preservative for cosmetic product with pH>10


I have created a formula with more than 80% water, and need preservatives for a pH level 10-11
any suggestions?



  • You do not need a preservative for that pH but you will need new skin after you use it.
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
  • phenoxyethanol works well up to about pH 12

    1,2-diols (butylene, pentylene, caprylyl glycol etc.) are also pH independent
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • Thank you

  • If the product is a wash-off then the pH 10-11 will not be a problem. It is a common pH for saponified oil soap washes and soap bars.

    ISO 29621 (Second edition 2017-03) "Cosmetics — Microbiology — Guidelines for the risk assessment and identification of microbiologically low-risk products" covers the pH of formulations. It says "Liquid soaps with alkaline pH (pH 9,0 to pH 10,0) present an environment unfavourable for the growth of some microorganisms. Hair curl relaxers, due to their extreme pH (around 12), prevent the growth of virtually all microorganisms that would be likely to contaminate cosmetic products."

    However, we always carry out microbiol tests in our lab on every batch produced.

    Hope this helps.

    Dr. Mike Thair
    Cofounder & Chief Formulator
    Indochine Natural
  • pH 10-11 will damage skin or even hair on contact
    it's irresponsible to sell such a product, and you'll likely get sued or prosecuted.

    Just too dangerous for consumers, even for a concentrate product, supposed to be diluted before use.
  • Honestly, as @mikethair correctly points out, it is not unusual for a saponified product to be at a pH of 10 or so. In fact, dropping to a pH much lower will destabilize the product and in fact reverse the saponification reaction. Microformulation Cosmetic Consulting provides Custom Formulations for both large Commercial accounts as well as smaller entrepreneurs. We can provide Naturally compliant Formulations under the NSF, NPA, Whole Foods and USDA Organic Certifications.
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