Is stearic acid a source of nickel contamination?

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Johnez

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On Reddit there's an opinionated person who's convinced himself that stearic acid in shave soaps is a "cheap" ingredient that artisans are using instead of using kokum or illipe. I explained the reason for using stearic acid isn't simply to cheap out while charging premium pricing, however he's also presented an argument that stearic acid is produced using nickel and that some nickel remains as a contaminant after it's produced. I've searched for how stearic acid is made and have not found any detailed process on how the stearic acid we use is made and am now slightly concerned. His source is a "chemist" he knows, however I've found another source stating the same-conveniently from the only shave soap maker that I've ever seen that does not use stearic acid:


Take a look at your top 5 soaps. Chances are the first ingredient on the list says one of these three things: Stearic Acid, Potassium Stearate, or Sodium Stearate. They are just 3 differrent ways to say stearic acid.

Stearic acid is very important to shaving soap to suspend a lather that does not break down. Other soapers typically use 50-70% of this cheap ingredient in their formula. The problem is, there is no such thing as a stearic acid nut, tree, or flower. So that means it is synthetically produced with chemicals; most commonly leached from Palm Oil by using a toxic nickel slurry as a catalyst. This can result in trace amounts of colloidal nickel in the finished product.

In addition to the annoyingly misleading "information" they also present this link as their source:

https://bit.ly/2UrAN5J (pdf file)

ETA- while I highly doubt that the stearic acid we use does* contain great amounts of nickel (I'm imagining immediate DOS...) it'd be nice to know what process is used in making the stearic acid we're using in soap.

*edited, meant "does" not "does not"
 
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Tell them back that nobody in their clear mind would open this link, as it is obviously contaminated with URANIUM. 😂

Seriously. Nickel is a common catalyst for hydrogenation, i. e. fat hardening. It is the reactive metal that attacks double bonds in unsaturated FAs to make them react with hydrogen to become saturated FAs. So, as with any conspiracy theory worth its money, there is a tad of truth in the allegations.
But for several reasons, it makes no economical sense to leave nickel in the final product. It is more economical to recover and reuse it – the whole point of a catalyst in the end, and then there are quite rigid legal regulations wrt trace metals. Finally, it's appealing for a hydrogenation company to sell to chemical, margarine, candle, soap … industry to have a product that doesn't disqualify itself by heavy metal contaminations.

Should there be nickel residues that are hard to remove by chemical means (the above PDF calls for phosphoric or citric acid washes), then they are tightly bound, and as such, don't have the same toxicological properties, until proven otherwise.

Those worrying about nickel intake, should first ban anything from alloyed/stainless steel (razor blades, cutlery, thermos flasks, interiors of dishwashers, kitchen sinks, etc.) from their life. Next all food that bears Ni (which is all, because nickel is an essential trace element (at least) for plants). Who knows, maybe evolution has even equipped our bodies with some tolerance against environmental pollutants?
Eventually, soap is wash-off, so it is a viable question why to start with badmouthing soap, instead of addressing the more intense exposure channels first?

Another outright classical fallacy is the equation of “there are processes to obtain SA via nickel-treatment of oils” with the generalisation of “(all) SA contains nickel”. The vast majority of (commercial) stearic acid is a byproduct of palm oil refinement (“triple pressed stearin”), and hadn't had contact with hydrogenation apparatuses, or Raney nickel at all.



tl;dr: Mediocre FUD. Were it 20 years ago, I'd say it's viral marketing commissioned by illipe/kokum marketers. But nowadays, it is a sorry fact that many of such pitiable busybodies are just happy with a bit of negative attention.
 

Johnez

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Well dang RO, that was a swift and thorough response, I really appreciate it. I think I'd end up looking like "Tim Taylor" from the show Home Improvement explaining the wisdom Wilson imparts to him if I go into detail, I'll do the best I can though. 🤣
 
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