Home Cosmetic Science Talk Formulating Mold preservation with sodium benzoate

  • Mold preservation with sodium benzoate

    Posted by Bluebird on September 20, 2024 at 9:27 pm

    Does this look sufficient, in general?

    It’s a water based formulation, pH ~4.5.

    Not much obvious food-for-mold-or-bacteria ingredients in the formulation.

    Preservation plan-

    sodium benzoate 0.4% and propanediol 5%


    caprylyl glycol+1,2 hexanediol for bacteria.

    • This discussion was modified 1 month, 4 weeks ago by  Bluebird.
    Graillotion replied 1 month, 3 weeks ago 4 Members · 6 Replies
  • 6 Replies
  • Abdullah

    Member
    September 21, 2024 at 4:27 am

    It might be enough if it has enough caprylyl glycol+1,2 hexanediol. How much is there?

    Does it have chelating agent?

    • Bluebird

      Member
      September 21, 2024 at 4:42 am

      Hi, there is no chelating agent.

      Currently I’m testing with 0.5% of (caprylyl glycol and 1 2 hexanediol mix); the manufacturer recommends 0.5% but does not disclose the proportion of cap glycol and hexandiol, unfortunately. I am thinking of perhaps adding a bit more of hexanediol on top of this to be safer.

  • PhilGeis

    Member
    September 21, 2024 at 6:09 am

    What is formula, package and product? This would not be esp food in a shampoo.

    Generally, Na benzoate is ok - glycols are too low and needs a chelator.

  • Bluebird

    Member
    September 21, 2024 at 6:46 am

    It’s a very watery toner/serum type formulation. No oil or sugar.

    I can’t use a chelator because I may have to add a zinc salt in one of the formulations so that won’t quite work with a chelator, I’m thinking.

    Package won’t be as invasive as a finger-in-cream type; it will be most likely a spoid-type dropper dispenser, which does have a chance of contamination form users.

    As for glycol I can increase it a bit in some formulations. Would, say 10% propanediol significantly help preservation instead of 5%?

    • Graillotion

      Member
      September 21, 2024 at 11:51 pm

      Keep the chelate for multiple reasons. Even MB’s making magnesium potions and lotions can and should use a chelate.

      A chelate has varying affinity’s… and generally they prefer iron over all others. As you are well aware, mold struggles in an environment completely devoid of iron ions.

      Yes…your chelate will become completely exhausted in your metal potion…but it will prioritize what metals it binds with first. This will also be enhanced with the order…..add you water portion and chelate…before you toss the other metals into the potion.

  • PhilGeis

    Member
    September 21, 2024 at 7:36 am

    meant the cap and pent glycols

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