BPA-free bristles from Castor oil, an ergonomic compostable Bamboo handle, in zero-waste & plastic-free packaging. This brush has medium BPA-free bionylon bristles made from Castor oil and a handle made from fast-growing, panda-tasty Bamboo. It comes in Soft, Medium, Firm & Kid's Bristles. BPA-free bristles from Castor oil, an ergonomic compostable Bamboo handle, in zero-waste & plastic-free packaging. This brush has medium BPA-free bionylon bristles made from Castor oil and a handle made from fast-growing, panda-tasty Bamboo. It comes in Soft, Medium, Firm & Kid's Bristles.