Oxygen absorbers are used to protect packaged foods and other products against spoilage, mold growth, color change, loss of nutritive values, insect damage and loss of quality. By removing residual oxygen inside packaging to below 0.01% this 300 CC oxygen absorber effectively preserves packaged foods without the need for food additives or preservatives and without the need for vacuum sealing. For use in gallon-size Mylar bags.