Made from bamboo, a natural cellulose fibre, they are 100% biodegradable, environmentally sustainable, and do not pollute the environment. The amazing growth and self-renewing ability of bamboo means that deforestation is not necessary either. The handle is made of bamboo, an environmentally sustainable timber. Bamboo is technically considered a member of the grass family. It is the fastest growing plant on earth, and incredibly abundant. The bamboo is heat treated to carbonise the surface of the bamboo, giving it a quality finish and good service life. The carbonisation finishing process provides water resistance and prevents the growth of microbes (bacteria and moulds) during normal use. The bristles are made from a polymer resistant to microbial growth during normal use, to ensure safety and durability. We recommend you rinse and dry your toothbrush after use to keep it clean.