Carrier oils (sometimes referred to as "fixed oils") are some of the most important ingredients used in cosmetics and soaps. Carrier oils are nonvolatile oils that are removed from the seeds and fruit of plants. These oils are used as emollients in lotions and creams and they are the primary ingredients used to make vegetable-based soaps. The term “fixed” refers to the fact that these oils do not evaporate when exposed to air. Carrier oils are also called triglycerides because they are composed of fatty acids and glycerides (glycerin). Fatty acids are not harmful to the skin, but, in fact, they are moisturizers and emollients. Several different fatty acids exist in fixed oils. They go by several names including stearic acid, oleic acid, linoleic acid, palmitic acid and lauric acid. Each carrier oil or fixed oil contains a unique combination of fatty acids which give that oil specific characteristics. For instance, oils that contain a high percentage of stearic acid or lauric acid are solid (saturated) at room temperature and are sometimes referred to as butters or fats. Vegetable oils that consist primarily of oleic acid are liquid (unsaturated) at room temperature.