Fragrance is a mixture of organic compounds that produces a distinct smell or odour, most often used in cosmetic products like perfume and cologne. These fragrances may be derived from natural substances such as flowers and spices, or they can contain synthetic ingredients created in laboratories. While the term fragrance suggests that the chemicals in a perfume have pleasant or pleasing properties, the word can also be used to describe any aroma that is enjoyable, including coffee and flowers. A perfume that contains the scent of a flower or an aromatic fruit is referred to as a fruity fragrance, while a perfume that is based on a strong or pungent substance is described as leathery, musky or heavy [1].
Perfume is made up of three structural parts – head, middle and base notes – to give the impression that the scent lasts longer after application. The top notes, which are usually the lightest in structure, give the initial impression on a person’s skin and evaporate quickly. They are often composed of a combination of essential oils and extracts, and may include citrus (lemon or orange), light fruits, or herbs such as sage or lavender.
The middle or heart notes of a perfume are more long-lasting and add a stronger impression to the scent, often adding depth and character to it. The scent of the middle notes is often a combination of several essential oils and extracts, and may include lily of the valley, rose or jasmine.
The base notes are the heaviest part of the perfume and provide a lasting impression, and are commonly a combination of musk, woods, amber, vanilla or oakmoss. The perfume’s base is then diluted with a solvent, which can be a mixture of ethanol and water or a rectified spirit. The mixture is then left to mature, which can take anywhere from a month to a year in an environment without light or oxygen, which helps the perfume oil to bond with the alcohol, giving it a more lasting scent.
When the perfume is ready, it is bottled in its final form and labelled for sale. A label will usually list the concentration of perfume oil and the main components, with the terms pour homme (for men) or pour femme (for women) to denote the fragrance for that gender. Some brands will produce multiple versions of the same fragrance, with different dilutions of the perfume oil. The different concentrations use slightly different combinations of perfume oils, and the differences in the odour can be easily detected by those who wear them.
The International Fragrance Association and the Research Institute for Fragrance Materials set the standards for the chemicals used in perfume, and manufacturers are responsible for ensuring that their fragrances do not cause harm to users. While some of the chemicals are linked to irritant and allergic contact dermatitis, current laws do not require companies to disclose all of their ingredients, making it possible for fragrances to contain hidden toxicants.