Bamboo is a renewable resource because it grows so quickly. The Moso bamboo plant used to make Ever Bamboo grows two feet or more in a single day.
These powerful charcoal packs remain effective for an entire year. And you can recharge them during that time, if needed. Put them out in the sun for a few hours to release any absorbed odors and moisture.
And adding to the environmentally-minded benefits, when the charcoal is finished fighting odor, put the pieces in your garden or potting soil. It will deter pests and absorb excessive moisture.