All of our tea bags are biodegradable. The materials used for the tea bags, string and tags are PLA woven mesh, with PLA thread and a paperboard tag with PLA coating. PLA (polylactic acid) is a polymer resin made by the lactic fermentation of glucose which is derived from corn starch.   If your local authority does composting on an industrial level they can also be thrown into your household compost bin. We highly recommend checking the rules on your local authorities food composting bins.