Saturday, February 21, 2015

Weekend Wonderings: What's that whitening effect with lotions?

In this post on Lotionpro 165, Michelle asks: I had some whitening when using Lotionpro (at 4%) and it was suggested that it was reacting with my fatty alcohols (2% behenyl, 1% cetyl). Have you noticed this?

I haven't noticed it with this emulsifier, but I admit that I'm not that bothered by what's called the soaping effect. The fatty acids in the lotion, combined with an alkaline ingredient like triethanolamine or potassium hydroxide, create a soap, which acts as the emulsifier in your lotion. (A common combination is triethanolamine and stearic acid.) If you're using a stearate or oleate based emulsifier, you are bringing the water and oil together in your lotion by creating a soap, which is going to leave those white streaks when you apply it. In the case of Lotionpro 165, you're using Glyceryl Stearate and PEG 100 Stearate to create an emulsion.

How can you get rid of this? You can add some dimethicone or change emulsifiers! Or just accept it!

Related posts:
What is the "soaping effect"?

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