10016221BioBristles: Reducing plastics waste through development of biodegradable toothbrush bristlesClosedCollaborative R&DInnovate UKToothbrushes have been used to improve oral hygiene for centuries. Toothbrush bristles originally relied on animal hair, ranging from inexpensive boar to premium badger hair. However, natural bristles are porous and absorb water, leading to bacterial growth. With the invention of nylon in the 1930s, natural bristles were replaced with synthetic nylon, which is more hygienic and thought to be more effective at removing plaque because of the higher bristle stiffness. However, plastic toothbrushes are generally made from a mixture of up to 4 different types of plastics, which cannot be easily separated for recycling. It is estimated that each year, we use and throw away over 3.6 billion plastic toothbrushes worldwide, producing 60,000+ tonnes plastic waste, of which around 80% reaches the oceans, where the plastic breaks down slowly to release microplastics, which enter the food chain through ingestion by fish. The impacts of microplastics on the environment and human health are not yet well understood; however, since microplastics are known to persist and bioaccumulate, it is recognised that there is no safe threshold for their release. To address the plastics crisis, certain single-use plastics (including disposable polystyrene cups/lids, cutlery, plates, and straws) have been banned in the UK and the EU. However, the ban is restricted to items for which readily available alternatives already exist and does not extend to plastic oral care products such as toothbrushes or dental floss. Even amongst the plethora of new eco toothbrushes (typically based on bamboo handles) the bristles are still manufactured from nylon. At end-of-life, consumers are often instructed to remove the bristles by soaking the toothbrush head in boiling water and then plucking out the bristles with pliers. The biodegradable bamboo handle can then be disposed of in household food waste, while the bristles must be collected and returned to the manufacturer for recycling. The key challenge of developing biodegradable toothbrush bristles is to deliver a product that matches or exceeds the mechanical performance, efficacy, and hygiene properties of nylon bristles in use, while biodegrading at end of life (ideally even under home-composting conditions). With funding from Innovate UK, London-based start-up Tooth.eco will develop the world's first plastic-free toothbrush, with biodegradable bristles that can match the performance of nylon bristles and safely break down under either industrial- or home-composting conditions. This project will demonstrate UK leadership in sustainable oral care and consumer product design, while supporting UK Plastics reduction targets.