Goodfloss and Premium toothbrush refill heads are made of polylactic acid (PLA), which is a plastic substitute made from a base of fermented plant starch. It is compostable in anaerobic environments, meaning a controlled industrial composting facility, which may not be available in your area. We’re trying to stay at the forefront of material technology, and PLA is the best alternative to petroleum-based plastics that both performs with the necessary strength and is available to us on the market for raw materials. We’re testing experimental materials like PHA, which is degradable in marine environments (awesome!), but it doesn’t work very well for the flosser or brush head because it’s too flexible in the existing formulation. If you run a company working on next-generation bioplastics, please get in touch with us!