Potassium sorbate as preservative

Hello. I am making a hair moisturizer and using potassium sorbate as a preservative and I have it in its powder form. I want to know how I dilute it. The package says it must be used in a 0.15-0.3% conentration. And I have it as 1% of my formulation.

Comments

  • A sneak peak at your new world.

  • May I ask where you got the information...that Potassium sorbate is a stand alone preservative?

  • Also you did not list pH.  You can not have a conversation about preservation without the pH being listed.

  • Okay, thank you. What preservatives do you suggest I use in combination with potassium sorbate?
  • PharmaPharma Member, Pharmacist
    Nicky said:
    Okay, thank you. What preservatives do you suggest I use in combination with potassium sorbate?
    Depends of the ingredients. The traditional (old) partner for sorbate is benzoate. Still commonly used for foods and less susceptible cosmetics. A better combo would be with phenoxyethanol.
    Sorbate shouldn't be used above 0.2% (which is the legal limit in several countries) due to adverse skin reactions at higher levels.
    When using acids/salts such as sorbate or benzoate as preservatives, keep your pH as low as possible (<5ish).
    Usage: Add the required amount of potassium sorbate to water. It's a water soluble salt, it will dissolve easily.
  • Bill_TogeBill_Toge Member, Professional Chemist
    it's also very prone to oxidation in water-based formulas, and turns them brown over time - I've only ever used it for preserving hygroscopic powders
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • Hello! I buy ready to use preservative mix (sodium benzoate & potassium sorbate) on naturallythinking.com. I would like to make the mix by myself. Can you please suggest right percentage of water/benzoate/sorbate ?
    Thank you!
  • PhilGeisPhilGeis Member, Professional formulator
    Eugene said:
    Hello! I buy ready to use preservative mix (sodium benzoate & potassium sorbate) on naturallythinking.com. I would like to make the mix by myself. Can you please suggest right percentage of water/benzoate/sorbate ?
    Thank you!
    If that's all (and two organic acids - neither of which is likely natural) is  prob unnecessary duplication.  In any case, it's a very poor system.  Suggest ~3000 ppm of either with pH adjusted appropriately and something to impact Gram neg bacteria.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Eugene:

    If you ask for the compositional analysis perhaps you can get exact percentages, but typical usage rates are 0.3% Sodium Benzoate + 0.15% Potassium Sorbate, each of which you can add as powders directly to the water phase of your formula ... no need to make a separate blend in water unless you want to.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • You didn't say what is your pH.
  • @Eugene:

    If you ask for the compositional analysis perhaps you can get exact percentages, but typical usage rates are 0.3% Sodium Benzoate + 0.15% Potassium Sorbate, each of which you can add as powders directly to the water phase of your formula ... no need to make a separate blend in water unless you want to.
    Oh right! It is between 5-5.4
  • Abdullah said:
    You didn't say what is your pH.
    Oh right! It is between 5-5.4

    PhilGeis said:
    Eugene said:
    Hello! I buy ready to use preservative mix (sodium benzoate & potassium sorbate) on naturallythinking.com. I would like to make the mix by myself. Can you please suggest right percentage of water/benzoate/sorbate ?
    Thank you!
    If that's all (and two organic acids - neither of which is likely natural) is  prob unnecessary duplication.  In any case, it's a very poor system.  Suggest ~3000 ppm of either with pH adjusted appropriately and something to impact Gram neg bacteria.
    I try formulate organic. So I'm constantly in search for "natural" broad spectrum preservatives. In facial formulations  use geogard ultra, in anhydrous - Geogard ETC. I dot't like using ETC in lotions because it changes final scent of product. May be it will be better to use Geogard Ultra instead of sodium benzoate & potassium sorbate? I also use Sodium Phytate in every hydrous formulation.
    Thank you!

    MarkBroussard said:
    @Eugene:

    If you ask for the compositional analysis perhaps you can get exact percentages, but typical usage rates are 0.3% Sodium Benzoate + 0.15% Potassium Sorbate, each of which you can add as powders directly to the water phase of your formula ... no need to make a separate blend in water unless you want to.
    Thank you very much! Do you think it is enough broad preservative for emultion formulation with ~5.3PH?
    Or may be Geogard Ultra is more powerful?
    Thank you!
  • Eugene said:
    Abdullah said:
    You didn't say what is your pH.
    Oh right! It is between 5-5.4

    PhilGeis said:
    Eugene said:
    Hello! I buy ready to use preservative mix (sodium benzoate & potassium sorbate) on naturallythinking.com. I would like to make the mix by myself. Can you please suggest right percentage of water/benzoate/sorbate ?
    Thank you!
    If that's all (and two organic acids - neither of which is likely natural) is  prob unnecessary duplication.  In any case, it's a very poor system.  Suggest ~3000 ppm of either with pH adjusted appropriately and something to impact Gram neg bacteria.
    I try formulate organic. So I'm constantly in search for "natural" broad spectrum preservatives. In facial formulations  use geogard ultra, in anhydrous - Geogard ETC. I dot't like using ETC in lotions because it changes final scent of product. May be it will be better to use Geogard Ultra instead of sodium benzoate & potassium sorbate? I also use Sodium Phytate in every hydrous formulation.
    Thank you!

    MarkBroussard said:
    @Eugene:

    If you ask for the compositional analysis perhaps you can get exact percentages, but typical usage rates are 0.3% Sodium Benzoate + 0.15% Potassium Sorbate, each of which you can add as powders directly to the water phase of your formula ... no need to make a separate blend in water unless you want to.
    Thank you very much! Do you think it is enough broad preservative for emultion formulation with ~5.3PH?
    Or may be Geogard Ultra is more powerful?
    Thank you!
    Both preservatives are pH dependent and both will not work good enough at pH 5.3.

    As a general rule, if your product pH is above PKa of an organic acid, don't use that organic acid as main preservative. They may work as helper preservative.

    Why don't you work at pH below 5?

    Also if your product is cationic organic acids may not be compatible with it. 
  • PhilGeisPhilGeis Member, Professional formulator
    "Natural" is as meaningless/false as many such claimed combinations are "broad spectrum".   Geogard ultra is prob on eof the worst.  Please forget it.

    Organic acid(s)/Benzyl alcohol/Chelator at your pH may work.  Benzyl should be 5000+ppm plus.    Run a PET and stability.
  • Abdullah said:
    Eugene said:
    Abdullah said:
    You didn't say what is your pH.
    Oh right! It is between 5-5.4

    PhilGeis said:
    Eugene said:
    Hello! I buy ready to use preservative mix (sodium benzoate & potassium sorbate) on naturallythinking.com. I would like to make the mix by myself. Can you please suggest right percentage of water/benzoate/sorbate ?
    Thank you!
    If that's all (and two organic acids - neither of which is likely natural) is  prob unnecessary duplication.  In any case, it's a very poor system.  Suggest ~3000 ppm of either with pH adjusted appropriately and something to impact Gram neg bacteria.
    I try formulate organic. So I'm constantly in search for "natural" broad spectrum preservatives. In facial formulations  use geogard ultra, in anhydrous - Geogard ETC. I dot't like using ETC in lotions because it changes final scent of product. May be it will be better to use Geogard Ultra instead of sodium benzoate & potassium sorbate? I also use Sodium Phytate in every hydrous formulation.
    Thank you!

    MarkBroussard said:
    @Eugene:

    If you ask for the compositional analysis perhaps you can get exact percentages, but typical usage rates are 0.3% Sodium Benzoate + 0.15% Potassium Sorbate, each of which you can add as powders directly to the water phase of your formula ... no need to make a separate blend in water unless you want to.
    Thank you very much! Do you think it is enough broad preservative for emultion formulation with ~5.3PH?
    Or may be Geogard Ultra is more powerful?
    Thank you!
    Both preservatives are pH dependent and both will not work good enough at pH 5.3.

    As a general rule, if your product pH is above PKa of an organic acid, don't use that organic acid as main preservative. They may work as helper preservative.

    Why don't you work at pH below 5?

    Also if your product is cationic organic acids may not be compatible with it. 
    I use ECOmulse as emulsifier, its recomended ph is 5-7.5 ...
    Naturallythinking.com, where I buy preservative mix, says that sorbate/benzoate has ph range 1- 5.5. After you say they work better on lower PH I made a research on other websites and also found this info.
    Do you think it is ok for facial or body cream to have PH lower then 5?
    What preservative do you suggest to use, that are approved for "green" products?

    Thank you!
  • PhilGeis said:
    "Natural" is as meaningless/false as many such claimed combinations are "broad spectrum".   Geogard ultra is prob on eof the worst.  Please forget it.

    Organic acid(s)/Benzyl alcohol/Chelator at your pH may work.  Benzyl should be 5000+ppm plus.    Run a PET and stability.
    Thank you very much.
    Benzyl alcohol has such a strong scent... It changes product scent a lot.
    I was using Preservative Eco, and it is very smelly ((
  • PhilGeisPhilGeis Member, Professional formulator
    You need something of reliable efficacy versus Gram negative bacteria.  Organic acids are not at any pH.
  • Eugene said:
    Abdullah said:
    Eugene said:
    Abdullah said:
    You didn't say what is your pH.
    Oh right! It is between 5-5.4

    PhilGeis said:
    Eugene said:
    Hello! I buy ready to use preservative mix (sodium benzoate & potassium sorbate) on naturallythinking.com. I would like to make the mix by myself. Can you please suggest right percentage of water/benzoate/sorbate ?
    Thank you!
    If that's all (and two organic acids - neither of which is likely natural) is  prob unnecessary duplication.  In any case, it's a very poor system.  Suggest ~3000 ppm of either with pH adjusted appropriately and something to impact Gram neg bacteria.
    I try formulate organic. So I'm constantly in search for "natural" broad spectrum preservatives. In facial formulations  use geogard ultra, in anhydrous - Geogard ETC. I dot't like using ETC in lotions because it changes final scent of product. May be it will be better to use Geogard Ultra instead of sodium benzoate & potassium sorbate? I also use Sodium Phytate in every hydrous formulation.
    Thank you!

    MarkBroussard said:
    @Eugene:

    If you ask for the compositional analysis perhaps you can get exact percentages, but typical usage rates are 0.3% Sodium Benzoate + 0.15% Potassium Sorbate, each of which you can add as powders directly to the water phase of your formula ... no need to make a separate blend in water unless you want to.
    Thank you very much! Do you think it is enough broad preservative for emultion formulation with ~5.3PH?
    Or may be Geogard Ultra is more powerful?
    Thank you!
    Both preservatives are pH dependent and both will not work good enough at pH 5.3.

    As a general rule, if your product pH is above PKa of an organic acid, don't use that organic acid as main preservative. They may work as helper preservative.

    Why don't you work at pH below 5?

    Also if your product is cationic organic acids may not be compatible with it. 
    I use ECOmulse as emulsifier, its recomended ph is 5-7.5 ...
    Naturallythinking.com, where I buy preservative mix, says that sorbate/benzoate has ph range 1- 5.5. After you say they work better on lower PH I made a research on other websites and also found this info.
     the sellers want to sell you whatever they are selling. They will never tell you don't buy what i am selling because it is not working.

    When they say sorbate and benzoate work at pH 1-5.5 they don't mean it function the same in this range and after that it will directly become inactive. 
    They mean up to pH 5.5 you can see some benefit from this preservative. Some benefit doesn't mean enough benefit. 

    For example if you add 0.5% sodium benzoate, at pH 4 it will function like 0.3% preservative but at pH 5.5 like 0.02% preservative. 
    Can 0.02% sodium benzoate preserve your product? Never but it will do a little bit if combined with another preservative. 
    Did your supplier say what can this preservative do at pH 5.5 or they just said it can work and didn't say how much?

    Do you think it is ok for facial or body cream to have PH lower then 5?
    I think it is necessary for facial and body cream to have pH lower than 5 because
    1. Skin pH is 4.7.

    2. Your skin will recover better from lower pH than higher pH. For example pH 4 is better than 5.5.

    3. At lower pH your product will be better preserved so less harm from contamination.

    4. At lower pH you will need less preservative compared to higher ph and as preservative is the worst ingredient  in your product (but better than microbes) less of that means better product for skin.

    What preservative do you suggest to use, that are approved for "green" products?

    I don't know what green products are but in general i will suggest Paraben+phenoxyethanol or DMDM hydantoin. 





    Thank you!

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