The natural charcoal odor absorbers are all you need. They effectively clean and purify the air, so you're always surrounded by a fresh, breathable environment. Begins absorbing odors & impurities the moment it's removed from the plastic shipping wrap. Each bag will last up to 2 years. To rejuvenate and re-activate the charcoal, place the bags in direct sunlight once a month for 1 hour. The bags are safe to use around pets & children. Charcoal air purifiers are made from environmentally friendly micro-porous activated bamboo charcoal.