Saturday, April 23, 2011

HLB system: A demonstration (part 1)

So how do we use the HLB system to create an emulsifier? Click here for a great PDF with all the required HLB values of our oil phase ingredients and the HLB values of our potential emulsifiers. You will need to refer to this to play along!

The steps to finding out the HLB value of your ingredients.
1. Which ingredients have an HLB value?
2. How much of each ingredient is in the total recipe?
3. Divide this by the total oil phase to get a percentage.
4. Multiply the percentage by the HLB value. Add them together to get the HLB value of your oil phase.

The steps to finding out the HLB value of your emulsifiers.
1. Find a low HLB emulsifier and a high HLB emulsifier.
2. Work on the percentages to find a total that is very close to the HLB value of your oil phase.
3. Rejoice!

So let's take a recipe at random and figure out the required HLB values of the oil phase ingredients and the HLB values of the emulsifiers and create our own emulsification system! How about Lush's Afterlife Moisturizer?

STARTING OUT RECIPE FOR DUPLICATING LUSH'S AFTERLIFE
HEATED WATER PHASE
55.5% water
3% glycerin
2% honey

HEATED OIL PHASE
7.5% emulsifier
3% stearic acid
1% cetearyl alcohol
2% coconut oil
9% olive oil
5% evening primrose oil
5% avocado oil
5% wheat germ oil

COOL DOWN PHASE
0.5% preservative (I'm using liquid Germall Plus)
0.5% powdered mango extract
1% fragrance or essential oil (optional in a facial product)


1. Which ingredients have an HLB value?
Look for anything oil soluble. In this case, all of the oil soluble ingredients are found in the oil phase. (Sometimes we have to look to the cool down phase for things like silicones, which also have an HLB value.) Most of our carrier oils have an HLB of 7 and most of our butters have an HLB of 8.
  • stearic acid - HLB value 15
  • cetearyl alcohol - HLB value 15.5
  • coconut oil - HLB value 8
  • olive oil - HLB value 7
  • evening primrose oil - HLB value 7
  • avocado oil - HLB value 7
  • wheat germ oil - HLB value 7
2. How much of each oil soluble ingredient is in the recipe?
3% stearic acid
1% cetearyl alcohol
2% coconut oil
9% olive oil
5% evening primrose oil
5% avocado oil
5% wheat germ oil

Total up these numbers and you'll find our total oil phase is 30%. (We don't count the emulsifier from the original recipe as we're trying to replace that!)

3. Divide by the total oil phase to see how much each ingredient makes up in the oil phase. 
Our oil phase here is 30% of the total recipe, so we'll be dividing each ingredient by 30 to figure out how much of each oil is in this oil phase.

3% stearic acid - 3/30 = 0.1 or 10% of the oil phase
1% cetearyl alcohol - 1/30 = 0.0333 or 3.3% of the oil phase
2% coconut oil - 2/30 = 0.0666 or 6.6% of the oil phase
9% olive oil - 9/30 = 0.3 or 30% of the oil phase
5% evening primrose oil - 5/30 = 0.1666 or 16.67% of the oil phase (round to 16.7%)
5% avocado oil - 5/30 = 0.166 or 16.67% of the oil phase (round to 16.7%)
5% wheat germ oil - 5/30 = 0.166 or 16.67% of the oil phase (round to 16.7%)

Make sure the total of the percentages equals 100%. Yep, with the rounding it does!

Note: Remember that a percentage also has a decimal value. For instance, 30.5% is equal to 0.305 (move the decimal two spaces to the right to get the percentage!) These are the values you want to work with in the rest of the phases.

4. Multiply the numbers from step 3 with the HLB values you found in step 1. 

Stearic acid - HLB value: 15. Makes up 0.1 of the oil phase. 0.1 x 15 = 1.5
Cetearyl alcohol - HLB value: 15.5. Makes up 0.033 of the oil phase. 0.033 x 15.5 = 0.5115
Coconut oil - HLB value: 8. Makes up 0.066 of the oil phase. 0.066 x 8 = 0.528
Olive oil  - HLB value: 7. Makes up 0.3 of the oil phase. 0.3 x 7 = 2.1
Evening primrose - HLB value: 7. Makes up 0.167 of the oil phase. 0.167 x 7 = 1.169
Avocado oil - HLB value: 7. Makes up 0.167 of the oil phase. 0.167 x 7 = 1.169
Wheat germ oil - HLB value: 7. Makes up 0.167 of the oil phase. 0.167 x 7 = 1.169

Add these numbers together we get a required HLB of 8.1465 (which you can round up to 8.15).

CHOOSE YOUR EMULSIFIERS
So now we have to choose our emulsifiers. Choose a low HLB emulsifier and a high HLB emulsifier from the list (found in this PDF on page 10).

In my workshop, I currently have the following emulsifiers:
glycol distearate - HLB 1
glyceryl stearate - HLB 2.9
laureth-4 - HLB 9.7
oleth 10 - HLB 12.4
ceteareth-20 - HLB 15.2

I think I'll try two different combinations - glycol distearate and ceteareth-20 and glyceryl stearate and oleth 10.

We're going to multiply the percentage of emulsifier needed by the HLB of the emulsifier to figure out the number. We will have to adjust it to get to the required HLB of 8.15.

GLYCOL DISTEARATE AND CETEARETH-20
This is a fairly common combination and easy to work with because the HLB of glycol distearate is 1, making for easier math. I'm going to use 4% of this emulsifier in the lotion.

I've chosen 4% because I know this is what works for me. LabRat suggested 2%, but I find there's too much room for error with my scales that only go to 0.1 gram weights! You can go higher or lower if you want, but I'm working with a total emulsifier amount of 4%.

My required HLB for this lotion is 8.15.

If I use 50% glycol distearate (0.5 x 1 = 0.5) and 50% ceteareth-20 (0.5 x 15.2 = 7.6), I'll have an emulsifier with an HLB value of 8.1. That really is close enough.

So I need 50% glycol distearate and 50% ceteareth-20 in my 4% emulsifier. (Normally I'd multiply 0.5 x 4 = 2 to figure out how much emulsifier, but it's really very simple here!) So I'll use 2% glycol distearate and 2% ceteareth-20.

Wow, that was easy. And it was a fluke! I have been doing the math as I go along in this post, so I didn't choose this recipe for ease of use! 

GLYCERYL STEARATE AND OLETH-10
This one's going to be slightly harder because glyceryl stearate has an HLB value of 2.9 and oleth-10 has an HLB value of 12.4.

My required HLB for this lotion is 8.15.

I always start with 50% of each emulsifier.
Glyceryl stearate - 0.5 x 2.9 = 1.45
Oleth-10 - 0.5 x 12.4 = 6.2
Total is 7.45, which isn't high enough. I need more oleth-10 and less glyceryl stearate.

Let's try 40% to 60%.
Glyceryl stearate - 0.4 x 2.9 =1.74
Oleth-10 - 0.6 x 12.4 = 7.44
Total is 8.18, which is almost dead on the amount we need.

So if we use 40% glyceryl stearate and 60% oleth-10 as our emulsifiers, we'll get the right amount!

If I'm using a total of 4% emulsifier, I'll need 1.6% glyceryl stearate (0.4 x 4) and 2.4% oleth-10 (0.6 x 4) as my emulsification in this product.

An aside: When I'm figuring out the emulsifiers, I make up a messy little chart like this one to the left. I start off at 50% for each emulsifier, then go to 51% and 49% or 60% and 40%, depending upon what I need, until I get the amount I want. If this doesn't work for you, click here to download my HLB spreadsheet in Excel format and see if that helps!

So let's take a look at the final recipe.

STARTING OUT RECIPE FOR DUPLICATING LUSH'S AFTERLIFE WITH HLB EMULSIFIERS
HEATED WATER PHASE
59% water
3% glycerin
2% honey

HEATED OIL PHASE
4% emulsifier (2% glycol distearate and 2% ceteareth-20 or 1.6% glycol distearate and 2.4% oleth-10)
3% stearic acid
1% cetearyl alcohol
2% coconut oil
9% olive oil
5% evening primrose oil
5% avocado oil
5% wheat germ oil

COOL DOWN PHASE
0.5% preservative (I'm using liquid Germall Plus)
0.5% powdered mango extract
1% fragrance or essential oil (optional in a facial product)

Notice I increased the water phase to make up for the reduction of 3.5% emulsifier from the original recipe. If you aren't sure why I did this, click here for a post on the topic of increasing water phases when you decrease oil phases.

If you're interested in seeing another example, please click here for lotion and here for body butter! Or join me tomorrow for more fun with the HLB system!

9 comments:

zaczarowany pierniczek said...

Hi!
I think it's easier to calculate how much each emulsifier you need using formula x*2,9 + (1-x)*12,4 = 8,15 instead of trail end error method or messy chart as you called it.
We have 34% of oil phase in this recipe but only 4,5% of emulsifer, which is about 13% of oil phase. Isn't it too little, shouldn't be 20-20%?

Susan Barclay-Nichols said...

I think the trial and error/messy chart is more effective in this situation for two reasons - one, because enough people are scared of math and a formula like that will chase just about everyone away from learning the HLB system and two, because the trial and error method teaches us a lot. For instance, you learn that if you're going for a lower number, use more of the lower emulsifier. By trying 50-50, 60-40, 40-60, you can see how the numbers change with the different emulsifiers. Once you get used to the system, then using a formula or a spreadsheet is fine. But I really do think we need to learn how to work it all out step by step so we get the process and learn how to do it properly.

I'm not really sure how to read your formula. Is the "," supposed to be a decimal place (.)?

There's no set in stone amount for how much emulsifier to use with the HLB system like there is for complete emulsification systems. LabRat used to suggest starting at 2% for every lotion or cream regardless of the oil phase: I've been using 4% to 5% in my HLB lotions and they have been stable. If you want to use more, use more. Learning the HLB system is about learning what works in your recipes!

zaczarowany pierniczek said...

"I'm not really sure how to read your formula. Is the "," supposed to be a decimal place (.)?"

Yes, sorry for that, in my country we use "," instead of "." so sometimes I forget to change this notation.

Now I'm confused about amount of emulsifier. I've remembered from your entry "E-mail question: Using Polawax in your creations..." that you recommended to use 25% of oil phase, and I've been sure we need to use at least 20% of oil phase (now I don't even know where this number come from) to get a stable emulsion. I guess I really need to read it again.
Is there a different rule regarding how much emulisifer to use when we use HLB system and when we use an emulsifer which doesn't required HLB?
Who is LabRat? Once I assumed he/she had a blog and I tried to find it but without success.

Susan Barclay-Nichols said...

The Polawax suggested amount is only for Polawax, not for any other emulsifier. There is no suggested amount for starting off an HLB emulsifier, but I've seen 2% to 5% suggested, which is why I suggest 4%. (Here's the post about Polawax, and we're supposed to use 25% of the oil phase of that specific emulsifier. This isn't applicable to any other emulsifier.

As for LabRat, he used to have Convergent Cosmetics, but he died about 6 years ago and the site is no longer in use. He was incredible. If you've been to the Dish forum, you'd have seen his posts! He was so helpful and inspired me to learn so much!

Alifa Aprilia said...

Hai Susan! :-D My name's Ifa n my major is Pharmacy. Woooww Thank you so much for make me understand about all that horrible thing (HLB lols). I was very confused, but after read your blog, Now i fully understand it :-D Thank youu Susan ^^

Tommorow im going to make face whitening cream for semi solid experiment. My lecture only gives me a task to make a face whitening cream and all i have to do is that making the recipe. I have calculate n choose n i choose span 60 (1,4%) and tween 60 (2,6%) for the emulsifiers, but im still not sure with the other materials precentage use. T_____T #sad

But anyway thanks for sharing the knowledges. I learn many things from ur blog. You write very good and is easy to understand it. Im very happy. Thank you.. Nice to meet u n this blog too ^^

I Chen said...

Hi, your blog has been helping so much, but for example I just want to make natural foot cream contains aloe vera extract liquid 5% and olive oil 5%, and vaselin album as the base. I also plan to add cetyl alcohol to make the cream thicker.
Will I also need 2 kinds of emulsifier? Or I can just use tween 60/80? Sorry I really start trying to mix and match natural DIY products and I stumble at this website after many readings...(still clueless :P)

Susan Barclay-Nichols said...

Hi I Chen! I don't know where to start with your comment, to be honest, so I'll start with my first thoughts. It sounds like you want to make a foot cream that contains aloe vera, olive oil, cetyl alcohol, and vaseline. You will need an all in one emulsifier, not a single emulsifier. You'll want to look for recipes that contain emulsifiers like BTMS-50, Polawax, e-wax, or Ritamulse SCG, to name a few. (Click here for a post on this topic.)

I guess my second question is this - why are you trying to create a recipe from scratch when there are so many good recipes that have been tried and tested? I don't think the wisest decision for a new bath & body formulator is to start making things and hoping for the best. Do a search for a foot lotion and make that recipe instead of making your own. I know I have a few on this blog. If you want to use water in a product, you will need an emulsifier and a preservative for the product. Consider whether or not you would prefer to make something that doesn't contain water.

As an aside, I don't think you would find many people who would think that vaseline is considered natural.

m. said...

Hi,
Please, can anybody help me! I'm looking for an HLB value of mustard oil. Can't find it anywhere...
Best regards!

ea3a126c-c492-11e5-8237-439e05fc6d2b said...

Aw, this was the first article I ever read of yours. The hundreds of hours I've spent on this site since.

(Okay, this comment is an excuse to see if I can use an old login for OpenID... I've been signing Nurse Miel but notification of replies would be nice seeing I comment relenttlesssly.)