Down to Earth Bamboo Toothbrushes are 100% earth friendly and made of extremely sturdy, biodegradable, and sustainable natural Moso bamboo, grown in Asia. Down to Earth Bamboo Toothbrush bristles are made of nylon and coated with superabsorbent porous bamboo charcoal. Bamboo charcoal is 4xs more absorbent than activated charcoal and has a high mineral content of potassium, calcium, iron, and sodium. Bamboo charcoal also has a negative ionic charge that attracts odors and toxins. Bamboo holds the world record for being the fastest growing and most renewable plant in the world, making it the perfect toothbrush choice when choosing to go green.