What is it? BTMS-25 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 25% of the active ingredient, Behentrimonium Methosulfate (compared to BTMS-50, which contains 50%). I find BTMS-25 makes thicker/firmer products than BTMS-50 due to the higher concentration of a hardening/thickening ingredient.
INCI Behentrimonium Methosulfate (and) Cetearyl Alcohol
Appearance Small white waxy beads
Usage rate 1–10% of the overall product; ~25% 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 it 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, and offers noticeable thickening.
Do you need it? If you want to make hair care products you’ll want a conditioning emulsifying wax—I tend to prefer BTMS-50 as it is more potent, but if you can’t get 50, 25 is a decent alternative. It is also wonderful as the emulsifier in lotions and as a conditioning add-in for body butters and balms!
Strengths Great conditioning skin and hair feel. Depending on where you live it may be easier to get than BTMS-50.
Weaknesses It’s more expensive than most non-cationic emulsifying waxes, and if you use a lot of it (more than 10%+) it can make your products smell a bit fishy.
Alternatives & Substitutions You’ll need to use something else that is both a complete emulsifying wax and conditioning/cationic. BTMS-50 is also a cationic emulsifying wax, but it contains twice the amount of active as BTMS-25, so you might want to consider using less. Behentrimonium Chloride (BTMC) can be a good alternative; pure BTMC does not contain any stabilizing ingredients so if a recipe calls for 5% BTMS-25 I would recommend using 1.25% BTMC and 3.75% cetearyl alcohol. The maxiumum recommended usage rate for BTMC is 3%.

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-25 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-25; the BTMS-25 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-25, and then using a non-cationic emulsifying wax. You will need to watch solubility and usage rates, though.

How to Work with It Melt in the heated oil phase.
Storage & Shelf Life Stored somewhere cool, dark, and dry, BTMS-25 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-25 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 it Buy it from an online DIY ingredient supplier. In Canada you can get it from Voyageur, in the USA you can get it from Lotion Crafter.

Some Formulations that Use BTMS-25


Posted on

February 22, 2019

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