kakos confirmed that her company's tea bags are only 70% compostable and that the use of polypropylene is a widespread practice among tea companies. The suggestion of some British companies is to throw the tea bags in the compost anyway and to take them out at the time of use if parts of them are still visible. According to these tea companies, even though the tea bags contain thermoplastic materials, they should be considered as fully compostable and biodegradable.
So what could be the solution to avoid buying tea bags completely free of polypropylene? One could inquire with the manufacturers, hoping for their sincerity and asking them how the tea bags they sell are made. Some teabags, especially those with a paper label or staple closure with no other sealing, may be polypropylene-free.
In addition, many tea bag manufacturers use the biodegradable plant material instead of polypropylene, known as PLA.
Strictly necessary