Wednesday, August 11, 2010

Esters: C12-15 alkyl benzoate

C12-15 alkyl benzoate is an ester you'll see a lot in commercial products as it is an emollient, skin feel modifier (makes other oils feel less greasy), an anti-tackiness agent, lubricant, and binder and wetting agent for mineral make-up products. It also works as a solvent for sunscreen ingredients, making it easier to incorporate those ingredients into a day-use moisturizer. It has an HLB of 13 and the suggested usage is 1% to 15%. It's a clear, oil soluble ester that is stable in products with pH ranges of 2 to 12 - in other words, pretty much every product we make.

Like other esters, C12-15 alkyl benzoate will reduce the feeling of greasiness of other oils in your products, increases spreadability, and will solubilize other oils and silicones in an oil based product. It's also a fragrance fixative, so adding it to something like a body oil or oil based perfume spray will help the scent stick around longer! It's described as having a "silky soft after feel" and is occlusive without feeling heavy.

C12-15 alkyl benzoate is considered "oil free", so those of us who can't normally use oils on our face due to comedogenicity issues can use something like C12-15 alkyl benzoate to create oil free moisturizers and foundations (and C12-15 alkyl benzoate is considered outstanding as a mineral make-up ingredient thanks to its solubilizing abilities).

C12-15 alkyl benzoate is considered very poor on the spreadability scale, with high surface tension and low viscosity, but this is only when you compare it to other esters. If you compare it to a light oil - let's say sunflower oil - it's a very good spreading emollient. It is also high polarity, hence the ability to solubilize the other oils or silicones in a product.

You might see C12-15 alkyl benzoate under the trade names Crodamol AB or Tegosoft TN. 

How can we use C12-15 alkyl benzoate in our products? As you saw in yesterday's post, we can use C12-15 alkyl benzoate as a substitute for other light oils in our products. In this cream cleanser for normal skin (or the cream cleanser for dry skin), I use C12-15 alkyl benzoate as one of the oils in the product to offer moisturizing and emolliency to the product. (And yes, I have rosacea prone, oily skin and it feels quite nice!)

Because it offers occlusion without heaviness, using C12-15 alkyl benzoate is a good way of getting the occlusive powers of something like shea butter in a lighter feeling lotion. I had planned to leave the butters out of this recipe - the trying new things out lotion - because I was in the mood for a very light, easily spreadable lotion, but the lure of my new matcha green tea butter was too much and I included it in the end. But the C12-15 alkyl benzoate would have been enough for the intended purpose - a light, spreadable lotion that offered an occlusive layer. And I used it in the complicated balm to offer a nice level of emolliency without adding a ton of weight!

Let's take a look at using esters in a basic anhydrous butter tomorrow - a whipped butter!


Anonymous said...

i wana know why does my cream of 20% herbal extracts separates into 2 phases again after 3 days ..?? the extracts are aloevera , olive leaf extract ...never separated befor using i.p.m

Susan Barclay-Nichols said...

I'm afraid I can't answer your question without the recipe and process you followed. If you added something like 2% IPM without altering the amount of emulsifier, that might be enough to destabilize the emulsion. If you aren't heating and holding, if you aren't using enough emulsifier, if you don't get the two phases to the same temperature - there are many reasons why a lotion might not work, and I can't really offer any specific advice without the recipe and process.

Gwen Baldwin said...

Hi Susan, I've been wanting to try the complicated balm. I can't seem to find a supplier that has all the ingredients. Have you any ideas?
Thanks, Gwen

Susan Barclay-Nichols said...

Hi Gwen. I've purchased all my esters from the Personal Formulator (here's the link for the oils section). I don't know of anywhere else that might carry all of them in one place.

If you're going to make the complicated balm, you have to try the hand lotion with esters or the body lotion with esters - I love both of these so much! Or the body oil! Can you tell I love esters!

Anonymous said...

Awesome Blog! Thanks so much for all of this information. It's so nice to see someone put up all of their expertise like this. Thanks!!

Anonymous said...

Hi Gwen, Are there any health risks associated w C12-15 alkyl benzoate? My wife is pregnant and we want to be safe w all her cosmetics.

Lowell in Malibu

Susan Barclay-Nichols said...

Hi Lowell. I'm not sure who Gwen might be - a previous commenter, by the looks of it - but I'm Susan or Swift!

I haven't found any health risks associated with C12-15 alkyl benzoate. It's an ester, and it's been used in many many body care products for a long time. I would happily use it on my friends or family who were pregnant or nursing!

storm said...

Thanks for the info! I'm trying to look into all the ingredients in a new cream I found!

chanelll888 said...
This comment has been removed by the author.
chanelll888 said...

Hi Susan! I heard that C12-C15 Alkyl Benzoate is an spf booster in sunscreen. If my formula is to achieve spf 30, will the spf increase? How many percent? I have been looking for a clinical study to support this claim. I would really appreciate your input on this. Thank you in advance!

Anonymous said...

For those in the uk now sells c12-15 alkyl benzoate.


Anonymous said...

Ok... without sounding dumb... what exactly is an ester... I'm trying to dissect some ingredients- but a ester is considered a chemical am I wrong?or a "formula" of chemicals?

C12-15 alkyl benzoate is derived from what exactly?

I have incredibly sensitive skin and have been trying to narrow down what it is I seem to be reacting to as I use mostly plant based and naturally based products- I'm trying to dissect naturally based products to see if they are actually "natural" before I use them! Thank you

Susan Barclay-Nichols said...

Hi Anonymous. Could you please put your name on your comments in the future? Otherwise, I will have to delete them.

Here's a post on esters - The chemistry of esters. Check out the Esters & fragrances post).

As a thought, consider that natural doesn't always mean safe or non-reactive. I have acne prone skin, and I don't break out using esters, but I do using vegetable and seed oils. An ester might not necessarily found in nature, but this doesn't mean that it isn't safe or that it will make you react adversely.

Aline Huntly said...

Aloha Susan,
I am trying to understand the different effects of alkyl esters, cetyl esters and jojoba esters. Do you have any pointers?

Aline Huntly said...

Hi again,
I am thinking about using Alkyl Esters with Fractionated Coconut Oil as a fragrance base and I'm wondering what proportion would be good?
BTW the link to the Esters & Fragrances post does not work (and I couldn't find the post by searching).

Aline Huntly said...

Has anyone here used esters as a fixative??

Susan Barclay-Nichols said...

Hi Aline. Alkyl esters are just a generic name for esters, so cetyl esters would be a type of alkyl ester. (I'm not sure if jojoba esters are alkyl esters off the top of my head, but I think they are.) The cetyl esters I've used come in a flake format. (Take a look at the post on cetyl esters to see pictures of the stuff I have.) Jojoba esters come in all kinds of different viscosities, so you'll want something that's thin.

I have used C12-15 alkyl benzoate as a fixative in my body oils at around 10% or so.

Aline Huntly said...

Thanks Susan.
I did not know that about Alkyl Esters being a blanket term. I meant to ask re the differences between C12-15 alkyl benzoate, cetyl esters and jojoba esters in terms of how they behave in a lotion (but my question was not very clear).
I will try C12-15 alkyl benzoate at 10%. I have tried ppg-20 methyl glucose ether as a fixative and have not noticed any difference....

Myoc said...

Hello. Im Allie.
I dont have alkyl este here so can i use triglyceride or jojoba oil as the replacement?
Thanks alot, allie

clfisher said...

Can 12-15 Alkyl Benzoate be used as a solvent for natural vanillin? The supplier suggested Ethyl Alcohol, but I do not want to use this, and I have Alkyl Benzoate in inventory.
If not, is there another alternative to use as a solvent?

Thank you very much

Susan Barclay-Nichols said...

Hi clfisher! You can try it and see what you think. My suggestion is to do a search to see what kinds of solvents might work. A quick Google search uncovered this study that might interest you.