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  • Sodium Lauryl Ether Sulfate @ 30% concentration.
  • (Quote) 
I wonder if Benzalkonium chloride is actually effective against the novel coronavirus. Read the study: Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agentsG. Kampf a, *, D. Todt b , S. Pfae…
  • Menthol is not water soluble. So you'd need either a semi-polar (co)solvent like alcohol, or an emulsifier.
  • Most chemicals in fragrances are nonionic, thus they shouldn't react with ionic surfactants. At the end, you should test them yourself. You can make a more concentrated solution to make any mild incompatibilities easier to spot. You can also "…
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Interesting. What's the manufacturer name for Ulcatrez? (Google ain't helping, it believes I'm looking for "Alcatraz", not Ulcatrez, LOL)
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If you're following the WHO guidelines, they clearly state that no thickener, or other ingredients must be added. You can make sanitizer gel if you want, but it won't follow the WHO guidelines.
  • What was the formula you tried? (with percentages)
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If it's for medical or hospital use, then yes, it needs to be sterile. There are some rare bacteria or spores that can survive, even inside 70% alcohol. (Quote) 
It will be a 1000 L batch. Sterile filtered with a 0.22 um fi…
    in Sanitiser Comment by Gunther May 15
  • These articles and studies suggest that a catalyst is needed for significant amounts of alcohol to by oxidized. Ferric ions:!divAbstract…
    in Sanitiser Comment by Gunther May 14
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That definitly works, thank you.  In fact we reduced the Carbopol content to make our last Carbopol Ultrez reserves last longer as it's very hard to find. It looks like a little Polyox might help reduce stickiness too. I'm still ex…
  • Aculyn 38 and 88 work but viscosity is a bit low. The 88 has a slightly higher viscosity, but they also leave a sticky after feel.
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Well, it look like overkill but specs call for a sterile sanitizer. (Mostly intended for medical/hospital use). Some rare bacteria and spores can actually survive in sanitizer fluid, hence the specs to make it sterile. Right now …
    in Sanitiser Comment by Gunther May 13
  • (Quote) 
May I ask what alcohol are you using? ethyl or isopropyl What's the alcohol concentration in the gel? I'm asking you because you can only make up to 60% alcohol using TEA (and that with Carbopol Ultrez, I don't know if that works w…
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We are actually considering making a sterile filtered WHO formula based sanitizer. I wonder what do we can do to sterilize the containers as they are not heat resistant thus not autoclaveable? In fact, a proposed formulation will b…
    in Sanitiser Comment by Gunther May 12
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I prefer cetyl as it has a more smooth feel. But cetearyl emulsions are reportedly more stable. You definitely need to buy small amounts of each one and try them both for yourself. Experimenting is key to succeeding in cosmetic che…
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IMO IPA smells worse than ethanol does, thus a great reason to avoid the former and choose the later. You don't need ethanol 99.9%. 94 / 95% ethanol will do. Pure ethanol is called 'absolute alcohol' is very expensive and readily a…
  • 8% Aculyn Excel yields a low viscosity gel (too low for my taste), but the real problem is that it leaves a sticky afterfeel.
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Interesting because you can clearly tell the difference between cetyl and cetearyl (I haven't tried Behenyl alcohol myself). I believe the cetyl/cetearyl difference is that the former is more homogeneous than the later, so the cryst…
  • 5% Aculyn Excel (as is), yields a very low viscosity gel for both 60 and 70% alcohol test batches. Just not thick enough for a sanitizer gel.
  • Add the water soluble, non foaming ingredients first, i.e. EDTA tetrasodium, preservatives, etc Predilute gel or thick liquid surfactants. i.e. predilute 70% SLES gel. Premix surfactants with fragrance (if the fragrance is not water soluble or if …
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At those low concentrations, Hydrogen Peroxide does NOT oxidize alcohol to an aldehyde or to a carboxylic acid. I was concerned about oxidation too, but after reading some chemistry papers it looks like it doesn't happen at such lo…
  • I have been rubbing my hands (and soak my facemask) with 3%  Hydrogen peroxide when returning home as a coronavirus prevention. It hasn't irritated my hands so far, but I quickly wash it off after drying, as it leaves a sticky afterfeel.
  • What happens with BZK? Does it precipitate out of solution?
  • IMO cetyl alcohol are less "draggy", but cetearyl alcohol emulsions are reportedly more stable.
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That's indeed the reason why. Na, K salts are very water soluble but not too alcohol soluble, hence the need to use "exotic" neutralizers. Salts are usually much less soluble in IPA than in ethanol.
  • You can read the study: Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents
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Well, according to some studies it ain't as effective
  • Oh yes, it's very effective against the coronavirus. Just don't drink it. It's not effective that way.
  • 5% might be too little for BTMS 25 (but ok for BTMS-50) double that to 8-10% Does BTMS-25 already contains a fatty alcohol?

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