I got a great question on one of my last posts, Why oily skin needs an oil cleanser, asking:
So are emulsifiers acting like surfactants in the sense where their role is to wash off dirts and at the same time mix water and oil?
Quick answer: Yes. It gets a little more confusing when we add detergents in there, which are also a surfactant.
Confused? Let’s break it down.
What is a Surfactant?
Lets start with the easier term. A surfactant is anything that releases tension between two liquids (for skincare lets concentrate just on liquids). It stands for surface -active agent. Surfactants are used in all the industries: petroleum, agriculture, beauty, pharmaceuticals, manufacturing.
You’re probably asking yourself, what does a photo of a bunch of tadpoles have to do with any of this? Valid question, here it comes. Surfactants have a ‘Head’ and a ‘Tail’ much like a tadpole. In skincare, very often that head is hydrophilic (hydro- = water, -philic = loving). The tails are most often hydrophobic (hydro- =water, phobic = aversion).
The photo on the left is of Lancome’s Energie de Vie (discontinued) has one of the best visuals of oils suspension in water looks like. It’s probably castor oil that’s suspended in water and alcohols. Water and alcohols are both water and thus will mix (remember like-dissolves like). Notice how the droplets lay flat. that’s the surfactant at work.
Now imagine dropping a piece of food with all those tadpoles. All those heads will swim towards the food and you’ll see a bunch of tails pointing away from the food. Surfactants act the same way and will form a little ball. The water-loving head will point towards the water and the water-aversion tails will point away from the water in 3D.
One thing to make completely clear: Surfactant is an umbrella term. There are several sub-classes. All surfactants have a water-loving head and a water-aversion tail. They all kind of resemble a tadpole.
What’s an Emulsifier?
An emulsifier is a type of surfactant that surrounds oil globules and keeps them as a stable globule in the water.
Naturally, oils are going to want to rise to the top once they are floating in water. The emulsifier helps to dissolve oils and push them into the water and once in the water they’ll keep them from rising to the top.
Emulsifiers are not detergents (cleanser).
What’s the Difference Between an Emulsifier and Detergent?
An emulsifier is a surfactant. A detergent is also a surfactant. An emulsifier is not a detergent.
Detergents work similar to an emulsifier. Detergents have that water-loving head and water-aversion tail like all surfactants have. For detergents, that water-aversion tail will bind to dirt and oils and such, surrounding the particle and then rinsing away with water. Detergents do tend to be more stripping and they don’t suspend those dirt and oil particles in the water. Detergents also have a harder time getting into pores. To really clean out pores you need an oil cleanser.
The biggest point in skincare is that detergents are going to be mostly water-based. Like dissolves like. So they don’t need an emulsifier to suspend the oil, it’s already suspended because it’s water based.
Why choose an oil cleanser over a water-based or forming cleanser?
Oil cleansers do an excellent job of getting into pores where water cleansers can sometimes fail. So that oil cleanser acts as that first pull of the deeper oils in the pores and heavier oils on the skins surface while being incredibly gentle to the skin and not over stripping the surface skin. Since we rinse with water, we need those emulsifiers to lift that oil cleanser with the dirt and extra oil trapped inside into the water so it’ll rinse away. For a deeper knowledge of How Double Cleansing works click here.
Without the emulsifier in the oil cleanser formulation the oil cleanser will just sit on the surface of the skin and be impossible to rinse off completely. Imagine washing your face with pure coconut oil and trying to rinse that off. The coconut oil would act as a barrier and the water would just roll off.
If you need to follow an oil based cleanser with a foaming or water cleanser or even a micelle water by all means go for it. Doing this process is called double cleansing (oil cleanse followed by a water cleanse) and has been made incredibly popular with the rise of Korean beauty.
Final Thoughts
Oil cleansers are great. I’ve posted a lot regarding oil cleansers including double cleansing, how oil cleansers work, and incorporating a double cleansing into a routine. Check out the previous posts that I’ve linked and leave a question below or just let me know where you’re from! This is really a hobby so it’s nice to see how far this hobby has reached.
-XOXO-
Andrea
