Tetrasodium EDTA

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Meganmischke

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I don't have hard water but my mother does. Can I add EDTA to my soap? I am guessing I will have to make a solution and do some math. Does anyone use it with good results? Suggestions on solution strength and % to add to soap? Thanks for your consideration.
 
I don't have hard water but my mother does. Can I add EDTA to my soap? I am guessing I will have to make a solution and do some math. Does anyone use it with good results? Suggestions on solution strength and % to add to soap? Thanks for your consideration.

I have hard water but have never added EDTA. I use coconut oil and a bit of castor in most of my recipes and sometimes a tad bit of sugar. Never had a problem with lather. I recently went to my sisters house and washed my hands with a bar of my soap she had out - the lather was crazy:shock: - when I asked her about her water I found out she has a water softener. I guess because I formulate for hard water I never thought about how it would behave in soft water.
 
The soap scum is the main concern. I don't worry too much about the lather as it will still clean with little lather. I have to clean her shower and even with spraying the shower with a vinegar solution after her showers it is a serious chore to clean. Thanks for the suggestions though.
 
Yes, you can use it, but I don't know what the usage rate is or how effective it is.

If you try it, let us know.
 
I did a forum search and it seems .5% of total batch wt including fo and additives using a 39% solution. There was one comment that suggested tetrasodium would not dissolve in ph under 8. But it also seems Irishlass uses it with success and doesn't mention prolems with dissolving. Guess I need to do more research.
 
I use tetrasodium EDTA in my batches (I have really hard water, too). I use it at .5% of the entire batch weight. By entire batch weight, I mean everything- oil, lye, water, FO, colorants, and any other additives I might use. And if I have some things that are too light to weigh (i.e., the weight of them is too light to register on the scale), I'll just count them as being 1 gram.

I make my own 39% solution out of the dry form (if you use less water than that, it doesn't dissolve properly), and then I do a couple of math calculations to make sure to add enough of the solution to equate to having .5% of the EDTA in my batch. It sounds complicated, but once you've done it a few times, it's as easy as buttoning your shirt. This is what I do:

First, I make up a bottle of 39% EDTA solution to store on hand.

Then I tally up the weight of everything in my batch in grams. It's very important that you use grams to tally your batch weight for this and not ounces, because the following calculations are based on using gram weights.

Next, I take that total gram weight and multiply it by .5% and jot the sum down on paper.

Then I take that sum and multiply it by 2.56 (I can give you the reasoning behind this specific figure later if you want, but for now, all that is necessary is to multiply the gram sum by 2.56). The resulting sum you get from that will be how much of the 39% solution in grams you will need to weigh out for your batch.

Besides helping soap to lather in hard water, tetrasodium EDTA also helps to prevent DOS, and it acts as a preservative booster in lotions and liquid soaps. It's not a preservative per se, but its ability to starve bacteria of their food helps your chosen preservative to do it's job better.


IrishLass :)
 
Omg Irishlass I was searching for info on tetra EDTA last night when I couldn't sleep ripping my hair out. TY!
 
Thanks for all that. So as long as the the solution strength is no higher than 39% there is no issues with dissolving?
 
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