Listing ingredients when both KOH and NaOH is used

[candicec003]

I'm in the process of making a label for my shave soap. I use both types of lye, how do you list this in the ingredients without actually putting sodium hydroxide.... For example, Ive seen some people put sodium cocoate, and then a few ingredients down the list they have potassium cocoate…..how do they determine this? any input is appreciated

 

[shunt2011]

Depends on where you live and requirements. I list sodium hydroxide and potassium hydroxide.

 

[amd]

Short answer: Maths.

Longer answer: You have to calculate how much oil is used up by NaOH and how much is used by KOH. And then list in order. For example (for easy math) say you use 10 oz coconut oil, with 60% KOH and 40% NaOH, then you could assume that 6oz coconut oil would be saponified by KOH, and 4oz by NaOH. You would have to make the assumption that this applies to all oils - even though realistically, you don't know how much is being saponified by what.

And for that last reasoning, I would just list the hydroxides, because you'd just be working off assumptions. I'd also like to add that I'm not expert, this is how I would do it. Someone may have a more expert/scientific method.

 

[DeeAnna]

There are two methods of creating an ingredients list -- what goes into the pot and what comes out of the pot. Choose one or the other -- you can't mix the methods. The "-oate" ingredients are based on "what comes out of the pot" method.

The order of ingredients is from the largest amount by weight to the least by weight, and for the "what comes out of the pot" method, you will have to calculate the weights of the various ingredients being created by the saponification reaction, and then arrange them in order by weight. If you use the "what goes into the pot" method, it's a lot easier because you can work directly off your recipe.

Since you're in Canada, however, you should be investigating the labeling requirements for Canadian soap makers. I'm US based and I'm not sure what rules Canadian soap makers have to follow.

"...60% KOH and 40% NaOH, then you could assume that 6oz coconut oil would be saponified by KOH, and 4oz by NaOH..."

@amd -- Ugh, it's even more complicated than that. The 60% KOH and 40% NaOH in your example would be percentages based on the number of molecules of alkali, not on the weight of alkali, so your example isn't quite right.

 

[Andrew]

I am unfamiliar with Canadian labeling regulations. There is a shaving soap company called Tallow and Steel out of Winnipeg, Canada. You can follow Ryan's labeling example and know you're doing it right.

https://tallowandsteel.com/collections/all/products/boreal-shave-soap

 

[candicec003]

Short answer: Maths.

Longer answer: You have to calculate how much oil is used up by NaOH and how much is used by KOH. And then list in order. For example (for easy math) say you use 10 oz coconut oil, with 60% KOH and 40% NaOH, then you could assume that 6oz coconut oil would be saponified by KOH, and 4oz by NaOH. You would have to make the assumption that this applies to all oils - even though realistically, you don't know how much is being saponified by what.

And for that last reasoning, I would just list the hydroxides, because you'd just be working off assumptions. I'd also like to add that I'm not expert, this is how I would do it. Someone may have a more expert/scientific method.

Huh. Well then, i think i will list things before they go in the pot. With all my other products i list the ingredients as they come out of the pot, but this is different as i need to list both types of lye

 

[Lin19687]

You MUST go by Canada's Rules and Laws.
Look them up, I don't have a link for them, and make sure you are doing it by the law
I think, you can't go by what comes out of the pot, but what exactly goes in.