# dissolving edta



## milky (Jul 9, 2017)

I'm hesitant to ask this because I think maybe I'm missing something obvious, but I'm trying to use tetrasodium edta for the first time and am having trouble dissolving it.
So far, I've measured 3.5 grams of edta and added 25g of distilled water. I've been stirring it once in a while for half a day, hoping for improvement and trying to find the answer online. 
Do I need to heat it?


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## earlene (Jul 9, 2017)

*Milky*, are you sure you have the correct type of EDTA?  See *DeeAnna*'s instructions here for more information about the right type, etc.

I have not had any trouble dissolving it in unheated distilled water, so I am not sure why it is not doing so for you.


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## Dahila (Jul 9, 2017)

tetrasodium Edta it is inci name, it happily dissolves in water.  I use 39% solution you will find a tread about it by Irishlass and then Deeanna 
http://www.soapmakingforum.com/showthread.php?t=52456
http://www.soapmakingforum.com/showthread.php?t=54669


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## Soapmaker145 (Jul 10, 2017)

milky said:


> I'm hesitant to ask this because I think maybe I'm missing something obvious, but I'm trying to use tetrasodium edta for the first time and am having trouble dissolving it.
> So far, I've measured 3.5 grams of edta and added 25g of distilled water. I've been stirring it once in a while for half a day, hoping for improvement and trying to find the answer online.
> Do I need to heat it?



If you got the acid form instead of one of the EDTA salts, you'll have to add NaOH to neutralize it to get it to dissolve.  You can use a pH paper to check the pH. If it is around 4 or 5, you have the acid form.  

Check your supplier to see what you actually bought.  The acid form is fine once you neutralize it.   It won't go into solution until the pH is raised above 7.  You can always make 0.5M stock solution around pH 8.0 and have it available for when you need it.


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## DeeAnna (Jul 10, 2017)

*DI*sodium EDTA is only slightly soluble in water and is suitable only for acidic products. *TETRA*sodium EDTA easily dissolves in water up to a 50% concentration and is required for alkaline products (soap). Given your troubles, Milky, I suspect you have DI, not TETRA. 

Since I wrote the posts that Dahlia shared about making 39% tetrasodium EDTA solution, I have learned that you can make a 50% solution instead. This makes the math easier and reduces the amount of extra water added that can affect the behavior of your soap recipe. Here's a link to the thread in which the 50% EDTA solution is discussed: http://www.soapmakingforum.com/showthread.php?t=62761  There is also a link in that thread to an article that I put on my website for easy reference.


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## Dahila (Jul 10, 2017)

DeeAnna I was planning to use 50 solution and forgot about it, I made a huge bottle of 39% well one day I am going with 50


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## milky (Jul 10, 2017)

This was the product I bought. It doesn't say anything about being a salt or an acid but unless it is terribly mislabeled, being the acid form is my guess. If that's the case, is there anything wrong with adding it directly to the lye solution? Or would it dissolve if I added enough water and slowly stirred in all the lye powder?

Edit: Would I need to adjust the amount of lye at all for the amount that neutralizes it? My guess is that it's super tiny so probably no..


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## bumbleklutz (Jul 10, 2017)

milky said:


> This was the product I bought. It doesn't say anything about being a salt or an acid but unless it is terribly mislabeled, being the acid form is my guess. If that's the case, is there anything wrong with adding it directly to the lye solution? Or would it dissolve if I slowly stirred in all the lye?



I wouldn't try to dissolve it in the lye water.  Although I've never had it happen, I understand that the edta powder can form a pudding-like mass in the lye water that makes it difficult to blend.  

As it happens, I have the exact same tetrasodium edta as you from the same supplier.  I haven't used it yet, as I have been using up the edta I got from a different supplier.  I'll try to dissolve some later and see if I can replicate the problem you're having.  If so, it may be a quality/labeling issue with that particular batch of edta from that supplier.  I'll post my results here later.


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## milky (Jul 10, 2017)

bumbleklutz said:


> I wouldn't try to dissolve it in the lye water.  Although I've never had it happen, I understand that the edta powder can form a pudding-like mass in the lye water that makes it difficult to blend.
> 
> As it happens, I have the exact same tetrasodium edta as you from the same supplier.  I haven't used it yet, as I have been using up the edta I got from a different supplier.  I'll try to dissolve some later and see if I can replicate the problem you're having.  If so, it may be a quality/labeling issue with that particular batch of edta from that supplier.  I'll post my results here later.



I hope we can get it to work! I remember reading that now, about turning to pudding. Guess I'll try to add a tiny bit of lye and see if it dissolves and if it does... then blend into oils and make the lye solution with the rest of the water? If it doesn't dissolve then I have a whole bunch of unusable something. :???: What would you do with it?


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## Dahila (Jul 10, 2017)

I add dissolved Edta to water , then sugar, then lye not the other way around. Some people add EDTA solution to oils, but i prefer add it to water.  Your Tetrasodium Edta seems to be ok.  When I make solution I add powder to slightly warm water , it mix in seconds but you need to wait a minute or two to clear it
I add edta to some of my lotions too it boost the preservation


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## Soapmaker145 (Jul 10, 2017)

milky said:


> This was the product I bought. It doesn't say anything about being a salt or an acid but unless it is terribly mislabeled, being the acid form is my guess. If that's the case, is there anything wrong with adding it directly to the lye solution? Or would it dissolve if I added enough water and slowly stirred in all the lye powder?
> 
> Edit: Would I need to adjust the amount of lye at all for the amount that neutralizes it? My guess is that it's super tiny so probably no..



The acid form takes a lot of NaOH to neutralize.  It will significantly raise the superfat.  Dissolve it separately to get it to the right pH (around 8 or 9 will be fine) and then add it to the lye.

The image on your link said tetrasodium EDTA.  If that is what they sent you, you shouldn't have had a problem dissolving it.  There is something very wrong with your chemical.  You need to contact your supplier and find out what they sent you.  My suggestion is not to use it until you know more.


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## Rusti (Jul 10, 2017)

The image and the webpage title that shows up in the browser tab both say 'tetrasodium' but the heading on the page itself says 'disodium', so there's some screw up here, somehow.


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## bumbleklutz (Jul 10, 2017)

bumbleklutz said:


> I wouldn't try to dissolve it in the lye water.  Although I've never had it happen, I understand that the edta powder can form a pudding-like mass in the lye water that makes it difficult to blend.
> 
> As it happens, I have the exact same tetrasodium edta as you from the same supplier.  I haven't used it yet, as I have been using up the edta I got from a different supplier.  I'll try to dissolve some later and see if I can replicate the problem you're having.  If so, it may be a quality/labeling issue with that particular batch of edta from that supplier.  I'll post my results here later.



Ok, so here are the results of my experiment.  You are correct.  The tetrasodium edta in question will NOT dissolve in distilled water. The label on the jar it came in is clearly marked tetrasodium edta.  First let me say that the texture of the edta powder is odd.  It is fluffy like corn starch.  The edta I have from lotioncrafters is more granular like salt. 

I tried dissolving 50 grams of the edta in 50 grams of distilled water.  I ended up with a  thick (about the consistency of heavy cream) white slurry similar to what you would get if you mixed corn starch or flour with water.  No amount of stirring would get the stuff to dissolve.  I attempted heating the mixture in the microwave and stirring more.  No luck.  I added additional water to the mix and heated again.  Still nothing. Nada. Not happening.

The tetrasodium edta from lotioncrafters dissolves easily in an equal amount of distilled water to form a clear solution.  This remained an opaque slurry no matter what I did to it.

I would NOT attempt to use this in soap.

At this point, I can't even begin to guess what this substance might be; but if it is tetrasodium edta, it's the weirdest I've run across in my somewhat limited experience.  Hopefully, DeeAnna will see this and chime in with some additional insight.  

So to conclude, I have 2 pounds of something that is labeled tetrasodium edta, but certainly doesn't act like it.

I'm including some pictures of the experiment so you can see the results.


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## Arimara (Jul 10, 2017)

bumbleklutz said:


> Ok, so here are the results of my experiment.  You are correct.  The tetrasodium edta in question will NOT dissolve in distilled water. The label on the jar it came in is clearly marked tetrasodium edta.  First let me say that the texture of the edta powder is odd.  It is fluffy like corn starch.  The edta I have from lotioncrafters is more granular like salt.
> 
> I tried dissolving 50 grams of the edta in 50 grams of distilled water.  I ended up with a  thick (about the consistency of heavy cream) white slurry similar to what you would get if you mixed corn starch or flour with water.  No amount of stirring would get the stuff to dissolve.  I attempted heating the mixture in the microwave and stirring more.  No luck.  I added additional water to the mix and heated again.  Still nothing. Nada. Not happening.
> 
> ...



I had a similar issue with the Tetra EDTA that I have. I haven't used it since.


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## bumbleklutz (Jul 10, 2017)

Arimara said:


> I had a similar issue with the Tetra EDTA that I have. I haven't used it since.



Arimara, did it happen to come from soapgoods.com?  The reason I ask is that both mine and milky's came from there.  I'm thinking it's not tetrasodium edta at all and is something else entirely that was mislabeled as tetrasodium edta.


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## DeeAnna (Jul 10, 2017)

"...if it is tetrasodium edta, it's the weirdest I've run across in my somewhat limited experience. Hopefully, DeeAnna will see this and chime in with some additional insight...."

I'd love to have a great answer for you ... but I truly don't have a clue what this stuff is, Bumbleklutz. 

I get my tetra EDTA from lotioncrafter.com. It's a fine pure-white powder, but definitely not fluffy. More like a very, very fine-grained table salt. I don't know what di EDTA is like -- never used it.

When I dissolve it in room temperature distilled water, the EDTA can take a short time to dissolve, especially if I'm making a 50% solution, but it forms a water-clear liquid quite easily within a minute or two. I never see this milky gritty mixture like you show in your photos.


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## Arimara (Jul 10, 2017)

bumbleklutz said:


> Arimara, did it happen to come from soapgoods.com?  The reason I ask is that both mine and milky's came from there.  I'm thinking it's not tetrasodium edta at all and is something else entirely that was mislabeled as tetrasodium edta.



Yep, that's where I got it from. I think I'm going to look into chucking this crap out. It's been a while since I bought it.


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## DeeAnna (Jul 10, 2017)

Hate to say this, but maybe the supplier is selling this as discontinued item with no return and no refund for a reason other than "it's not selling well"?


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## bumbleklutz (Jul 10, 2017)

Arimara said:


> Yep, that's where I got it from. I think I'm going to look into chucking this crap out. It's been a while since I bought it.



Same here Arimara...into the trash it goes.   

Thanks for the insight DeeAnna.  My lotioncrafter's tetra edta has always appeared and behaved exactly as you say. 

I hate to say it DeeAnna, but I think you're right.  I agree there's a reason that it's on clearance at such a low price other than slow sales.


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## Soapmaker145 (Jul 10, 2017)

Somebody needs to take the pH of this slurry.  pH paper is fine.  You just need to know which neighborhood you're in (around 5 or around 10).  Slurry is what you get when you use the acid form of EDTA.  It is what I use most of the time.  If the slurry is acidic and assuming an honest mistake by the supplier, it is likely the acid version of this chemical.  The acid form won't go into solution no matter what you do until you raise the pH.  The di and tetra EDTA are nothing more than the acid form that was already treated with NaOH for convenience.

Before you dump it (not readily biodegradable chemical), do a pH check and contact the supplier.

ETA: Don't heat the solution.  It will generate enough heat on its own when you add NaOH to the EDTA slurry.


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## milky (Jul 10, 2017)

Rusti said:


> The image and the webpage title that shows up in the browser tab both say 'tetrasodium' but the heading on the page itself says 'disodium', so there's some screw up here, somehow.



They changed the title and replied to my email asking about it. Here's what they said:
"We appreciate your business and interest in our products! It looks like you are correct, we have an error on this product type / name, its Disodium EDTA not Tetrasodium EDTA.  I apologize for this error and if you would like to return we will send you out a prepaid return label for a full refund. "

So.. now we know. Big mistake on their part but good customer service so far. I'll see how returning goes.


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## milky (Jul 10, 2017)

Soapmaker145 said:


> The di and tetra EDTA are nothing more than the acid form that was already treated with NaOH for convenience.



Can di EDTA be turned into tetra? It's probably not something I'll want to bother with but if it saves me from having to buy more elsewhere then maybe..

Edit: Ah, I see what you meant now. Upon looking it up, it appears that tetra and di EDTA are interchangeable so long as you account for the pH and buffer as needed. Is there a way to get the pH right without strips or an acid meter? What about making a balanced equation and weighing it out?


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## Soapmaker145 (Jul 11, 2017)

milky said:


> Can di EDTA be turned into tetra? It's probably not something I'll want to bother with but if it saves me from having to buy more elsewhere then maybe..
> 
> Edit: Ah, I see what you meant now. Upon looking it up, it appears that tetra and di EDTA are interchangeable so long as you account for the pH and buffer as needed. Is there a way to get the pH right without strips or an acid meter? What about making a balanced equation and weighing it out?



You got it.  If you add enough NaOH to the di EDTA, you end up with the tetra.  You can even add KOH.  It isn't any different than neutralizing citric acid or vinegar with NaOH before adding it to the rest of the soaping lye.

You can get the pH right if you add NaOH slowly and allow the EDTA to dissolve.  Add 0.5 g of NaOH to your solution and stir to dissolve for few minutes.  If it doesn't clear, add 0.5g to 1g at a time until it's all dissolved. If what you have is EDTA, it'll go in solution without any problems.  pH paper is very convenient to check the pH.  It takes the guesswork out.  

The disodium salt shouldn't need much NaOH to dissolve.  I'll check what forms of EDTA I have in stock tomorrow.  I'll be able to tell you exactly how much NaOH you need to add if I have the right form.


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## cmzaha (Jul 11, 2017)

DeeAnna said:


> Hate to say this, but maybe the supplier is selling this as discontinued item with no return and no refund for a reason other than "it's not selling well"?


It actually does state that clearance items Can be returned in 10 days


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## DeeAnna (Jul 11, 2017)

I stand corrected. Thanks, Carolyn!


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## Soapmaker145 (Jul 11, 2017)

If you decide to do this, do it on a small scale in a well ventilated space and wear protection particularly for the face just in case what you have is not EDTA.

I don't have disodium EDTA but I have the acid form.  I measured 23 g of the acid EDTA (fine powder) and added 50g of water and got the same slurry that is in the pictures.  I added 10 g of NaOH while stirring.  It heated up instantly and everything was dissolved in under a minute.  The solution cleared completely.  The pH at that point was between 7 and 8.  I added another 1.5g of NaOH to take the pH to about 9.  If it takes ~50% as much NaOH as EDTA to dissolve the EDTA form you have, it's the acid form.  If you get a clear solution with significantly less NaOH, you have the disodium salt.  The EDTA acid I'm using is >99% pure.  The purity of the chemical you have may vary but should be above 95%.

I shouldn't have added the NaOH all at once because the solution overheated and wanted to boil.  If you try it, add the NaOH in 3 to 4 installment to avoid overheating.  This way, if you have the disodium form, you'll be able to figure it out because the chemical will not need as much NaOH to dissolve.

The last thing to consider is to reduce the amount of the acid EDTA used in the soap since gram for gram, there is more EDTA in the acid form than there is in the tetra form.

If you don't trust the supplier, you can always trash it or return it.


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