The HLB System – Choosing Which Surfactant to Use in Your Formulation – Saffire Blue Inc.
Formulation Tools & Guidelines Vegetable Oils

The HLB System – Choosing Which Surfactant to Use in Your Formulation

Emulsions are one of the most common forms of cosmetic products.  If you are formulating an emulsion, such as a cream or lotion, the HLB (Hydrophile-Lipophile Balance) System is particularly useful to identify which surfactant to use for optimal oil and water emulsification.

What is HLB?

HLB is a number system that lets you know how oils and surfactants will likely interact.  Surfactants have an HLB value – the higher the number the more hydrophilic (water soluble), the lower the number the more lipophilic (oil soluble).  Oils and applications have an HLB requirement. Matching the HLB value with the HLB requirement will give good performance.The HLB system: Choosing Which Surfactant to Use in Your Formulation

< 10 : Lipid-soluble (water-insoluble)
> 10 : Water-soluble (lipid-insoluble)
1.5 to 3: Anti-foaming agent
3 to 6: Water-in-oil emulsifier
7 to 9: Wetting and spreading agent
12 to 16: Oil-in-water emulsifier
13 to 15: Detergent
15 to 18:  Solubiliser or hydrotrope

How is knowing the required HLB useful?

Choosing a surfactant for your oil-in-water emulsion can be made easier using the HLB system. The HLB value of the surfactant that provides the lowest interfacial tension between your unique oil phase and your unique water phase is your required HLB. The correct HLB value usually translates to superior stability at a lower use level.  Knowing the required HLB of an oil or an oil mixture means that you can use the least amount of surfactant to achieve emulsification.

Calculating HLB

First you must determine which are the oil soluble ingredients in your formula, not including the emulsifiers.  Next, weigh each of the weight percents of the oil phase ingredients together and divide each by the total.  Multiply these answers times the required HLB of the individual oils.  Add these together to get the required HLB of your unique blend.

Example:

Sample Oil-in-Water lotion formula

  • Mineral oil 8{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Caprylic/capric triglyceride 2 {2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Isopropyl isostearate 2{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Cetyl alcohol 4{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Emulsifiers 4{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Polyols 5{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Water soluble active 1 {2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Water 74 {2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Perfume q.s.
  • Preservative q.s.

Add up the oil phase ingredients

  • Mineral oil 8{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Caprylic/capric triglyceride 2{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Isopropyl isostearate 2{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
  • Cetyl alcohol 4{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}

Total: 16{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}

Divide each by the total to get the contribution to the oil phase:

Mineral oil: 8 / 16 = 50{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
Caprylic/capric triglyceride: – 2 / 16 = 12.5{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
Isopropyl isostearate: – 2 / 16 = 12.5{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}
Cetyl alcohol – 4 / 16 = 25{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}

Multiply by the required HLB of the oil:

Mineral oil: 50.0{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} * 10.5 = 5.250
Caprylic/capric triglyceride: 12.5{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} * 5 = 0.625
Isopropyl isostearate: 12.5{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} * 11.5 = 1.437
Cetyl alcohol: 25.0{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} * 15.5 = 3.875

Add all values:

Total required HLB = 11.2

So for this formulation, you would want to use a surfactant that has a value of approximately 11 to achieve the best emulsification.

Using Multiple Surfactants

HLB values are additive, so if the use of two different surfactants is desired, the HLB will be the weighted average of the HLB values for each product. For example, if you require an oil with an HLB of 11 in your formula, you could use 50{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} of a surfactant with an HLB of 12 (50{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} of 12 = 6) and 50{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} of a surfactant with HLB value of 10 (50{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473} of 10 = 5). Total HLB = 6 + 5 = 11.

So Which Surfactant Do I Choose?

Although it is a good starting point, the HLB system is not the absolute predictor of the behavior of your emulsion. Additional ingredients in the formula are not taken into account, but may impact the stability of the emulsion. The HLB method also does not calculate exactly how much surfactant is needed, but a good starting point is 2 to 4{2f217b6ef4e944ec449aa2c625e1f0e1f43c0ee840d0a16b8bf46c3ef1173473}.

Below are the recommended HLB values of surfactants in various formulas:

  • Mixing unlike oils together
    • Use surfactants with HLB of 1 to 3
  • Making water-in-oil emulsions
    • Use surfactants with HLB of 4 to 6
  • Wetting powders into oils
    • Use surfactants with HLB of 7 to 9
  • Making self-emulsifying oils
    • Use surfactants with HLB of 7 to 10
  • Making oil-in-water emulsions
    • Use surfactant blends with HLB of 8 to16
  • Making detergent solutions
    • Use surfactants with HLB of 13 to 15
  • For solubilizing oils (micro-emulsifying ) into water
    • Use surfactant blends with HLBs of 13 to 18

We’ve also compiled a list of HLB values and required HLBs that you may find useful, if considering this calculation method for your emulsions:

View the list of HLB values for Emulsifiers

View the list of Required HLBs for Carrier Oils and Lipids

 

3 Comments

  • Just tried clicking on the 2 links at the bottom on the HLB System article and says “page cannot be found”. Will you have these lists posted soon?

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