Home Cosmetic Science Talk Formulating Lowest effective usage rate for EDTA

  • Lowest effective usage rate for EDTA

    Posted by Cafe33 on December 5, 2021 at 7:45 pm

    What is the lowest effective input for disodium EDTA? I am using it in a formula where I would like to keep water input to a minimum, and so far I am trying 0.03-0.05 %, Can I go lower? 

    Is there an advantage to adding a little (more soluble) tetrasodium EDTA as well? I did not want to use the tetrasodium salt initially since I noticed that in larger inputs, it seems to raise pH. The pH of my formula is near neutral. 

    Thanks

    Abdullah replied 2 years, 5 months ago 4 Members · 5 Replies
  • 5 Replies
  • Graillotion

    Member
    December 5, 2021 at 8:43 pm

    Not my area of expertise….but I would assume at some point the answer will relate to how much you are trying to chelate….. Water quality…or other ingredients that might bring something to the table that needs to be chelated.  If you have a pristine ingredient list…I would assume less can be used…than an ingredient list that is bring a lot of chelation needs.

    Again…I am no expert…just seems like there might be some logic there.

  • ngarayeva001

    Member
    December 6, 2021 at 1:05 am

    Tetrasodium is supposed to be used in higher ph products. The trick with disodium is heating it.

  • Abdullah

    Member
    December 6, 2021 at 2:09 am

    What is your water percentage?

  • Cafe33

    Member
    December 6, 2021 at 3:32 pm

    It is challenging since I am trying to apply it to Syndet bars. I am attempting to scale my process and also acquire an extruder. 

    Previously I was not adding any free water. Currently, I am testing a water level of 0.3-0.5%, I prefer not to go higher. I do start by heating water with the EDTA. I then add NaCl followed by Sodium Lactate and CAPB. Those are the principal components of my water phase. 

    I have noticed that Dove bars use 2 forms of EDTA, the pH of my bars is similar to Dove’s

  • Abdullah

    Member
    December 7, 2021 at 4:11 pm

    What are you using EDTA for in syndet bar?

    How much CAPB are you using because it also has 70% water and too much iron.

    I you want to make hard water soft, 600ppm EDTA can make 1 kg water soft.

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