We have received many questions regarding oxygen absorbers. “What are they and how do they work?”, “How long do I have to use them after opening?”, “How do I know they are working?”, “How many do I need to use?”, “Are they safe?” are just a few examples.

We understand you want to be fully confident about the food you are preserving and trust us, no one wants to open a container or bag to find spoiled, moldy, or even bug-infested food. Yuck!

So, what are oxygen absorbers and how do they work? Oxygen absorbers (also known as Oxygen Absorbing Packets, oxygen scavengers, or oxygen eaters) contain an iron powder formulation that becomes iron oxide in the presence of oxygen, chemically trapping available oxygen from the surrounding environment. They should not be confused with desiccants, which absorb moisture, not oxygen. An oxygen absorbers is like a sponge that will continue to absorb oxygen until full and needs to be kept sealed prior to use to unsure it will absorb its full capacity.

This leads us to the next question; how long do you have to use them after opening them? It takes about 2 hours for an absorber to become full and at that point they will not absorb anymore. We recommend you either use them or store them within 10 minutes of opening them, but realistically you do have a little more time, just don’t let them become exposed longer than necessary. One of our favorite methods of storing unused oxygen absorbers is a mason jar. Just drop them in and seal the lid tightly. They will absorb the oxygen in the jar and then remain indefinitely able to absorb in the future. Mason jars have that button on the top and because a jar is not flexible like the bag is, the button will always be sucked in when the oxygen is removed, this is a good way to reassure the oxygen is being removed and the absorbers are doing their job. You may also vacuum seal the remaining absorbers if you have a Food Saver or another vacuum sealing machine. We recommend purchasing our oxygen absorbers in Compartment Packsto reduce exposure, waste, and resealing time.

Now that you know HOW they work, you may be wondering if they're even working...
and the answer is most likely yes, they are working. OAPs are a very simple technology and there is nothing to "fail" or not work. They contain iron powder and that iron becomes iron oxide in the presence of oxygen; in other words, it rusts! Iron will always rust and the only reason it will not is if it has already completely rusted by being exposed to the air. You can feel the rust inside an exposed OAP. It feels hard and crunchy instead of soft and powdery. If it feels soft and powdery, and the bags have been properly sealed, it will always work and you can feel confident. One of the biggest questions regarding this topic is,  “The oxygen absorbers feel hard. Are they bad?” If you have not yet opened the oxygen absorber package, then they will feel very hard in the package because they are vacuum-sealed. They are filled with an iron powder that is all smashed together under vacuum. We have never seen a factory sealed package with exposed OAPs in it unless the package was damaged. The OAPs in our sets are all factory sealed, but we do make our compartment packs here and we go through 1000s a day so you can feel secure about their reliability, especially if you feel it first. Also, before opening any vacuumed sealed oxygen absorber, make sure the oxygen indicator is a shade of pink or red, not dark blue - the indicator will turn dark blue when oxygen is present. We will get more into the topic of oxygen indicators in a later post.

What size oxygen absorber do you need? There is a variety of different sizes of absorbers and sometimes it is hard to determine how much is needed for the container you plan on using. If you like to keep things simple, you can buy a Mylar / Oxygen Absorber Set and not have to worry about food types and cc's. The Oxygen Absorbers PackFreshUSA includes with our sets are enough for any food type and any situation.

Our sets have been created so that any food type can be put into one of our Mylar bags and the Oxygen Absorber we send with it will be large enough to deoxygenate the bag when it has been filled with food.

200cc worth of oxygen absorbers are enough for a quart container, but as our quart bags can hold more than a quart, we use 300ccs in our Mylar sets.

Not only is it okay to use more absorbing power than necessary, it is a great idea. For one reason, food types can be deceiving and may contain far more air than you thought. Flour can be 50% air! Pastas can be 75% air! A larger capacity Oxygen Absorber will help account for this. Also, even if there was a tiny leak in the seal, a larger absorber will continue to absorb incoming oxygen, even many years later.

Now that you know all this great and useful information, you may be wondering if they are safe. PackFreshUSA Oxygen Absorbers are rated by the FDA as "GRAS". (Generally Recognized As Safe) They are safe for direct food contact and all of the materials used in their manufacture are non-toxic. However, for obvious reasons, please do NOT eat them.