Colorants for High pH CP Soap

Asked by: pupupunim On: December 17, 2022 Product Type: Cosmetics

Question

I am making Cold Process (CP) soap and need recommendations for colorants, specifically orange and red, that are stable and do not change color or fade in the high pH environment of CP soap, as the colors I have used previously have distorted.

Answer

For Cold Process (CP) soap, which has a high alkaline pH, choosing colorants that are stable in alkaline conditions is very important to prevent color distortion or fading.

Based on the information found, there are some colorants that should be suitable for use in CP soap and have fade-resistant properties:

  • Orange: We recommend D&C Orange No.4 (CI 15510) EasyWash™. This is a water-soluble orange colorant specified as a special type that is non-staining (Easy to Wash) and resistant to fading.
  • Red: There are several options in the EasyWash™ series that are interesting, such as:
    • Ponceau 4R (CI16255) EasyWash™
    • D&C Red No.33 (CI17200) EasyWash™
    • FD&C Red No.4 (CI 14700) EasyWash™

      Colorants in this group are water-soluble and are stated to be fade-resistant, which is a desired property for CP soap.

In addition to the EasyWash™ colorants, generally, Pigment type colorants like Iron Oxides (red, yellow, black, brown) are also popular and highly stable in CP soap.

We recommend testing the colorants in small amounts in a small batch of CP soap first to check the color stability before full-scale production.