Squalane and Squalene

I got into a bit of trouble talking to a young woman in an internet chat room the other day.

Actually its not as bad as that makes it sound. She was a very earnest person who had been thoroughly researching her personal care purchases and had lots of points and opinions. Unwisely, I decided to correct one minor error I thought I had spotted.

She had said that cosmetic companies had not been able to tell her that they categorically did not use squalane derived from sharks livers. This took my mind back to my first job in formulation back in the early Eighties. I had been shown a tiny bottle of squalane. This was, I was told, a very rare thing – actual shark squalane. You couldn’t get it any more since the EU had banned its import or sale.

I was very glad about that. I didn’t like the idea of sharks being killed for purely cosmetic reasons. I am a chemist not a moral philosopher and I can’t think of any good reason why using shark derivatives in a skin cream is any worse than tucking into cod and chips. I have a feeling if I thought about it I would have to give up the cod too. Lets not go there, eh!

But anyway ever since then every time I have come across a sample of squalane it has always been vegetable derived. No sales rep has ever offered me the shark stuff. As far as I was concerned it was ancient history. So I cheerfully weighed in and assured the concerned young woman that nobody had used shark derived squalane for decades and there was no reason to deprive herself of a very good skin care agent. You couldn’t get hold of the shark stuff if you wanted to, I said. And even if you could any company would be mad to use it given bad publicity they might get.
I thought I was doing her a favour, though at my age I should know that the last thing most people want to hear is that they have got something wrong. In fact, I was about to have first hand experience of exactly that myself. When I checked none of the big suppliers were offering shark derived squalane, but there was one small and rather obscure one that was. What I had said was still technically correct. At the time of writing I hadn’t known where to get shark squalane. And it was obvious that the bulk of the squalane in use was indeed vegetable derived.

But as every politician and salesman knows, a fact can be both true and misleading at the same time. I hold myself to higher standards than that. So I thought I had better correct what I had said, which I did. In the meantime she had posted links showing that Unilever had only recently stopped using shark squalane. And when I say recent – last year. (The article also said that other companies had long standing policies of not using shark squalane.)

I double checked trying to find some kind of wriggle room, but the links checked out and were corroborated by other reputable websites. So I had to apologise again. She was not impressed at all and announced that she regarded herself as better informed than me. Oh well. At least I learned something.

So here is the current situation. Squalane from sharks is not used in cosmetic production any more. I don’t think much has been used for a long time but it turns out that a few companies may have been using some as recently as last year.
But it does give me a chance to write about an interesting material, in fact a couple of materials. For a start, it is not squalane but squalene that is found in nature. Squalene is an oil that is found in most living things. I don’t know why sharks are a particularly rich source of it. I could hazard a guess that at least one thing they use it for is to maintain a good skin barrier which they will need living in salty water. Olive plants are another good source and obviously the one that most of choose. Squalene oxidises slowly to squalane once it is removed from its source.. Squalane is the preferred form for adding to cosmetics because being already fully oxidised it is unlikely to react with anything else in the formulation. But you do see formulations with squalene so it must be stable enough to use if you put your mind to it.

Squalane is produced from squalene by a process called hydrogenation. Hydrogenation is generally a process that alters natural materials in a way that alters their shape and on the whole I think it usually makes materials less beneficial. But I do appreciate that it does increase shelf life. Squalene is an expensive material to produce and is used in small quantities. I can see the temptation to use the hydrogenated version that is going to last longer. In terms of skin feel I personally can’t tell the difference between squalene and squalane. But squalene is the form you actually find in the skin so that is the form that is probably going to be more easily incorporated into the skin and do more good when it gets there.

Squalene is 10-14% of the oil in sebum according to some estimates. It seems likely to me at any rate that it forms a sort of filler in the intricate structure close to the surface of the skin that gives the skin its barrier properties. I find it easy to imagine that if you applied it to dry skin it would be moisturising, possibly quite strongly. Unfortunately I haven’t been able to find any evidence to back up this idea. For some reason, the other components of the skin’s oily layer have attracted much more attention. I think this may be because squalene is a pretty dull molecule from a chemist’s point of view. It is basically a long thin dollop of fat without an interesting shape and without any reactive sites. But this may be a mistake. Sometimes it is the quiet ones you have to watch.

 

 

References

This is an up to date quantification of skin oil components.  (Lipid means the same as oil in this context)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2835894/?tool=pubmed

This 1986 review of the role of oils in the skin makes almost no reference to the part played by squalene, and I haven’t found anything later that expands on it.

http://onlinelibrary.wiley.com/doi/10.1111/j.1467-2494.1986.tb00439.x/abstract