Home Cosmetic Science Talk General Comparison of preservative efficiency at different pH.

  • Comparison of preservative efficiency at different pH.

    Posted by abdullah on November 30, 2021 at 9:00 am

    This data shows the MIC of a preservative blend at pH 5 and 7. It shows how much less preservative you need in pH 5 compared to pH 7 for bacteria. But it doesn’t show this comparison for fungi. 

    Can anyone tell that approximately how much will pH 4-5 increase the preservative efficiency compared to pH 7 for fungi.

    PhilGeis replied 2 years, 2 months ago 3 Members · 6 Replies
  • 6 Replies
  • PhilGeis

    Member
    December 2, 2021 at 11:06 pm

    Do not presume you need less due to MIC.   You should use a generally effective level in each application.

  • abdullah

    Member
    December 3, 2021 at 1:48 am

    @PhilGeis i am using the upper recommend level of preservative no matter what the pH is because i don’t do PET test yet.

    I just wanted to know how much does preservative efficiency improve at pH 4-5 compared to pH 7 in an appropriate

  • PhilGeis

    Member
    December 3, 2021 at 2:06 am

    really need to establish PET

  • graillotion

    Member
    December 3, 2021 at 3:08 am

    PhilGeis said:

    Do not presume you need less due to MIC.   You should use a generally effective level in each application.

    What do you think of that combo as a preservative?  I don’t use that product…but I do use all three of those ingredients (plus others) in my formulas….(plus all the other hurdles).

  • abdullah

    Member
    December 3, 2021 at 6:45 am

    About the combo, it is like this 
    1. 0.6% phenoxyethanol+0.25% caprylyl Glycol+0.15% hydroxyacetophenone.

    2. 0.7% phenoxyethanol+ 0.2% hydroxyacetophenone+0.1% caprylyl Glycol. 

    3. 0.5% phenoxyethanol+0.5% hydroxyacetophenone

  • PhilGeis

    Member
    December 3, 2021 at 11:00 am

    Think 0.5% phenoxy is enough.  The others are marginal - you need something better targeting fungi.

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