What is the difference between a surfactant, emollient, humectant, stabilizer, or emulsifier?
Each of these terms serves the skin differently as well as the formula.
How to know one mixture from another
Surfactant
A substance that reduces the surface tension in order to allow the liquid to spread easily. The surfactant helps to lift dirt and oil from the skin. They help disperse ingredients evenly in a formula and on the skin surface. There are anionic, cationic, and nonionic which all serve differently.
Emollient
A substance that moisturizes, soothes, and softens the skin.
Humectant
A substance that helps keep the skin moisturized by attracting and retaining moisture in the product into or beneath the surface of the skin.
Stabilizer
A substance that maintains the physical and chemical quality of a product. The stabilizer helps prevent the texture, appearance, and separation over time.
Emulsifier
An emulsifier helps ingredients that are not easily mixed combine. The emulsifier helps stabilize an emulsion where one liquid is dispersed in the other as tiny droplets.
Effects on skin
Surfactants cleanse. Emollients soften. Humectants attract and deliver moisture. Stabilizers give the skin effective ingredients. Emulsifiers deliver the right concentration of ingredients.
Effects on formula
Surfactants help mix ingredients that need a lower surface tension and dissolve solutes. Emollients can thicken the formula. Humectants can serve as solutes. Stabilizers prevent ingredients from degrading. Emulsifiers combine ingredients and hold them in the combined state.
Other Considerations
- The pH of a product will effect how each ingredients treats the skin and behaves in the formula.
- Buffers can used to keep the pH ideal for skin and the ingredients in the formula.