Michigan Esthetician State Board Practice Exam

Which ingredient is known for its ability to form emulsions in skin care products?

1. Fatty acids

2. Humectants

3. Surfactants

4. Antioxidants

The correct answer is: Surfactants

The ingredient known for its ability to form emulsions in skin care products is surfactants. Emulsions are mixtures of water and oil that are stabilized by emulsifying agents. Surfactants play a crucial role in this process because they have both hydrophilic (water-attracting) and hydrophobic (oil-attracting) properties. This dual nature allows surfactants to reduce the surface tension between the water and oil phases, enabling them to mix and stay combined. Surfactants are commonly used in creams and lotions to create a stable product that maintains its texture and consistency over time. They can also assist in improving the spreadability of products on the skin, providing a smoother application experience. In contrast, while fatty acids can contribute to the texture and emollient properties of a product, they do not directly create emulsions. Humectants are designed to attract moisture to the skin but do not have emulsifying properties. Antioxidants protect the skin from damage and can enhance the stability of formulations, but they do not function to create emulsions. Thus, the role of surfactants in forming and stabilizing emulsions makes them the correct answer.