An Oxygen absorber is a small sachet or packet of special material which is used to prolong the shelf life of food, drugs, electronic items and other products. They are used widely in the food industry to prevent food colour change, to stop oils from becoming rancid and also to prevent the growth of aerobic microorganisms such as fungi. Without oxygen, the growth of certain microorganisms is severely restricted. Plastic packaging is less able to exclude oxygen than other containers such as glass and cardboard packaging. Oxygen absorbers can absorb oxygen efficiently to reduce the aerobic environment to 0% oxygen, and this process can extend the shelf life of food products from one week to several months. Other options are available to food manufacturers such as vacuum packing, but the main disadvantage with this process is that the products inside tend to get squeezed which is unsuitable for certain items that are fragile and expensive.