Potassium Sorbate/Sodium benzoate and testing

AleAle Member
I live in Mexico and I haven't been able to find Ecocert approved preservatives other than phenoxyethanol which I don't want to use. I read that is possible to use potassium sorbate with sodium benzoate as preservative. So I was wondering if these together can make a good broad-spectrum preservative. I haven't been able to find a reliable source indicating the percentage needed for preserving the products. 

Right now I am making very simple lotions with few ingredients like this: https://www.humblebeeandme.com/vanilla-coco-body-lotion/

How can I calculate the percentage needed of potassium sorbate and sodium benzoate? Also, I am really afraid of bacteria and mold so, is it possible to test it in small incubators such as the one sold in LotionCrafter? https://lotioncrafter.com/collections/lab-testing/products/mytemp-mini-digital-incubator 

If you know another one that I can get please advise. I cannot afford right now to take a course so any advice will be greatly appreciated!

Comments

  • BelassiBelassi Member
    You're not looking very hard. You can buy KEM NAT here for instance. There's also Inolex whose products I like, but their MOQ is like, two tanker trucks or something like that.
    COSMAT are on 53 42 26 04, give them a call. They have all sorts, incl. glyoxilic acid, and another preservative, STABIL.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • Yes if you are doing a small project from home, yes you can buy the lotioncrafter test kit. You may also want to read some books on microbiology and cosmetics to give you an idea of how the testing works.
    Sodium Benzoate you can use about 3% or less, and Potassium Sorbate its about 0.5% max. Hope this helps.
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • EVchemEVchem Member
    I'm also going to mention that those preservatives are most effective at lower pH (I shoot for 5.5 or lower). If you don't have a way of reliably testing your product pH those may not be the best system for you because your products may not be at a range where potassium sorbate and sodium benzoate can function effectively
  • AleAle Member
    Belassi - Thanks! I really don't know much but what I read in the internet and there is too much information; so I was not looking at the right products. I will look into those you mentioned. Hopefully I can find a distributor to sell in small quantities. I haven't seen many companies in Mexico selling in small quantities these type of products as in other countries. 

    Dr Catherine Pratt - Thank you! I will try those percentages and see how it goes. And I'll check for a test kit in Mexico. As for the book, can you please recommend one that is easy to understand? 

    EVchem - Thanks! I will check in Amazon for a pH meter.
  • GuntherGunther Member
    Ale said:
    I live in Mexico and I haven't been able to find Ecocert approved preservatives other than phenoxyethanol which I don't want to use. I read that is possible to use potassium sorbate with sodium benzoate as preservative. So I was wondering if these together can make a good broad-spectrum preservative. I haven't been able to find a reliable source indicating the percentage needed for preserving the products. 

    Right now I am making very simple lotions with few ingredients like this: https://www.humblebeeandme.com/vanilla-coco-body-lotion/

    How can I calculate the percentage needed of potassium sorbate and sodium benzoate? Also, I am really afraid of bacteria and mold so, is it possible to test it in small incubators such as the one sold in LotionCrafter? https://lotioncrafter.com/collections/lab-testing/products/mytemp-mini-digital-incubator 

    If you know another one that I can get please advise. I cannot afford right now to take a course so any advice will be greatly appreciated!

    To make an informed decision please look up Minuimum Inhibitory Concentrations for Sodium benzoate, Potassium sorbate and their combo.

    and you'll see that:

    1. These preservatives work much better at lower pH levels.

    2. Sodium benzoate needs high concentrations to inhibit certain bacteria.
    i.e. 10 mg/ml (1%) needed to inhibit Staphylococcus aureus
    http://agrojournal.org/15/04-05-09.pdf
    If you're using less than that percentage, you're virtually guaranteed to fail the microbiological challenge test (at the same pH)

    3. Na-benzoate + K-sorbate works better in combo, and lesser amounts are needed.
  • I would really avoid formulas that describe quantities as "4 drops vanilla 10-fold essential oil and 2 “blobs” benzoin essential oil".

    Also, making a stable product is not about the preservatives only. You need to make sure you use deionised water, add EDTA, add antioxidants, avoid using oils that are too high in iodine value (which is actually ok for this formula), use an emulsification system appropriate for the formula, avoid difficult to preserve ingredients and many other things.  


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