Home Cosmetic Science Talk Formulating Shampoo Concentrate - Preservative question

  • Shampoo Concentrate - Preservative question

    Posted by AutumnBlum on September 23, 2019 at 10:11 pm

    I’m planning to make a shampoo concentrate where the end-user can add water.  I’m hoping to have a 5:1 dilution or let the user add 20% concentrate and 80% water.  So thinking I need 5 times the amount of preservative to keep this safe.  BUT… government regulations don’t allow that high of a preservative concentration in a finished product.  I’d appreciate some thoughts on how much preservative to concentrate!  I’m currently using Geogard Ultra at 2% in the diluted product.  Thank you!

    AutumnBlum replied 4 years, 7 months ago 3 Members · 3 Replies
  • 3 Replies
  • chemicalmatt

    Member
    September 24, 2019 at 7:25 pm

    The diluted product IS the finished product as applied to humans, so you are OK as long as you do the math right.  More importantly is your solubility limit with that preservative blend. Can 10% even stay soluble? Good ‘ol Kathon should solve that problem: 0.25% should go into that easily.

  • belassi

    Member
    September 24, 2019 at 11:10 pm

    The active ingredients in KATHON™ CG Preservative are isothiazolinones 
     :'(   :#  
    UNDER NO CIRCUMSTANCES.

  • AutumnBlum

    Member
    October 8, 2019 at 5:52 pm

    Sorry for my slow reply and thank you for the responses!  Definitely couldn’t use Kathon in our formula.  The Geogard does go into solution and so far hasn’t settled out (thanks for that tip to watch for!)

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