HYDROPHILIC-LIPOPHILIC BALANCE (HLB)

Anyone who has attempted to create a lotion or cream knows the importance of "emulsions". A stable emulsion creates a perfect cream or lotion; an unstable emulsion creates . . . nothing.

EMULSION

• A stable mixture of two or more immiscible liquids held in suspension by small percentages of substances called emulsifiers.

In other words, mixing two or more ingredients together that wouldn't normally stay together.

An example is a vinegar and oil salad dressing. Oil and vinegar don't mix. To emulsify the two ingredients, we add egg yolk which contains Lecithin, a natural emulsifier. When all three are combined, the dressing remains emulsified (blended).

Most emulsions fall into two different categories:

• Oil in water emulsions (Oil droplets surrounded by water.)
• Water in oil emulsions (Water droplets surrounded by oil.)

To combine oil and water you need an emulsifier. Each emulsifier molecule has two parts:

• One that loves water called Hydrophilic
• One that loves oil called Lipophilic

The balance of these two parts gives you the Hydrophilic-Lipophilic Balance (HLB) making your creams and lotions stable.

According to this system, all oils and emulsifiers have an HLB value. To successfully hold an oil in emulsion, you need to match the HLB value of the oil to an emulsifier with approximately the same HLB value. There are many methods, theories and tools used to create successful emulsions, the HLB system is just one tool available. Following is a chart of HLB values.