Perfume is a liquid mixture of essential oils and other chemicals that combines to create a distinctive smell. It is usually sprayed onto the skin. The scent left behind is called sillage. It is often paired with a matching body lotion or shower gel. Perfume is a personal choice, and people have their own preferences for what scents they like. Some perfumes are designed to have three parts: the top notes (the first smells the nose notices), middle notes, and base notes. The scent of a perfume can last from two minutes to one hour after it has been applied. The chemicals used in perfumes are generally safe, but they can cause a reaction in some individuals. The perfumes may contain allergens, such as coumarin and eugenol. They also can irritate the skin and cause contact dermatitis.
The fragrance industry is regulated by the Food and Drug Administration and by state licensing agencies. A perfumer who manufactures a new perfume must apply for a permit to do so. The license is reviewed and approved by the agency, and the perfumer must meet certain safety requirements. The perfumer must have a minimum of five years experience in the fragrance industry and have passed a written exam. The perfumer is also required to submit a sample of the perfume to be tested for toxicity, and must pass a physical examination. The results of these tests must be submitted to the state.
Modern perfumes contain from ten to hundreds of ingredients. These include (1) natural aromatic plant extracts that provide the primary scents; (2) diluents and fixatives, which smooth transitions of a perfume’s different “layers” and enhance its stability; and (3) a solvent solution, typically an alcohol such as ethanol. The perfumer’s goal is to produce a fragrance that evokes a specific memory or feeling and that will appeal to the target audience.
Plants are the largest source of perfume aromatics. These are secondary metabolites that plants produce as protection against herbivores and to attract pollinators. Different parts of a plant can offer different aroma compounds, so the perfumer must choose carefully from several sources of a given scent. For example, the flowers of several species of rose and jasmine produce a wide variety of scents, as do the leaves and seeds of coriander.
In addition to their aromas, many of these aromatics are known to have other properties that affect human behavior and the body’s chemistry. For example, some are antidepressants and analgesics, while others have sedative effects. In addition, the context in which a perfume is presented can influence its connotation and denotation. For example, a scent that is associated with romance or sex can elicit sexual connotations, while the smell of an ice cream shop might suggest homeliness and comfort.
The earliest perfumes were created from a wide variety of natural ingredients, some of which are now considered gross by modern standards. For example, the perfumers of the ancient Etruscans sprayed themselves with a scented oil from the musk deer gland and hyraceum, a substance derived from petrified Hyrax feces. Modern perfumery began in the 19th century with the commercial synthesis of perfume chemicals such as vanillin and coumarin. These allow for the creation of scents that would have been impossible with natural aromatics alone.