One 2,000cc Oxygen Absorber is enough to remove all the oxygen in a 5 - 6 gal Mylar Bag. I like to use the 2,000cc absorbers so if I choose to open the Mylar Bag to retrieve my stored food and then reseal the bag quickly afterward, the 2,000cc absorber will continue to absorb oxygen.

Oxygen absorbers are made of a chemical compound, the active ingredient of which is a powdered iron oxide. These absorbers are completely safe. While they are not edible, they are not toxic. No harmful gases are created and the oxygen does not remove the fresh smell and taste of the product.