Those who store food at home often face a problem: they buy a package with dozens of oxygen absorbers, use some in a grain jar, and save the rest for later use. Weeks later, when reusing the leftovers, the food does not last as expected, even though it seems like the absorber worked.
The problem is not with the product itself, but rather with time. The oxygen absorber is activated by a chemical reaction that begins as soon as it comes into contact with air, not only when it is effectively used for food storage.
The food oxygen absorber is made with iron powder, activated by salt (sodium chloride) and neutralized by activated charcoal. Inside the original packaging, sealed under vacuum, there is no oxygen available, which keeps the iron inert and preserved for an indefinite period.
Essentially, it is the same reaction that forms rust on any metal piece exposed to air. Once the package is opened, the iron oxidation process begins immediately, and the absorbers progressively lose their effectiveness until they become completely inefficient.
