How to Use Oxygen Absorbers When Stockpiling Food

While oxygen absorbers are relatively simple to use, there is a lot of misinformation and confusion out there. If you use the absorbers incorrectly, your food will be ruined when you need it the most. This can be fatal to you and your family in a long term disaster and must be avoided at all costs.

To ensure this doesn’t happen to you in an SHTF situation, we’re going to learn how to use oxygen absorbers properly to store your food safely for the long term. With careful attention to details, you should have plenty of food well preserved and delicious if or when the power grid goes down.

What Are Oxygen Absorbers?

Oxygen absorbers are little packets of salt and iron powder that decrease the level of oxygen within a container or package. They have been used by preppers as an inexpensive and harmless method to preserve their food storages since the early 1990s.

The primary goal of using oxygen absorbers is to reduce residual oxygen levels inside cans or containers to military specifications of less than 2%, thus preserving the shelf life of the food inside.

Why Use Them?

The two primary reasons you will want to use oxygen absorbers will be to prevent oxidation and to inhibit the growth of mold and bacteria. Both of these things increase the shelf life of the majority of foods dramatically. Oxidation is what causes the deterioration of the color, taste, flavor, nutrition, and texture of foods.

Some foods are more vulnerable to oxidation than others, but as we’ll see later in this article, even these foods can be stored long term with oxygen absorbers if you use the right type of container. Oxygen absorbers are also non-toxic and very safe to use. The packet can be discarded through ordinary means and does not require any kind of special method.


Live organisms of any kind cannot live in oxygen free environment, including microorganisms.

The lack of oxygen immediately eradicates the chance that any live organisms can survive and would be a barrier against adult insects laying their eggs there.

There are many additional reasons to use oxygen absorbers to store your shelf food:

  • It improves the qualities of polyunsaturated oils and fats
  • Eliminates the necessity for additives like sulfur dioxide
  • Retains the flavor of nuts and coffee
  • Stops oxidation of Vitamins A, C, and E
  • Absorbs all oxygen that permeates vacuum packaging
  • Reduces condensation and oxidation of red pigment on sauces and berries
  • Reduces mold on fermented dairy products such as natural cheeses
  • Increases the life of most pharmaceuticals
  • Inhibits the growth of pathogens

Examples of products that you can preserve with oxygen absorbers include:

  • Pastries
  • Cookies
  • Grain Items
  • Nuts
  • Coffee and Tea
  • Whole fat dry foods
  • Cured meats
  • Spices and seasonings
  • Dairy products
  • Dried fruits and vegetables
  • Flour
  • Precooked pasta and noodles
  • Vitamins
  • Birdseed
  • Pet food
  • Pharmaceuticals
  • Book and Art Preservation
  • Medical Diagnostic Kits

The food that you do store with your oxygen absorbers will need to be dehydrated, meaning oil and moisture content reduced less than ten percent. Otherwise, eating the food can result in botulism poisoning, a potentially fatal paralytic illness. Certain foods such as brown rice or granola bars have a shorter shelf life of 6-12 months because of their oil content.

What Size of Oxygen Absorber Do You Need?

The size of oxygen absorber that you need is largely dependent on both the size of your selected container and the void area within the container (or the area within the closed container not taken up by food). Oxygen absorber packets come in sizes from 20 to 2000. These sizes reflect the numbers corresponding to the amount of oxygen that can be absorbed by the packet in milliliters.

To decide what size of oxygen absorber you need, calculate the size of the void in the container. Then calculate the equivalent air volume, knowing that oxygen makes up about 1/5 of the normal air volume. Divide the equivalent air volume by five and you will get the absorption capacity of each packet. Using this formula, an oxygen absorber packet with a size of 100 would therefore absorb 100 ml of oxygen that is contained inside 500 ml of air volume.

Choosing a Packaging Material

Your packing container must be a food grade container. This means it will not transfer any chemicals, or at least not those harmful to human health, into your food. This automatically disqualifies many plastic buckets and bins available on the market. Oxygen absorbers work well in bottles, buckets, cans, and films that have strong airtight characteristics.

Avoid any carrying devices that have inadequate seams or that can’t sustain heavy damage from rough handling. Pouches, for example, are not airtight and are not as well protected as a closed can or bucket. A pouch won’t work if you’re primary preservation method is oxygen absorbers.

Plastic buckets:

  • Use only if marked “food grade”.
  • Are generally thick and will preserve food 2 to 5 years with oxygen absorbers.
  • Oxygen will very slowly be transferred through the plastic (polyethylene) bucket.

Glass jars:

  • Will not all oxygen to seep in over time through the sides like plastic.
  • Tend to be smaller and will not hold as much food.
  • Lack the durability of plastic, can crack and allow oxygen inside.

Inspect any container for any holes, cracks, or leakage points prior to using. If there are any, the oxygen absorbers will fail and your food will go to waste. Specifically inspect seams of plastic buckets and jars to ensure they are tight and won’t allow outside moisture or oxygen to seep inside and ruin your food.

The tightest seal must be between the bottle and the closure; consider using an additional material to wrap around here that you will only open when you need to access the food.

Using the Oxygen Absorber

Using an oxygen absorber is easy once you get the hang of it. Oxygen absorbers are a safe and economical option to keep your food protected and oxygen free. They will keep your food safe long term as long as you follow each step in order.

  1. Choose the proper packaging container/material.
  2. Place the appropriate size oxygen absorber inside.
  3. Seal the lid as tightly as you can over the container.
  4. Store in a cool place away from sunlight and moisture.

It can take as long as four days for the inside of the container to become an oxygen free environment. Oxygen absorbers also have a short life span once taken out of their original packaging. Most oxygen absorbers last only four hours or less before going bad after being exposed to air.

Experts recommend you have all your containers filled and ready to seal before opening the original packing on your oxygen absorbers. Place them inside your container and seal immediately. In addition, the longer oxygen absorbers are stored in their original packaging the less effective they become.

Use purchased oxygen absorbers in less than six months, and the sooner the better for maximum effectiveness. Leftover oxygen absorbers should be quickly resealed in their original packaging, Ziploc bags are not as airtight, or should be discarded if exposed to air for four hours or longer. Store in a cool, dark location where temperature is less than 85 degrees Fahrenheit (preferably less than 70F).


Let’s answer some basic questions that you might have about using oxygen absorbers for prepping.

Can They be used at Low Temperatures?

The short answer is generally no because the lower the temperature, the slower the oxygen absorption rate will be and this means that the shelf life of your food will not be as long as it could be in moderate temperatures.

At the same time, the activity of any microorganisms will also be dramatically less in lower temperatures, so it’s not a huge risk. Nonetheless it’s always better to be safe than sorry and store your food containers with oxygen absorbers in them in a dimly lit location at a moderate temperature. This is especially true for a survival situation where you can’t afford anything bad happening to your food.

Why Can the Master Bag of Oxygen Absorbers Feel Hot at Times?

First of all, this is nothing to be alarmed about. When the master bag that contains a type of absorber that is self-reacting is opened up, and as the packets are taken from the bag one at a time, then heat can generate from the oxygen absorber reactions and gather inside the bag.

While this can negatively affect the quality of your oxygen absorbers you can solve problem by spreading out the packets apart from one another.

Does Repeatedly Opening, Closing, and Re-Opening the Master Bag Affect the Quality of the Oxygen Absorbers?

This is an important question for those who only use small quantities of the oxygen absorbers at a time. Remember that the absorbers will only last a maximum of four hours out in the open before they’ll need to be resealed in the bag, placed in an airtight container, or discarded.

It’s not a good idea to repeatedly open and close your master bag as the packets inside then repeatedly come into contact with the outside oxygen. If you are planning to purchase a large quantity of oxygen absorbers but will only use a few at a time, experts recommend buying several smaller bags of packets rather than one large bag of packets.

Is It Safe to Use Oxygen Absorbers with Vacuum Packages?

Defining our terms, vacuum packaging is a type of packaging that removes air from the package before it is sealed. The amount of air will obviously already be lower in a vacuum package, meaning that you would have to choose a smaller absorber.

In the scenario where there is a strong vacuum ratio, you would need to put the oxygen absorber packet with distance between the food and the packaging material. Therefore, it is safe to use an oxygen absorber in a vacuum package since a vacuum package cannot eliminate all of the inside oxygen like the absorber packet can.


Food storage needs to be one of your top priorities to prepare for a long term disaster. But improper storage can make good food deadly. Oxygen absorbers are a superb way to keep your stored food fresh. With careful adherence to safety procedures, you’ll be able to keep yourself and your family fed and strong for when disaster hits.

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