Resource--Oxygen Absorbers

How are they used? To lower the oxygen content in containers of dry packaged foods. For successful long-term storage, commodities stored must be shelf stable and low in moisture and oil content.*  To protect the stored food from insect infestation and help preserve product quality.

What are they made of? Elemental iron mixed with a moisture absorbing material.  Packet covers are made of a semi-permeable material that allows oxygen and moisture to enter, but does not allow the contents of the packets to leak out. 

How do they work? When moisture is absorbed into the packets, it causes the iron to rust. The process
of oxidizing the iron absorbs the oxygen from the package atmosphere.

Temperature and the moisture level in the container determine the rate of the reaction.

Mitsubishi Ageless ZPT 300E absorbers are rated for 300cc of oxygen each. With their reserve capacity,
each absorber has adequate capacity for up to 1 gallon (4 liters) of properly packaged food.

Is this the same as vacuum packaging? Not quite, the absorbers remove only the oxygen. 

Air is about 20% oxygen and 80% nitrogen. The residual air [volume] in the container is mostly nitrogen,
which will not affect the food. 

What types of containers can be used with oxygen absorbers for food storage? Containers that
provide an effective barrier against moisture and oxygen. 

Examples include:

• Foil (Mylar) Pouches (such as those provided by Church home storage centers)
• Metal # 10 cans with seamed lids
• PETE plastic bottles with screw on lids. 
• Glass canning jars with gaskets in metal lids
• Buckets--Oxygen absorbers are not an effective treatment method for plastic buckets, milk bottles or other types of plastic containers not identified as PETE or PET under the recycle emblem.

Directions for using Oxygen Absorbers:

Cut open the top of the bag of absorbers. Do not cut open the individual absorber packets.

Remove the number of absorbers from the bag that you will use in the next 20 to 30 minutes and spread them out on a tray. Do not repeatedly open and reclose the bag for a few absorbers at a time.

Reseal the remaining supply of absorbers by one of the following methods:

• Seal the absorber bag temporarily with the special blue clamp provided by the home storage center.
• Seal the bag of absorbers with an impulse heat sealer.  Do not store absorbers in zip lock bags.   
• For longer storage, if an impulse sealer is not available, remove the absorbers from the bag and place the absorbers into a glass canning jar with a gaskets in the metal lid. One pint (500 ml) will hold approximately 25 absorbers.

Place one absorber into each container of food as it is packaged. Remove additional groups of absorbers from the supply, as needed, during packaging.

*Caution: Products that are too high in moisture should not be stored in oxygen-free containers because they may produce lethal botulism toxin.

Source: Bishops’ Storehouse Services