An oxygen absorber is a small bag with a content that reacts with oxygen and consumes it. The absorbents come in vacuum-packed bags in an airtight bag. They are completely safe to use when storing food as they do not contain any toxic substances.
How oxygen absorbers work
Oxygen absorbers (also called oxygen eaters) consume oxygen chemically. The small cardboard-wrapped bags contain 80% iron filings and 20% activated carbon. As soon as a bag is exposed to air, the binding begins. The iron rusts and that process consumes oxygen. If this happens in a small, closed airtight environment, all oxygen will be consumed. This takes a couple of hours. If you feel the bag where the oxygen absorber is located, you will feel that it will be hot.
Why oxygen absorbers?
Oxygen is an ingredient in life, but is also destructive at the molecular level. Oxygen is the cause of rust formation, yellowing of newspapers and discoloration of silver. Oxygen also destroys food, either by oxidation or by oxygen-dependent organisms destroying the food. It manifests itself in unpleasant changes in taste, texture, appearance and nutritional value. These risks are avoided with oxygen absorbers in completely tight packages. In addition, the oxygen-free environment effectively kills all possible insects, larvae and eggs within a few days.
To counteract this, oxygen absorbers should be used when storing food in the long term.
Air consists of 21% oxygen. When you have closed a mylar bag with an oxygen absorbent in it, the air in the bag will be reduced by about 21%. The remaining gases (mainly nitrogen, 78%) are completely harmless for eg food stored in the bag. An oxygen-free mylar bag with food will not look like a vacuum-packed bag, but will shrink slightly depending on the amount of air in the bag and what you pack. If you squeeze as much air as you can out of a bag of peas or rice before you weld it again, it becomes vacuum-packed, while oatmeal rarely is, even if both bags are oxygen-free and the contents are protected.