How are essential oils used to add fragrance to cosmetics, soaps, and detergents?

Essential oils are used in cosmetics, soaps, and detergents primarily as odorants to provide fragrance. These oils are highly volatile substances isolated from plants through various physical processes, most commonly steam distillation, though methods like solvent extraction and mechanical pressing are also employed depending on the plant source.1

Once isolated, these oils—which contain complex mixtures of terpenes and other aromatic compounds—are incorporated into products to impart specific scents. Because natural essential oils can be expensive and limited in supply, manufacturers often use synthetic components to extend these supplies or to create reconstituted oils. However, these synthetic blends may lack the nuance of natural oils, as they often miss the unidentified trace ingredients that contribute to a characteristic, natural fragrance.1