What is the main ingredient in a water-in-oil emulsion?

A water-in-oil emulsion is characterized primarily by its higher oil phase content, which surrounds and encapsulates smaller droplets of water. In this type of emulsion, the oil acts as the continuous phase, meaning that oil is the predominant component that forms the base of the product. This base allows for the water droplets to be dispersed throughout the oil, creating a stable mixture that provides a rich texture and often enhanced moisturizing properties.

The dominant presence of oil is why this emulsion is commonly used in creamy lotions, certain types of makeup, and other cosmetic formulations where a hydrating effect is desired, alongside a protective barrier typically offered by oils. The other options—water, alcohol, and glycerin—are either ingredients that serve as solvents or active components but do not define the structure of a water-in-oil emulsion as effectively as oil does.