Fragrance is the combination of chemicals that produce a distinct smell or odour. Perfume and cologne are the most well-known fragrance products, but the word can also be used to describe the scent of flowers or a plant or even an entire room. Using the word fragrant can also be ironic or humorous, as in These flowers are so fragrant that they’re making my whole house smell like perfume. The word is related to the verb fragrant, which means that something has a pleasant smell, as in These flowers are so fragrant that I can’t stand to be near them.
A fragrance is a mixture of different compounds natural and synthetic that are intentionally put together to create a specific smell. A scent is the smell that something gives off naturally, as in the natural aroma of a flower or the scent of a tree. Scents can be a very powerful memory trigger, and for this reason many people find it desirable to have their own signature fragrance.
Scent can be added to a variety of personal care products such as shampoos, shower gels and body lotions. Many of these contain perfume, although some people prefer unscented products to avoid the irritation that can be caused by some chemical ingredients found in fragrance. Fragrance is also used to make cleaning products such as detergents, fabric softeners and air fresheners.
Using a combination of essential oils and synthetic chemicals, the fragrance industry has developed a wide range of aromas for use in cosmetics. Perfume is traditionally categorized into five groups according to their concentration of aromatic compounds. The highest-concentration perfume is called parfum, or extrait, and is the most expensive. The lower-concentration perfumes are eau de toilette, eau de parfum extra and eau de cologne.
The modern fragrance industry began in the 19th century with the development of commercial synthesis of aroma compounds such as vanillin and coumarin. These allowed for the production of perfumes with scents that were previously unobtainable through natural materials. For example, linalool and coumarin can be produced inexpensively through the chemical modification of terpenes, which are naturally-occurring molecules in the volatile oil of certain plants.
In order to produce a high-quality fragrance, perfumers must carefully balance three sets of notes. These are the top note, the middle note and the base note. The top note is made up of small light molecules that give the perfume its initial impression and evaporate quickly, usually 5-30 minutes after application. The middle note adds a mellow, balanced and rounded feeling to the fragrance, and it is made up of more complex molecules that can last up to 2-4 hours. The base note provides a lasting impression and is composed of large heavy molecules that provide depth to the scent.
In addition to the raw materials that are used in perfume, the final product is regulated by the International Fragrance Association (IFRA) and the Research Institute for Fragrance Materials (RIFM). The IFRA and RIFM sets voluntary standards that manufacturers must meet when creating their fragrances. These standards include hazard identification, exposure assessment and dose-response testing to determine whether or not the fragrance is likely to cause an allergic reaction. The IFRA and RIFM also publish the Skin Deep database, which is designed to help consumers choose safer cosmetic products.