Wednesday, June 27, 2012

Question: How to use BTMS-25 in place of BTMS-50?

A few questions have come up around using BTMS-25 in a conditioner when you don't have access to BTMS-50, so let's take a look at what we could do here! (Click here for the post on substitutions, click for the post on emulsifiers!)

What's the difference between BTMS-25 and BTMS-50? 
BTMS-50 is behentrimonium methosulfate (and) cetyl alcohol (and) butylene glycol. It has 50% behentrimonium methosulfate, the active ingredient for conditioning our hair, the cationic quaternary compound. It contains cetyl alcohol to boost the substantivity of the conditioner, and butylene glycol as a humectant.

BTMS-25 is Behentrimonium Methosulfate (and) Cetearyl Alcohol. It has 25% behentrimonium methosulfate. It contains cetearyl alcohol to boost the substantivity of the conditioner. It does not contain a humectant.

A quick aside on how conditioning agents work...
The cationic quaternary compound is a positively charged compound - the behentrimonium methosulfate - that adsorbs to our hair strand to give us all those lovely conditioning qualities like a reduction in friction and combing forces, a reduction in static electricity, an increase in moisturization, and so on. Adsorption means the molecules accumulate on the surface of your hair. It's different than absorption in that it doesn't penetrate the hair fibre - it sits on top. We call this substantivity. A material that is positively charged will be attracted to the surface of our hair, which is negatively charged. The cationic quaternary compound is hydrophobic - "scared of water" - so it will resist removal by water alone. (The more hydrophobic the quaternary compound, the less likely it is to be removed by water alone.) So the positively charged cationic quaternary compound is attracted to your negatively charged hair fibre and clings on to the surface.

How to add the fatty alcohol?
We can add fatty alcohols like cetyl alcohol or cetearyl alcohol to a conditioner to increase the substantivity of the product. It's suggested to add it at 50% of the conditioner amount.

If you use 8% BTMS-50, you're getting 4% behentrimonium methosulfate in the conditioner, so you'd use 2% fatty alcohol. (Use the fatty alcohol at 1/4 the amount of the cationic compound.)

If you use 8% BTMS-25, you'd be getting 2% behentrimonium methosulfate in the product, so you'd add 1% fatty alcohol. (Use the fatty alcohol at 1/8th the amount of the cationic compound.)

But here's the thing - the conditioner already has a fatty alcohol in it, so is there a point to adding more? It depends upon your hair type. I have oily hair, and I find that adding more fatty alcohol leads to greasiness in a shorter period of time. My best friend has fine, normal hair and she finds it weighs her hair down. So adding the fatty alcohol is up to you.

How to use BTMS-25 in a conditioner recipe that calls for BTMS-50?
If your goal is to get the same amount of behentrimonium methosulfate in the product, then it seems logical to suggest that you would want to use double the amount of BTMS-25. A recipe that calls for 8% BTMS-50 would require 16% BTMS-25...but I think you'd end up with something with a balm consistency instead of a liquid conditioner, so I'm not totally comfortable recommending this. Instead, I recommend making the recipe how it is written, and seeing how you like it.

I did an experiment last year to see how much conditioner my hair really needed. You can see the results here and see my new recipe here. I encourage you to conduct the same experiment at home. It really opened my eyes as to how little I really need! And you'll see that I sometimes make recipes that total more than 100%

The short answer that in a conditioner, I recommend substituting BTMS-25 for BTMS-50 at equal amounts and see how you like it. I know this contradicts what I said in a previous post, but I've learned more about our ingredients in the last few years and I've heard from readers who have successfully made products with BTMS-25, so I feel more comfortable suggesting a straight 1:1 substitution. As for the amount of cetyl alcohol, you can reduce it by half or leave it the same. It's up to your hair type. This really is a situation in which you'll have to do some experimenting to see what works best for you!

I found this post from a while ago - BTMS-25 and products not emulsifying. Please share your thoughts!


Nedeia said...

let's not wait to add a humectant, glycerin or butylene glycol.

I actually wonder: how much extra humectant should I use if I sub 1:1 BTMS-50 : BTMS-25?

Nedeia said...

* let's not forget to add, not let's not WAIT to add :-))

Sorry, I was talking to someone and my head wasn't on my neck when I wrote this monstrosity!

Nancy Liedel said...

Oustanding post!!!!!!! I love it and wanted it. I didn't ask, but it was on my secret wish list.

Always.Looking.4.1.More said...

Hi Susan. Thanks for the VERY GOOD info!

I've seen quite a few people refer to behentrimonium methosulfate (BTMS) as behentrimonium chloride and still call the chloride solution BTMS. Why is that, aren't they two different solutions?

always, Always, ALWAYS, A-L-W-A-Y-S! :-D

Susan Barclay-Nichols said...

Sorry, for some reason I wrote behentrimonium chloride instead of behentrimonium methosulfate. I was thinking of another product! There isn't a huge difference between the two, but they are different enough that they should be called BTMS and BTC (or something like that). What I don't get is how Whole Foods is okay with BTC but not BTMS. That makes no sense!

Mychelle said...

What a great post! I've mentioned before I prefer the BTMS 25 to the 50 version. I think it's the added humectant my hair doesn't like. I usually sub at 1:1 because if I double it I end up with paste. But the post is even better! I'm working with Rita BTMS 225 right now and it creates very thick emulsions. Your conditioner experiment inspired me to create a diluted version of my usual formula, with less of everything. It's a much better consistency, not too thin but squeezable. I'm excited to try it out tomorrow.

Mychelle said...

My conditioner experiment was a success! I used half my usual amount of BTMS and lightened up on everything but my silicones ('cause I love them the way they are). My hair is soft, shiny, nicely conditioned and feels very light. I'm pleased. I think I'll get a little more time between washes, and that's always a good thing. Happy formulating!

aspotunderthesun said...
This comment has been removed by the author.
Susan Barclay-Nichols said...

Hi Laura. It should work, but I'm afraid I can't guarantee anything. They list it as being pure behentrimonium chloride with no extra fatty alcohols? Could you ask the supplier to confirm this as I've never seen this kind of thing before!

Jane Askin said...

Hi again,
I notice some melt Btms with the oils and then combine, others melt it in the water phase instead. Does it matter?