Mining for Pearlizing Agent 

Dear Valerie: Why is it hard to find a cold-process pearlizing agent that doesn’t contain ethoxylated materials?  —Minny Pearl

Dear Minny:

Traditional methods of pearlization for surfactant systems usually involve adding glycol distearate. Once the formulation cools, the glycol distearate crystallizes in small platelets, appearing as tiny, pearl sheets. If you are heating up your cleanser during production, just a fraction of a percent will do the trick when added around 80°C. If you are not heating your cleanser up, nothing will do the trick. That is, unless you use a pre-made blend that already contains glycol distearate!

Glycol distearate is a hard wax with a high melting point. In order to incorporate it cold process, a raw material supplier will sell blends where they have pre-melted glycol distearate into another surfactant or ethoxylated material. The ethoxylated materials allow for better solubility into your formulation, as glycol distearate has a low HLB. 

If you don’t want ethoxylated materials, the cold process additives can be challenging since they typically contain ethoxylates. I have found one material by BASF that incorporates glycol distearate into an APG with glycerin. It works pretty well, but one must use around 3% for a strong pearl effect. 

You can also add a physical pearlescent or platelet like lauroyl lysine. The effect is not quite the same, however, and then you run into a modification in your performance haptics, which may be different or worse. 

Valerie George is a cosmetic chemist, science communicator, educator, leader, and avid proponent of transparency in the beauty industry. She works on the latest research in hair color and hair care at her company, Simply Formulas, and is the co-host of The Beauty Brains podcast. You can find her on Instagram at @cosmetic_chemist or showcasing her favorite ingredients to small brands and home formulators at simply-ingredients.com. Her email is: askvalerie@icloud.com.