This category is for cosmetics raw materials. The principal raw materials used for manufacturing cosmetics are oily materials such as oils, fats, wax esters, and ester oils, and surface-active agents are used as emulsifiers, solubilizing agents, etc. Humectants, thickening agents, film formers as well as polymers are used as powders, ultraviolet absorbents, antioxidants, sequestering agents, coloring agents such as dyes and pigments, along with vitamins, pharmaceutical agents such as plant extracts and perfume.
Oil has the ability to dissolve fats and is widely used as a component of cosmetics. Oily materials control the evaporation of moisture from the skin and are used mainly to improve the feeling on use. The solute in a solution can be adsorbed to a gas–liquid, liquid–liquid, or liquid–solid surface. These remarkable changes in the properties of surfaces are called surface activity and the so-called surface-active agents are materials demonstrating unusual surface activity. This surface activity is exploited in emulsification, solubilization, permeation, wetting, dispersion, cleansing, etc.