What is BTMS-50? BTMS-50 is a cationic (positively charged) emulsifying wax. Because it’s cationic it is also “conditioning”—it adsorbs (creates a very fine coating) on skin and hair, giving an amazing finish that is unique to cationic ingredients. It contains 50% of the active ingredients, Behentrimonium Methosulfate.

Trade names you may encounter include:

  • SPI-BTMS-50
  • Incroquat™ Behenyl TMS-50
  • BTMS 7550KC

In my experience the bane “BTMS-50” is the most common, but as always, check the INCI to know what you’re buying.

INCI Behentrimonium Methosulfate (and) Cetyl Alcohol (and) Butylene Glycol

It is approximately 45–55% behentrimonium methosulfate, 35-45% cetyl alcohol, and 5–10% butylene glycol (source).

Appearance Small white waxy beads
Usage rate 1–15% of the overall product; ~20–25% of of the oil phase to emulsify.
Scent Can be a bit fishy, but this usually doesn’t come through in finished products if used below 10–15%.
Approximate Melting Point 60°C (140°F)
pH 5–7 (2% solution)
Charge Cationic (positive)
Solubility Oil
Why do we use BTMS-50 in formulations? It gives our products the most luxurious, wonderful skin feel and leaves hair feeling stunning—easy to comb through and all kinds of silky. It also functions as a complete emulsifying wax.
Do you need BTMS-50? If you want to make hair care products, definitely yes. It is also wonderful as the emulsifier in lotions and as a conditioning add-in for body butters and balms!
Strengths Absolutely unbeatable conditioning skin and hair feel. I also find it’s typically one of the easier to acquire conditioning emulsifying waxes.
Weaknesses It’s more expensive than most non-cationic emulsifying waxes, and if you use a lot of it (more than 10–15%) it can make your products smell a bit fishy.
Alternatives & Substitutions for BTMS-50 You’ll need to use something else that is both a complete emulsifying wax and conditioning/cationic. BTMS-25 is also a cationic emulsifying wax, but it contains half the amount of the active ingredient (behentrimonium methosulfate) as BTMS-50, so end products made with BTMS-25 will be less conditioning than products made with BTMS-50. Products made with BTMS-25 also tend to be thicker than BTMS-50 as 25 contains more fatty thickener than 50, so if the formulation you’re looking at contains BTMS-50 and a thickener like cetearyl alcohol or cetyl alcohol, I’d try replacing both the BTMS-50 and the fatty thickener with BTMS-25; that way you’ll get more behentrimonium methosulfate to help make up for the loss, and the product might not be noticeably extra thick.

Behentrimonium Chloride (BTMC) can be a good alternative. BTMC is sold in a variety of different formats, so check to see how concentrated yours is, and if it is blended with any thickeners. My BTMC from Making Cosmetics is more concentrated than BTMS-50 and does not contain any stabilizing ingredients, so if a formulation called for 5% BTMS-50 I would recommend using 2.5% each BTMC and cetearyl alcohol.

You can also look at alternatives like Varisoft® EQ 65 and Emulsense HC, but be sure to familiarize yourself with the formulation requirements for those options as they can have quite narrow effective pH ranges and other requirements. I also find they are not as potent as BTMS.

Non-cationic emulsifying waxes (Polawax, Emulsifying Wax NF, Olivem 1000, Ritamulse, etc.) are not good alternatives for BTMS-50 as they are not going to bring that conditioning element to your formulation. They’ll emulsify the product, but that’s it. This is likely not going to ruin the product, but it will definitely negatively impact the performance. If it’s a hair conditioner you will definitely notice a decline in detangling and the silkiness of the hair. If it’s a conditioning body butter, there’s really no reason to use something Polawax in place of the BTMS-50; the BTMS-50 was included primarily for the conditioning element, not the emulsifying element, so using a non-cationic emulsifying wax in its place is somewhat useless. In an anhydrous application I’d probably try replacing BTMS with 50% cetyl or cetearyl alcohol and 50% soft or liquid oil (more of whatever is in the recipe). That will likely require some tweaking for proper consistency, though. You would likely be better off looking for a body butter recipe that doesn’t use BTMS.

You could try incorporating a different cationic ingredient like a polyquaternarium into your formulation to replace the conditioning part of the BTMS-50, and then using a non-cationic emulsifying wax. You will need to watch solubility and usage rates, though.

How to Work with BTMS-50 Melt in the heated oil phase. It must be melted to work with it, but it can be stubborn about melting. I like to speed things up by quickly blitzing my BTMS-50 in my DIY-only coffee grinder to make it smaller.
Storage & Shelf Life Stored somewhere cool, dark, and dry, BTMS-50 is very shelf stable. I’ve had some for upwards of three years that hasn’t changed at all.
Tips, Tricks, and Quirks I find BTMS-50 can be a bit stubborn about melting in a water bath, so you might need to give your heated oil phase a quick burst in the microwave to get it to melt fully.
Recommended starter amount  100g (3.3oz)
Where to Buy BTMS-50 Buy BTMS-50 from an online DIY ingredient supplier. In Canada you can get it from Windy Point, in the USA you can get it from Lotion Crafter.

Some Formulations that Use BTMS-50


Posted on

November 19, 2018