... from 100% biodegradable soft and medium bristle, nylon4, bamboo fiber, or corn fiber.2. We recommend you rinse and dry your toothbrush ... from 100% biodegradable soft and medium bristle, nylon4, bamboo fiber, or corn fiber.2. We recommend you rinse and dry your ... it to earth in compost or landfill. Both the bamboo and bristles will biodegrade into soil, without pollution. eco-friendly Bamboo Toothbrush