Fragrance is a mixture of chemicals that give a product a distinctive smell. It can come from natural sources like flowers, pine trees and food or from synthetically manufactured fragrances commonly found in scented household products. Regardless of origin, over 5000 different fragrance chemicals are used in a wide variety of products. Fragrance is a common ingredient in perfume, cologne, aftershave and deodorant. In fact, a single bottle of perfume may contain tens to hundreds of individual fragrance ingredients that are simply listed by the generic term “fragrance.” Many of these fragrance chemicals are known to be skin allergens that can cause rashes and other unpleasant reactions.
Perfume is the most commonly used form of fragrance and is applied to the skin for a pleasant odour. Perfume can be classified into 5 main groups loosely based on their concentration of aromatic compounds. Parfum, or extrait, has the highest concentration of fragrance and is the most expensive. Other scents such as eau de toilette or cologne, eau de parfum, and eau de concentree have lower concentrations of perfume oils. The lower concentrations of oil in the perfumes are often referred to by terms such as extreme, intense, or concentrated, however, the perfume oils that make up these different scents are not necessarily the same. For example, the perfume oil that makes up Chanel No. 5 in its parfum, EdP, and the discontinued EdC concentrations are actually different perfume oil mixtures.
The top notes are the light, short-lasting scents that come from citruses and other fruit, spices, herbs, or florals. Middle notes have a deeper, more complex and rounded aroma. They include the heart of a perfume and provide the lasting impression of the scent. These are typically made from more potent natural fragrance materials such as rose, jasmine, ylang ylang, lily of the valley and geranium. The base notes add richness, depth, and balance to the perfume and are comprised of large molecules that last 2-4 hours after application. They can include woody notes such as patchouli and oakmoss or aquatic or marine notes, such as calone or muguet.
Traditionally, some of the odour ingredients in perfume were obtained from animals such as whales and the civet cat. These are now replaced with plant extracts and synthetic ingredients that duplicate the scent of these natural animal odours.
While some perfumes are made only from natural essential oils or tinctures, most modern fragrances contain a mix of both. The difference between natural and synthetic ingredients is that synthetics can be more readily available and can be formulated to achieve certain desired scents more economically than the rarer natural ingredients. For example, the ozonous marine notes of linalool and coumarin can be synthesized inexpensively from terpenes, while the fresh odour of orchids requires the expensive molecule called hexyl cinnamal.
The fragrance industry has maintained a rigorous system of safety assurance for more than 30 years. The International Fragrance Association (IFRA) and the Research Institute for Fragrance Materials maintain a systematic testing program that includes hazard identification, exposure assessment, skin sensitization, group health, respiratory, and environmental testing.