Two Preservative Systems

Just a general question for you guys. Can I use TWO preservative systems in a cream or serum? I was thinking Neoguard and Optiphan. I emailed the supplier and she said that I absolutely can. I know some of you may be wondering why I want to use two, I just ear on the side of caution. (I know I can't use this for something like a vitamin C serum, I am just asking in general...)

So please let me know if this will be okay. Also, what would you guys recommend in terms of % of each one? Perhaps the midpoint of the recommendation of each chemical?


  • PerryPerry Administrator, Professional Chemist
    Yes, you can use two preservative systems.
  • ozgirlozgirl Member, PCF student
    Just make sure if you are using two preservative blends that they don't have the same components or if they do that you don't exceed the maximum permissible concentrations for each individual component.
  • MarkBroussardMarkBroussard Member, Professional Chemist

    The answer is "Yes, but" ...

    Most preservatives are generally broad spectrum agains bacteria, yeast & mold, but many preservatives are primarily bacteriocides or fungicides ... strong against bacteria, but weak on yeast/mold or vice-versa.

    So, you best look at your selection of preservatives as complimenting each other.  Combine a preservative that is strong against bacteria, but weak on yeast/mold with a second preservative that is strong on yeast/mold.

    There is little point in combining two preservatives that are both strong on bacteria, but both weak on yeast/mold.

    Generally, yeast/mold will be your most likely fail point in preservation, so make sure you add a strong fungicide.   

    See website for details
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