Home Cosmetic Science Talk Formulating Preservative selection for shampoo

  • Preservative selection for shampoo

    Posted by Abdullah on April 28, 2021 at 10:40 am
    Please help me choose a good and mild preservative blend for shampoo. 

    Which one is the mildest formaldehyde releaser and which one is the most effective for bacteria?
    How is that compared to phenoxyethanol in effectiveness and mildness?

    I will combine it with a fungicide. Options are caprylhydroxamic acid, Piroctone Olamine, sodium dehydroacetate, sodium benzoate. Which one do you recommend?

    Any other suggested preservative blend?

    This is the shampoo formula in Active ingredients:
    SLES   %9
    CAPB  %1.5
    APG    %1.5
    PQ10  %0.3
    Glycol distearate  %2
    HPMC %0.5
    EDTA  %0.2
    EO    %0.4

    pH 5

    Abdullah replied 3 years, 1 month ago 2 Members · 6 Replies
  • 6 Replies
  • PhilGeis

    April 28, 2021 at 10:47 am

    Can’t address mildness but for efficacy suggest Germall or Glydant with sodium benzoate and EDTA.

  • Abdullah

    April 29, 2021 at 2:59 pm

    @PhilGeis thanks
    The upper limit for DMDM hydantoin is %0.6, so why warning above %0.05?

     Finished products containing DMDMH must be labeled with the

    warning “contains formaldehyde” if the (free) formaldehyde
    concentration exceeds 0.05%
  • PhilGeis

    April 29, 2021 at 3:03 pm

    Right - DMDm Hydantoin at 2000-2500 ppm usually gave < 500 ppm free formaldehyde.  “Free” is important.  

  • Abdullah

    April 30, 2021 at 1:45 am

    @PhilGeis Formalin is %37 formaldehyde in water, is that %37 free formaldehyde? 

  • PhilGeis

    April 30, 2021 at 9:49 am

    But to make it complicated - formaldehyde is a gas and formalin is a saturated solution of that gas.  The gas hydrated in solution as methylene glycol. 

    One more that you need to consider.  Formalin includes methanol -maybe 10%.  Please take that into consideration

  • Abdullah

    April 30, 2021 at 3:26 pm

    @PhilGeis thanks a lot

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