Cosmetic Science Talk

Cosmetic Science discussion form. For people who want for formulate cosmetics and get advice from other formulators around the world.

Home Cosmetic Science Talk General Microbial/Preservative testing in cosmetics

  • Microbial/Preservative testing in cosmetics

    Posted by Herbnerd on May 26, 2022 at 12:18 am

    I haven’t been able to find the answer, it may be I’m looking in the wrong place or incorrect search terms.

    When conducting preservative efficacy tests, is there a particular standard you follow?

    For some historical reason we have been using the British Pharmacopoeia PET test protocols - but since we are manufacturing cosmetic do we need to conduct PET to a specific pharmacopoeia (ie BP or USP)?

    Bill_Toge replied 8 months, 2 weeks ago 4 Members · 11 Replies
  • 11 Replies
  • Bill_Toge

    Member
    May 28, 2022 at 9:55 pm

    ISO 11930 is the most rigorous method that’s generally recognised

  • Abdullah

    Member
    May 28, 2022 at 3:18 pm

    PhilGeis said:

    I’ve no specified number. My experience has been in shampoos and hand wash.

    This is also a Shampoo formula. Low surfactant and inexpensive.

  • PhilGeis

    Member
    May 28, 2022 at 11:31 am

    I’ve no specified number. My experience has been in shampoos and hand wash.

  • Abdullah

    Member
    May 28, 2022 at 1:04 am

    PhilGeis said:

    %

    Currently i am using
    185ppm formaldehyde as (formalin)

     0.45ppm CMI MI
     0.1%EDTA
     pH 5.1 in cleansing products. 

    My question was if the ratio of surfactants is 4/1/1 anionic/amphoteric/non-ionic, if total surfactant is 6%, we need to test for mold too. At what percentage of total surfactant at this ratio we don’t need to bother with mold?

    Package is flip top cap. 

  • PhilGeis

    Member
    May 27, 2022 at 5:37 pm

    %

  • Abdullah

    Member
    May 27, 2022 at 12:26 pm

    PhilGeis said:

    I’d test that one as prototype.

    Got it
    Thanks

    If this is the ratio, what percentage of total surfactants should be in system so that you would not bother with mold for surfactant products as a general rule? 

  • PhilGeis

    Member
    May 27, 2022 at 10:20 am

    I’d test that one as prototype.

  • Abdullah

    Member
    May 27, 2022 at 12:03 am

    @PhilGeis is it so only in surfactant products with high amount of anionic surfactant or any surfactant product?

    For example when a product has

    2% SLS
    2% SLES
    1% CAPB
    1% APG
    Total 6% active surfactant with 4% being anionic. 
  • Herbnerd

    Member
    May 26, 2022 at 6:09 pm

    @PhilGeis Thanks for that. We seem to be getting bogged down (mostly by a micromanaging manager) who is insisting we compare BP, EP, USP, ISO/TR 19838 etc. 

    I’ll see if I can get hold of a copy.

  • PhilGeis

    Member
    May 26, 2022 at 3:23 pm

    Yes - but I’d not bother with mold for surfactant products.

  • Abdullah

    Member
    May 26, 2022 at 3:23 pm

    @PhilGeis complete elimination of yeast & mold too in 7 days? 

  • PhilGeis

    Member
    May 26, 2022 at 11:02 am

    Suggest at minimum you use CTFA method.  In any case, preserve  for complete elimination in 7 days or less, not the %’s.