Wednesday, April 27, 2011

Question: How do we know the correct HLB value of oils and butters?

Melian poses some very interesting questions in this post, and I thought they needed to be answered here! Bear with me as this is a really long post (not that I'm the Queen of Succint-land on normal days, but this one seems really long!)

I'm finding disagreements on the hlb of a few oils. how do we know what is the correct value? Specifically,:
Mango Seed Butter 8
Mango (Mangifera Indica) Seed Oil [RHLB = 7 ± 1]

Meadowfoam Seed Oil 6.5
Meadowfoam (Limnanthes Alba) Seed Oil [RHLB = 6 ± 1]

Myristyl Myristate 8.5
Myristyl Myristate [RHLB = 7.52 ± 1]

Jojoba Oil 6.5
Jojoba (Buxus Chinensis) Oil [RHLB = 6 ± 1]

Cyclomethicone 7.75
Cyclomethicone [RHLB = 7.5 ± 1]

How do we choose?

If you look at the values you've posted, a lot of them are with in the +/- range. For instance, if mango butter is 7 +/- 1, then it could be 6, it could be 8. With meadowfoam seed oil listed as 6 +/- 1, 6.5 falls into that range. And so on.

HLB values for our emulsifiers is determined theoretically and experimentally. Required HLB values are determined experimentally, which is to say that each batch of oil must be tested and the HLB value must be calculated. Vegetable and animal oils can vary a lot between regions, seasons, climates, and variations of crops. For instance, a sunflower might go through a cold patch and produce more of one fatty acid or more phytosterols than the last crop from this field, and this could alter the HLB value for that entire harvest. Does the company distributing the sunflower oil test the required HLB every time? Probably not.

If you read any of the oil or butter posts I've written for this blog, you'll always see ranges for things like fatty acids, phytosterols, tocopherols, and polyphenols as opposed to something very specific. If we take a look at sunflower oil, you'll see it contains 5 to 7% palmitic acid, 3 to 6% stearic acid, 16 to 36% oleic acid, and 61 to 73% linoleic acid. If you have a batch with 73% linoleic acid and one with 61% linoleic acid, this could change the required HLB value for the batch. 

This variation in natural ingredients is one of the reasons cosmetic chemists use mineral oil and esters a lot. Mineral oil is always mineral oil and the same product from the same manufacturer will have the same required HLB every time.

Under the theory of HLB, all castor oils should have the same HLB (HLB 14), but they don't because there are so many things that change between each batch. (Ironically, I haven't seen castor oil listed as anything but 14, but it's the one I wrote down repeatedly while consulting different charts.)

This brings us to a very different discussion, which is how do we know which numbers are accurate and if all those calculations we've been doing have any point? We're trying to get these really accurate figures for an emulsifier, but then it turns out we could be out by quite a lot if you consider that +/- part! For instance, I found lanolin listed as 9 in one PDF, 10 in LabRat's PDF, and 12 in this PDF from Zenitech. How will this affect my calculated emulsifier if I'm going with 9 one day and 12 another day? If I'm using lanolin at 10% of a 30% oil phase (so it makes up 0.33) I could be out by 1 in my required HLB (2.97 vs 3.96)!

So what's the point of being all accurate and coming up with a figure that is only off by 0.1 or so for my emulsifier if my oil values could be wrong? This is kind of a rhetorical question, but it is the reason I tend to use all-in-one emulsifying systems like Polawax, BTMS-50, Ritamulse, and so on more often than I use the HLB emulsifiers. As much I like the ability to roll-my-own and not be dependent upon companies that don't seem to appreciate homecrafters (you know which companies I mean!), it's very frustrating to think that all that hard work in calculating required HLB values and emulsifiers might be completely wrong! With something like Polawax, you don't need to calculate the HLB of anything - just make sure you're using 25% of the oil phase and you're likely to get a great emulsification!

Yes, I realize I've just made an argument for not learning the HLB system when I still have at least one more post on the topic, but there are great reasons for using it, including less reliance on big companies when they change their formula for the product, lower cost for these emulsifiers, and the pride that comes in knowing you've learned something new and can use it! I have used the required HLB values from Convergent Cosmetics: Emulsions & the HLB system PDF for the last few years and the only time I've had a lotion fail is when I've failed to do something right like heat and hold for 20 minutes, pouring the water phase into the oil phase, or when I've messed up the values big time!

Melian continues...There are more. On your blog you said that squalane was 12 to 12.9. Another source said it is 7 plus or minus 1. is squalane like lecithin and varies? Also, is lanolin 10 or 12? the pdf you cited says 10 but this information says 12. How do we know who to believe?

I think I found the HLB value of squalane at Lotioncrafter (click here for link). But then I find this link (do a search for squalane when on this page and you'll find it) that says it is 9.5. I wonder if there are different types with different levels of hydrogenation, because this would give it different HLBs for different types. I'm really not sure how to answer this question. Interestingly enough, I found some information on squalene that indicates that "a required HLB value for squalene has not been reported in the literature" (note this is squalene, not squalane).

As a side note, the reason lecithin varies is due to the degree of hydrolysis and extraction methods. Hydrolysis is when a molecule is split into two parts by the addition of water. Sometimes an acid or base catalyst is used in the process. Saponification is the hydrolysis of a fat (our oils and butters) with a base like sodium hydroxide. In the end, we get soap!

I'm really not sure who to suggest you trust when it comes to finding required HLB values for oils. I turn to this PDF first for my HLB values and companies like Lotioncrafter under their specific ingredient listings. But considering that required HLB values are determined experimentally, every batch of olive oil could have a different value, so it could vary from supplier to supplier. It's hard to know the exact HLB values for natural oils and butters, so it could vary by as much as -1 to +1.

Silicones are a different story - and this post is already really really long! There can be variations between the weight of each silicone. For instance, I have two dimethicones - dimethicone 350 c.s. and dimethicone 1000 c.s. (c.s. stands for centistokes and the higher the number, the thicker the dimethicone. Click here for more information.) Although these are both called dimethicone, they may have slightly different HLB values based on the viscosity of the product. (If you want to know more about the 3D HLB system as it relates to silicones, check out the powerpoint presentation found here or the PDF found here).

Okay, this is way too long so I'll stop here. I'm sure there are more questions out there and I'll do my best to answer them! Those of you who are experts in the HLB system, feel free to comment away! The more information we have, the better!


melian1 said...

thank you, thank you! the explanation makes sense. so for our figuring, do you recommend we simply take the center of the range for our figuring?

should we up the % of emulsifier used in order to compensate? for instance, if we were going to use 4% emulsifier for the particular recipe, we could use 4.5%?

Sânziene şi Mătrăgună said...

great post. I have the same issue - so I am using the "mean" required HLB value, and the emulsifier blend amount is 1/4 of total oils. And I prefer to add some additional thickener, such as Na Carbomer, Xanthan, HEC. Or simply increase the % of emulsifiers.

Say that I get after calculating the required HLB for my recipe :

1.26 % glyceryl stearate
2.03% methyl glucose sesquistearate.

I just use 1.3 glyceryl stearate and 2.2 methyl glucose sesquistearate and 0.2% xanthan gum (or I omit the xanthan gum is my oils list already has some lanolin alcohol, cocoa butter, cetyl/cetaryl alcohol etc.). Recenlty I developed a passion for Na carbomer, so I try to stay away from salts and use .5 - 1% Na carbomer in water phase.


crab legs said...


I'm trying to emulsify something that doesn't have a listed HLB value. It's non-polar, and I know the molecular structure, but how would I begin to determine a theoretical HLB value for it? Many thanks!