Resource Stability of SN and N

[GHome]

Did you get it from DMC? They ship it vacuum sealed, so that could be why it feels hard

Yes, it was from DMC. Thank you. So maybe it is good. I will not open it until "the day" come.

 

[U. A.]

I know @bed is hardly online these days and likely doesn't watch this thread (hence the tag, just in case), but after initially being calmed by this thread re: my vintage SN, I've noticed some significant issues. Would appreciate a response when possible, from OP or anyone knowledgeable:

The quote that follows and the citation for it refer strictly to medication, which SN isn't. It's a chemical. I don't know what the regulations are on chemicals, but in any event, this source only applies to legitimate-market pharmaceuticals, and only in the USA. Additionally, the conditions of whatever "lab" our questionable SN came from can't be verified to be at the level of commercial ones.

Again, apples and oranges—notice it says "If your curing salt is only salt and sodium nitrate or sodium nitrite". Not only do we know curing salt ≠ sodium nitrite, but this source is presumably about the expiration for the purposes of curing meat. In any event, curing salt is around 90% sodium chloride.

Where? The link that follows is to a topic page on SciendeDirect, not an article. There are many previews of many articles listed on that page.

What's the source on this? There is none whatsoever, not even a link to a post here or OP saying it was their own information. And to make matters worse there are five chemical indicator colors on that test strip. With no reference gradients, or even confirmation of which chemicals they even are.

I am absolutely not above bumping my own post in an effort to draw attention to it, so that it either might be more widely seen, or have its criticisms addressed.

 

[Caribbean Sky]

I am absolutely not above bumping my own post in an effort to draw attention to it, so that it either might be more widely seen, or have its criticism addressed

this is valid, but for a general person, can we just re-test every so often to ensure purity?

Mine's about 5-6 months old. I bought one batch to test and another that I wouldn't open until ctb. So it's still sealed and airtight. additinally, it's stored in a small, locked safe, inside of a cabinet.
so it's not temperature regulated, but throughout cold and hot months because of how it's stored it's temperature doesn't change as much and has remained relatively stable. Is that good storage ?

 

[rainwillneverstop]

I know @bed is hardly online these days and likely doesn't watch this thread (hence the tag, just in case), but after initially being calmed by this thread re: my vintage SN, I've noticed some significant issues. Would appreciate a response when possible, from OP or anyone knowledgeable:

The quote that follows and the citation for it refer strictly to medication, which SN isn't. It's a chemical. I don't know what the regulations are on chemicals, but in any event, this source only applies to legitimate-market pharmaceuticals, and only in the USA. Additionally, the conditions of whatever "lab" our questionable SN came from can't be verified to be at the level of commercial ones.

Again, apples and oranges—notice it says "If your curing salt is only salt and sodium nitrate or sodium nitrite". Not only do we know curing salt ≠ sodium nitrite, but this source is presumably about the expiration for the purposes of curing meat. In any event, curing salt is around 90% sodium chloride.

Where? The link that follows is to a topic page on SciendeDirect, not an article. There are many previews of many articles listed on that page.

What's the source on this? There is none whatsoever, not even a link to a post here or OP saying it was their own information. And to make matters worse there are five chemical indicator colors on that test strip. With no reference gradients, or even confirmation of which chemicals they even are.

The person providing the test and source wish to stay anonymous. But it has been verified.

 

[Whale_bones]

Again, apples and oranges—notice it says "If your curing salt is only salt and sodium nitrate or sodium nitrite". Not only do we know curing salt ≠ sodium nitrite, but this source is presumably about the expiration for the purposes of curing meat. In any event, curing salt is around 90% sodium chloride.

This is a good point. Two common types of curing salt, Prague Powder #1 and Prague Powder #2, each contain only 6.25% sodium nitrite, along with 93.75% and 89.75% sodium chloride respectively. Without having any chemistry knowledge myself, I would think this difference is so significant that we shouldn't be assuming what's true for curing salt is true for 98%+ purity SN.

What's the source on this? There is none whatsoever, not even a link to a post here or OP saying it was their own information. And to make matters worse there are five chemical indicator colors on that test strip. With no reference gradients, or even confirmation of which chemicals they even are.

It would be helpful to have the reference gradient for this test. Just working off assumptions, I would guess that this test strip is similar to others that have been posted (like here, here and here, with the two bottom pads measuring nitrate and nitrate) and that such a dark red color means the nitrite levels tested at the maximum reading possible.

However, different brands of test strips have very different maximum readings. I've seen some as low as 2.5 ppm, and others as high as 50 ppm. 25 ppm is a common maximum reading, but whether that's the maximum for these particular strips or not, there's no way to tell.

Bottom line IMO, no one should panic about their SN expiring, but they should always plan to test it with aquarium test strips shortly before it's needed.

 

[rainwillneverstop]

I am no chemist but have been looking into as much information as possible to try to give the most reliable info that I can. Forum members with aptitude for research and/or chemistry are also welcome to add to the combined knowledge of the forum to help with this aim.

Again, apples and oranges—notice it says "If your curing salt is only salt and sodium nitrate or sodium nitrite". Not only do we know curing salt ≠ sodium nitrite, but this source is presumably about the expiration for the purposes of curing meat. In any event, curing salt is around 90% sodium chloride.

From article that Bed linked: "Prague powder #1, Prague powder #2, tinted cure and pink salt are all curing salt. Prague powder #1 contains table salt and sodium nitrate; Prague powder #2, table salt and sodium nitrite as do tinted cure and pink salt. [..] Keeping these curing salts dry will keep them fresh and usable indefinitely."

The article defines curing salt as combinations of table salt and either sodium nitrite or nitrate.
Unless you are claiming that the table salt is preventing the nitrite and nitrate in that curing salt mix from degradation, then the original phrasing still describes high stability over an indefinite time if stored properly. While the statement is made in the context of meat curing, that context does not change the underlying chemistry, and it still supports that sodium nitrite does not undergo meaningful degradation and therefore has no practical expiration date when stored properly.

Where? The link that follows is to a topic page on SciendeDirect, not an article. There are many previews of many articles listed on that page.

It's possible that article or link has been removed/changed.

However - it seems as though there is not much information discussing ambient storage because the 'knowledge' is taken for granted across the industry that SN is stable, so research on degradation etc only takes place in extreme temperatures and conditions.

Data sheets like the one linked below do not have expiry dates, just that storage should be in a cool, dry place (Section 7) and that the shelf life is indefinite (Section 10). The absence of an expiry duration or warning of time-limited stability seems to inform the industry that expiry in ambient conditions is not considered an issue, with only hygroscopicity noted as a concern.

Sodium Nitrite SDS (Safety Data Sheet) | Flinn Scientific

Sodium Nitrite ► Flinn Scientific SDS Sheets ► Learn health and safety information about chemicals.

www.flinnsci.com

What's the source on this? There is none whatsoever, not even a link to a post here or OP saying it was their own information. And to make matters worse there are five chemical indicator colors on that test strip. With no reference gradients, or even confirmation of which chemicals they even are.

As addressed above earlier, the author of that photo wish to remain anonymous and I respect that but I have verified them.
However I did ask them if they could do another test, and this was the result:

 

[U. A.]

Thanks for the reply on this.

I am no chemist but have been looking into as much information as possible to try to give the most reliable info that I can. Forum members with aptitude for research and/or chemistry are also welcome to add to the combined knowledge of the forum to help with this aim.

I'll start with the disclaimer that I'm in the same boat regarding chemistry, but research is among my stronger suits. I have been looking into this independently and have also hit a wall finding anything definitive, which is what I would prefer when making decisions about whether or not I will die and think all members deserve as robust and well-sourced a body of information as possible on the matter. Hopefully someone with more expertise comes along sooner than later.

Unless you are claiming that the table salt is preventing the nitrite and nitrate in that curing salt mix from degradation, then the original phrasing still describes high stability over an indefinite time if stored properly. While the statement is made in the context of meat curing, that context does not change the underlying chemistry, and it still supports that sodium nitrite does not undergo meaningful degradation and therefore has no practical expiration date when stored properly.

What I was getting at there is that since the ingredient which is by far the primary constituent of Prague powder is something which does not expire, saying Prague powder by extension doesn't expire is a sound inference, but saying so about pure sodium nitrite is not.

We need to consider the amount when it comes to the purpose: for us, SN is to kill us. For curing, it's to preserve the color of meat, as noted by Tasting Table. Yes it also states it's to inhibit the growth of bacteria but salt alone accomplishes that. Cultures across time and place have known this and used it as such for hundreds or thousands of years. As noted in Vizzy's SN Bible (among other places), purity is extremely important and ought to be 95% minimum. Something tells me if the sodium nitrite in Prague powder were to degrade to a lower relative concentration of 5.8%, it would probably still do a fine job of color retention.

It's possible that article or link has been removed/changed.

Perhaps it can be changed or updated, ideally with an archived version of whatever page were to take its place.

it seems as though there is not much information discussing ambient storage because the 'knowledge' is taken for granted across the industry that SN is stable, so research on degradation etc only takes place in extreme temperatures and conditions.

Again, comparing our purposes—"the industry" is the chemical industry, where labs, sellers, and storage methods are reputable and quality-controlled, vs. guys possibly hanging out on the forum to peddle their home-cooked wares. Anyone who's not bought from an industrial/scientific source has absolutely no idea about the conditions of their product before it reached them, nor any way of finding out. The chemicals could well have been left exposed to open air for any period of time, ultimately shortening their shelf life.

Data sheets like the one linked below do not have expiry dates, just that storage should be in a cool, dry place (Section 7) and that the shelf life is indefinite (Section 10). The absence of an expiry duration or warning of time-limited stability seems to inform the industry that expiry in ambient conditions is not considered an issue, with only hygroscopicity noted as a concern.

Sodium Nitrite SDS (Safety Data Sheet) | Flinn Scientific

Sodium Nitrite ► Flinn Scientific SDS Sheets ► Learn health and safety information about chemicals.

www.flinnsci.com

This is helpful and good to see, though cf. my previous point re: pratfalls of equating reputable industrial sources with sketchbags like DMC who send "Happy New Years" texts to prospective clients he's eager to kill sell to.

As addressed above earlier, the author of that photo wish to remain anonymous and I respect that but I have verified them.
However I did ask them if they could do another test, and this was the result:
View attachment 192845

This is a much more informative photo and if it was provided directly to mods on request by a known source, that's about as good as we can get. As before, if the original post could be updated with this photo and the relevant context (including the age of this batch of SN, unless it's the same one), I think that would only serve to boost its credibility.