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Need some help with surfactants
I’m not a chemist (did one chemistry paper at uni), and I need some clarification on surfactants.
The term ‘natural’ is such a loose definition, that nearly everything can be considered natural in one way or another.
But I’m struggling with the so-called ‘naturally derived’ definition.
In my opinion, just because one component of an ingredient is natural, but if other non-natural ingredients are required to make an ingredient, then it can’t really be considered naturally derived.
Here’s what I understand so far:
Sodium lauryl sulfate (SLS) is made from lauric fatty acids which can be either petroleum or vegetable oil derived. Sodium coco sulfate (SCS) is made from a blend of different fatty acids, including lauric, oleic, stearic, linoleic, etc. and they use the term ‘coco’ as a easy way to designate that several kinds of fatty acids are used, and I’m guessing coco because it’s derived from coconut. Both SLS and SCS are made by reacting the fatty acids with chlorosulfuric acid and then neutralised through addition of sodium bicarbonate or sodium hydroxide.
Question 1: Is chlorosulfuric acid considered natural? I’m guessing not.
SLS can be further ethoxylated to produce sodium laureth sulfate.
Question 2: What is ethoxylation and what is used?
Then there are Sodium Lauryl Sulfoacetate (SLSA) and Disodium Laureth Sulfosuccinate (DLS).
Question 3: How are these produced?
And lastly, sodium cocoyl isethionate is produced by ethoxylation of sodium sulphites.
Question 4: Are sodium sulphites natural?
I also have some other questions:
Question 5: What is behenyl dimethylamine?
Question 6: What is Distearoylethyl Hydroxyethylmonium Methosulfate?
I’d be so grateful for any help.
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5 Replies
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Good questions.
Naturally derived is no different than natural in terms of a definition. Anything can be considered naturally derived.
1. That depends on how you define natural. It’s not supernatural so…it’s natural. It’s not petroleum derived…so natural. It’s as natural as Zinc Oxide. But it’s not generally found in nature so by that measure it isn’t.
2. SLS is not ethoxylated. Ethoxylation is a reaction with ethylene oxide. Sodium Laureth Sulfate (a different molecule) is ethoxylated. SLS is not.
3. Google search. Start with this patent. https://patents.google.com/patent/US5616782A/en
4. See answer 1.
5. Don’t know. Maybe you have the wrong name. Probably a conditioning ingredient.
6. Conditioning agent / emulsifier.
Your comments about SLS and SCS are not quite right. SLS is either made from petroleum or coconut oil. Coconut oil is around 50% lauric acid so companies that want to produce SLS would just distill the coconut oil further to isolate a higher percentage of lauric acid. However, it is too difficult to get pure lauric acid to create SLS so you never get 100% pure SLS. There’s always some C10, C14, C16 blended in. This is true even when you use petroleum as the starting material. This is also true of SCS which is made from coconut oil. It’s just that they don’t go the extra step of isolating fatty acids.
Calling ingredients “natural” is mostly marketing fluff.
Cosmetics are not natural. -
Thanks, Perry! That’s been really helpful. And thank you for clearing up the difference between SLS and SCS.
2. Sodium laureth sulfate is ethoxylated, you say. Is that SLS that has gone through the extra step of ethoxylation with ethylene oxide to become sodium laureth sulfate?
6. I got as far as it being a conditioning agent. But got stuck on the ‘Hydroxyethylmonium’. Something with hydrogen, oxygen, ethyl and ammonium, I’m guessing. But what is it? Some kind of special ethylene oxide?
(Geologist here, so chemistry really very basic)
That whole ‘natural’ thing is really annoying. And everyone defines it by their own rules. Imo, everything is naturally derived at some point. And even petroleum could be considered natural, since it occurs naturally. But I’m guessing what people are asking is if something is organic (as opposed to inorganic). But then they also define clays and micas as natural. Go figure.
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Things that this crowd calls ‘not natural’ in the majority of cases have much better performance.
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@kiwigirl71 - the frustration over natural is why a few organizations developed natural standards. In the EU the biggest natural standard is COSMOS. In the US, the NSF or NPA. You can read about them here.
https://chemistscorner.com/cosmetic-chemists-guide-to-natural-and-organic-cosmetic-standards/What you find is that all of these organizations loosen the rules over time to allow for more synthetic things to be considered “natural” because formulators aren’t actually able to make good products under sever restrictions.
2. Well, not exactly. The ethoxylation happens before being turned into a sulfate. So, lauryl alcohol is ethoxylated then that is reacted to form SLES.
6. You can see molecular structure here. http://www.saapedia.org/en/saa/?type=detail&id=7838 And the IUPAC name: Ethanaminium, 2-hydroxxy-N-methyl-N,N-bis(2-(1-oxooctadecyl)oxyethyl)-, methyl sulfate
Cosmetic Chemists Guide to Natural and Organic Cosmetic Standards
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Thank you, Perry!
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