We’ve mixed oil and water. We’ve decoded classifications. We’ve looked at different functions, explored emulsion types and tackled the natural vs synthetic debate.
Now it’s time to bring it all together.
Because knowing the theory is useful – but eventually, you’re going to be standing in front of a list of ingredients asking:
Which one does what?
Welcome to the final part of Emulsifiers Explained.
Let’s take a closer look at some of the emulsifiers, co-emulsifiers and solubilisers available from BrightPack and where they can fit into a formulation.
Ceteareth-20
Primary emulsifier | Non-ionic | Oil-in-water
Ceteareth-20 is a primary non-ionic emulsifier used to create oil-in-water (O/W) emulsions.
It is generally compatible with a broad range of cosmetic oils and ingredients and can be used in products such as:
- Face creams
- Body lotions
- Moisturisers
- Hand creams
If you’ve followed the series from the beginning, you’ll recognise that Ceteareth-20 is doing one of the big jobs: helping bring the oil and water phases together to form the emulsion.
Cetearyl Alcohol
Co-emulsifier | Fatty alcohol | Thickener & stabiliser
Despite the word alcohol in its name, Cetearyl Alcohol plays a very different role from the alcohol you might immediately think of.
In an emulsification system, it can act as a co-emulsifier, helping to support stability while also contributing to viscosity and skin feel.
It can be used in:
- Creams
- Lotions
- Barrier creams
- Moisturisers
Remember: a co-emulsifier generally supports your primary emulsifier rather than automatically replacing it.
Cetyl Alcohol
Co-emulsifier | Stability & slip
Cetyl Alcohol is another co-emulsifier, but it can contribute different characteristics to the finished formulation.
It can help:
- Improve slip
- Improve stability
- Produce lighter creams
Typical applications include:
- Lotions
- Face creams
- Hair conditioners
- Moisturisers
This is a great example of why understanding an ingredient's function matters. Two ingredients may both be described as co-emulsifiers without necessarily producing exactly the same result.
Stearic Acid
Co-emulsifier | Thickener | Viscosity builder
If you’re looking at the body and firmness of a formulation, Stearic Acid is another ingredient worth understanding.
It can help build viscosity and improve the body and firmness of creams, while supporting emulsification when combined with other emulsifiers.
Common applications include:
- Creams
- Body butters
- Cleansing creams
- Shaving creams
Again, think of the formulation as a system rather than expecting one ingredient to do everything.
BTMS-25
Cationic conditioning emulsifier
Here’s where things move into haircare.
BTMS-25 is a cationic conditioning emulsifier with anti-static properties that can help detangle and soften the hair.
It is particularly suited to products such as:
- Hair conditioners
- Hair masks
- Leave-in conditioners
- Beard conditioners
Remember our earlier discussion about classification? This is where understanding ionic charge becomes useful.
BTMS-25's cationic nature makes it particularly valuable in conditioning applications.
Polysorbate-20
Non-ionic solubiliser
Not every product needs to become a thick, creamy emulsion.
Sometimes you simply need to incorporate fragrance or essential oils into a water-based product.
Polysorbate-20 is a non-ionic liquid solubiliser that can help disperse fragrance and essential oils and, where the formulation and ingredients are compatible, help produce clear water-based products.
It can be used in:
- Toners
- Body mists
- Linen sprays
- Room sprays
- Facial mists
So if you're developing something like a mist rather than a lotion, you're dealing with a very different formulation challenge.
PEG-40 Hydrogenated Castor Oil
Non-ionic solubiliser
PEG-40 Hydrogenated Castor Oil is another non-ionic liquid solubiliser.
It can help solubilise fragrance and essential oils, improve clarity and reduce visible oil separation.
Applications can include:
- Body mists
- Perfume sprays
- Toners
- Micellar water
- Facial sprays
Polysorbate-20 and PEG-40 Hydrogenated Castor Oil may sound similar when you first encounter them, but ingredient selection should always be based on the requirements and compatibility of your complete formulation.
So, Which One Should You Choose?
After five parts, you probably know what we're going to say:
It depends on your formulation.
There isn't one emulsifier that's automatically the best choice for every product.
Ask yourself:
What am I making?
Cream, lotion, conditioner, mist or something else?
What role does the ingredient need to perform?
Primary emulsifier, co-emulsifier, thickener or solubiliser?
What finished texture and performance am I looking for?
What other ingredients does it need to work with?
And most importantly, remember that formulation is about the complete system.
An ingredient might be perfectly suited to one formula and unsuitable for another.
From Ingredient Names to Formulation Knowledge
When we started this series, an emulsifier may simply have been “the ingredient that keeps oil and water together.”
Five parts later, we hope you see there's a little more happening behind the scenes.
We’ve covered:
- What emulsifiers are and why they matter
- How emulsifiers can be classified
- Primary emulsifiers, co-emulsifiers and solubilisers
- Oil-in-water and water-in-oil emulsions
- Natural and synthetic options
- And finally, some of the emulsification ingredients available from BrightPack
You don’t need to become a cosmetic chemist overnight.
But if you’re developing products for your own small business, understanding why an ingredient is in your formulation and what job it is performing can help you make more informed decisions.
That’s what Emulsifiers Explained has been about.
The series was created with technical input from our in-house chemist to make formulation knowledge easier to understand, while BrightPack supplies the raw materials you need to put that knowledge into practice.
Because we don't only want to help you find ingredients.
We want to help you understand them.
That’s a Wrap on Emulsifiers Explained
Five parts. One very important ingredient category. And hopefully, emulsifiers now make a lot more sense than they did at the beginning.
Keep an eye on the BrightPack blog as we continue making the technical side of formulating a little easier to understand.