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
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.
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!
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