The Coop is testing a “fully biodegradable paper tea bag”, a move that could save nine tonnes of plastic finding its way into composting and anaerobic digestion plants.
Some tea comes in compostable bags, but the majority of the mass-produced brands use paper ones that also contain around 25% polypropylene; this allows them to heat seal the bag.
The Coop said their new bag could be available later this year and will be “fully compostable in food waste collections after use”.
Regular, plastic-infused bags can also be put in composting or food waste bins. However, the resulting compost or digestate (from the process of anaerobic digestion) will inevitably contain tiny fragments of plastic.
Whether this is a problem when it is spread to land or not is a moot point. According to a report by Resource recently, experts confirmed that the fibres won’t result in AD outputs failing quality standards.
However, little is known about the impact of microplastics on soils, or whether there are potential issues with contamination of the food chain further down the line.