Fragrance is a blend of chemicals that are added to perfumes, colognes, essential oils, scented lotions and other cosmetic products to give them their distinctive smell. It can also be found in household products such as detergents and cleaning sprays. Fragrance can be both natural (oils from plants and flowers) or synthetically manufactured, and the ingredients are often undisclosed on product labels when listed simply as “fragrance” or “parfum.” Some fragrance mixes have been associated with skin allergies and other health problems, including dermatitis, bronchitis and respiratory distress.
The word “fragrance” or “parfum” on a product label actually represents an undisclosed mixture of several dozen to over 200 scent chemicals that are mixed and diluted to form a particular smell. Most perfumes, colognes and scented products are made with synthetic fragrances rather than natural oils, because it is much cheaper to produce them this way. The chemically-produced fragrances can have a wide variety of odours, and many are designed to imitate more expensive natural oils.
Traditionally, perfumes were created with a combination of naturally-derived, plant and animal-derived and synthetic aromatic compounds. Raw materials were obtained either through steam distillation of flowers or leaves, by solvent extraction from plant or animal products, or by a process called enfleurage, in which petals are placed between layers of purified animal fat, which soaks up the flower oils. The resulting oil is then treated with alcohol to obtain a concrete substance, which can be refined and reworked to create perfumes.
Many modern perfumes are composed with a modular structure of different fragrance base components, rather than blending individual oils. Guerlain’s Aqua Allegoria line of perfumes, for example, is a good example of this approach. The base perfume is a pre-blended mixture of various scent chemicals, and formulated with a simple fragrance concept such as fresh cut grass or juicy sour apple.
The top notes are the first scents to emerge from a perfume, and they evaporate quickly. They are usually comprised of small light molecules such as citrus, berries or herbs. The middle notes are a bit more complex, and provide the heart of the perfume. These notes are a bit more potent than the head notes, and they help to mask any unpleasant initial impression from the base note.
Finally, the base note provides the body of the perfume and lasts for a longer period. This is generally a combination of large, heavy molecules that add depth to the overall fragrance. Common base notes include cedarwood, sandalwood, vanilla and amber [3,5].
The oil concentrations of perfumes vary widely. The terms parfum, EdP and EdT, as well as the now-discontinued EdC, are used to indicate the concentrations of the various aromatic components, but this can be misleading, as perfumes with the same name from the same perfume house may differ in their composition, even at the same dilution. The use of the term concentree, however, is more precise with regard to the oil concentration.