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I'm aware that oxygen in the atmosphere of a sealed package can be readily removed by using oxygen absorber/scavenger such as granulated iron and sodium chloride but my understanding is that these bring the O2 content all the way down from 21% only limited by the permeability of the packaging to oxygen and the ratio of scavenger to package volume to something approaching 0%.

My question is if there is a way to formulate an oxygen scavenger that would be limited by some other processes to higher floor of say 5% to 10%... Without having to measure and calculate appropriate ratio of scavenger to package on a per use basis ?

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    $\begingroup$ So are you looking for a fully passive solution, not including active flows of gases? $\endgroup$ – Jon Custer May 4 at 17:31
  • $\begingroup$ Just to add, this is meant for semi permeable packaging such as paper or plastic where the ongoing reactions of the scavenger compensate for leakages. $\endgroup$ – norlesh May 4 at 17:33
  • $\begingroup$ Some of us might suggest that all packaging is semi permeable at some level. "Hermetic" seals are allowed to have a real, measurable leak rate... $\endgroup$ – Jon Custer May 4 at 17:36
  • $\begingroup$ Yes fully passive is my preference - failing that I will have to include electronics to activate some reaction via heat or otherwise periodically to maintain the atmosphere. $\endgroup$ – norlesh May 4 at 17:38
  • $\begingroup$ Was watching some YouTube on high vacuum set-ups for playing with plasmas just yesterday so I'm very cognizant of how permeable most packages would be :) $\endgroup$ – norlesh May 4 at 17:45
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Oxygen absorbers have the purpose to prevent food spoilage by oxidation (of fatty acids, flavors, etc.), so the desire is to remove oxygen as much as possible and also to bind small amounts which may diffuse into the package upon storage.

In order to achieve a certain defined oxygen containing atmosphere, consider flooding the package with an artificial gas mixture, e.g. 5% oxygen, 95% nitrogen. Should be easy to obtain from scuba dive shops who are filling bottles with homemade nitrox blends if they are willing to give you a custom mixture (which in this case is not suitable for diving).

Or just mix air and nitrogen or carbon dioxide (from a soda machine) by adjusting the flow.

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  • $\begingroup$ Thanks for your response but what I had in mind is more something that you could place in the package just like a traditional scavenger packet and it would actively regulate the internal atmosphere by one or more chemical processes $\endgroup$ – norlesh May 4 at 17:29
  • $\begingroup$ You'd need a reaction where free oxygen is in an equilibrium with bound oxygen and the status of the equilibrium is almost completely on the side of the oxygen. I think to find such a reaction is difficult to impossible. Of course, small bags to add would be a simple and convenient solution on the small scale. For production, the gas mixture might be cheaper on the long run, as there are packaging machines that can exactly do that for you, e.g. modified vacuum bag sealers which aren't really expensive. $\endgroup$ – imalipusram May 5 at 2:26

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