- For the book "Perfume" by Patrick Süskind, see Perfume (book).
Perfume is a mixture of fragrant essential oils and aroma compounds, a fixative, and alcohol used to give parts of the human body and sometimes other objects a long-lasting and pleasant smell.
The essential oils are obtained by distillation of flowers, plants, and grasses, such as orange blossom and roses. Extraction by enfleurage is used if distillation is not possible, for example in the case of Jasmin Absolute. Enfleurage is basically extraction by absorption of aroma materials into wax and then extracting the odorous oil with alcohol. Aromatic chemicals are also used. Fixatives, which bind the various fragrances together, include balsams, ambergris, and secretions from the scent glands of civets and musk deer (undiluted these have unpleasant smells but in alcoholic solution they act as preserving agents). The amount of alcohol added depends on whether perfumes, Eaux de toilette, or Eaux de Cologne are required. The mixture is normally aged for 1 year.
Perfumes types and properties
As the percentage of aromatic compounds decreases, the intensity and longevity of the scent decreases, also.
- Perfume extract: 20%-40% aromatic compounds
- Eau de parfum: 10-20% aromatic compounds
- Eau de toilette: 5-10% aromatic compounds
- Eau de cologne: 2-3% aromatic compounds
A mixture of alcohol and water are used as the solvent for the aromatics. On application, body heat causes the solvent to evaporate quickly, leaving the fragrance to evaporate gradually over several hours. The rate of evaporation(vapor pressure) and the odor strength of the compound partly determines the tenaciousness of the compound and determines it perfume note classification.
Top notes: Scents that are perceived a few minutes after the application of a perfume. Top notes create the scents that forms a person's initial impression of a perfume. Because of this, they are very important in the selling of a perfume. The scents of is note class are usually described as "fresh", "assertive" or "sharp". The compounds that contribute to top notes are strong in scent, very volatile, and evaporate quickly. Citrus and ginger scents are common top notes.
Heart notes or Middle notes : The scent of a perfume that emerges after the top notes wear-down. The heart note compounds form the "heart" or main body of a perfume and acts to smooth the sharpness from the initial impression of perfume that caused by the top notes. Not surprisingly, the scent of heart note compounds are usually more mellow and "rounded". Scents from this note class appear anywhere from 10 minutes to 1 hour after the application of a perfume. Lavender and rose scents are typical heart notes.
Base notes: The scent of a perfume that appears after the departure of the heart notes. Base Notes bring depth and solidness to a perfume. Compounds of this class are usually the fixatives used to hold and booster the strength of the lighter top and heart notes. The compounds of this class of scents are typically rich and "deep" and are usally not perceived until 30 minutes after the application of the perfume or during the period perfume dry-down . Musk, vetiver and scents of plant resins are commonly used as base notes.
History of perfume and perfumery
Perfumery, or the art of making perfumes began in ancient Egypt but was developed and further refined by the Romans and the Arabs. Knowledge of perfumery came to Europe as early as the 14th century. During the Renaissance period, perfumes were used primarily by royalty and the wealthy to mask bodily odors resulting from the sanitary practices of the day.
Partly due to this patronage, the western perfumery industry was created. By the 18th century, aromatic plants were being grown in the Grasse region of France to provide the growing perfume industry with raw materials. Even today, France remains the centre of the European perfume design and trade.
Natural and synthetic aromatics
Plants have long been used in perfumery as a source of essential oils and aroma compounds. These aromatics are usually secondary metabolites produced by plants as protection against herbivory as well as to attract pollinators. Plants are by far the largest source of fragrant compounds used in perfumery. The sources of the these compounds may be derived from various parts of a plant. A plant will often be more than one source of aromatics, for instance coriander aerial portions and seeds have remarkably different odors from each other. Orange leaves, blossoms, and fruit zest or the respective sources of petit grain , neroli oil, and orange oil.
Flowers: Undoubtably the largest source of aromatics. Includes the flowers of many species of roses and orchids, as well as jasmine, osmanthus , mimosa, and tuberose. Although not traditionally thought of as a flower, the unopened flower buds of the clove are also a commonly used flower. Orchids are not commercially used to produce essential oils or absolutes.
Leaves: Leaves commonly used for perfumery include patchouli, sage, violets, rosemary, and citrus leaves. Sometimes leaves are valued for the "green" smell it brings to perfumes, examples of this include hay and tomato leaf.
Roots, rhizomes and bulbs: Commonly used terrestrial portions in perfumery include iris rhizomes, vetiver roots, various rhizomes of the ginger family.
Seeds: Commonly used plant seeds include coriander, caraway, cocoa, tonka , nutmeg, mace, cardamom, and anise.
Fruits: Commonly used fruits include raspberry, strawberry, apple, citrus zests such as those of oranges, lemons, limes, and grapefruit. However, fruits do not always impart the expected "fruity" odors to perfumes. Notable exceptions include vanilla pods, star anise, pepper, allspice and durian.
Woods: Highly important in providing the base notes to a perfume, wood oils and distillates are indespensible in perfumery. Commonly used woods include birch, cedar, sandalwood, juniper, larch, and pine.
Bark: Commonly used bark includes cinnamon bark.
Resins: Valued since antiquity, resins have been widely used in incense and perfumery. Highly fragrant and antiseptic resins and resin-containing perfumes have been used by many cultures as medicines for a large variety of ailments. Commonly used resins in perfumery include labdanum, frankincense/olibanum, myrrh, Peru balsam , benzoin , agarwood, and various copals. Pine and fir resins are a particularly valued source of terpenes used in the organic synthesis of many other synthetic or naturally occurring aromatic compounds.
- Musk: Originally derived from the musk sacs from the Asian musk deer, it has now been replaced through the use of synthetic musks due to it price and various ethical issues.
Civet: Also call Civet Musk, this is obtained from the odorous sacs of the civets, animals in the family Viverridae, related to the Mongoose.
- Castoreum : Obtained from the odorous sacs of the North American beaver.
Ambergris: A fatty substance obtained from the Sperm Whale.
Honeycomb: As it name implies, honey or honeycomb aromatics are distilled from the honeycomb of the honey bee.
Synthetic aromatics are created through organic synthesis from various chemical compounds that are obtained from petroleum distillates or pine resins. Synthetics can provide fragrances which are not found in nature. For instance, Calone , a compound of synthetic origin, imparts a fresh ozonous metallic marine scent that is widely used in contemporary perfumes. Synthetic aromatics are often used as an alternate source of compounds that are not easily obtained from natural sources. For example, linalool and coumarin are both naturally occurring compounds that can be cheaply synthesized from terpenes. Orchid scents are usually not obtained directly from the plant itself but are instead synthetically created to match the fragrant compounds found in various orchids.
Health and ethical issues
Use of Aromatics
It is important to note that there is no benefit from creating a perfume exclusively from natural materials. There are several reasons for this:
- Many natural aroma materials are in fact inherently toxic and are either banned or restricted by IFRA. These naturals have been replaced by safer artificial or synthetic materials.
- In some cases, an excessive use of perfumes may cause allergic reactions of the skin (specifically, acetophenone is a well-known allergen present in many perfumes).
- No modern perfume will perform successfully without one or more musk aromas. Musk was traditionally taken from the male musk deer Moschus moschiferus. This required the slaughter of the animal and in practice, musk hunters did not discriminate between male and female, old and young. They killed them all, only to obtain the musk pod which was solely produced by the young male deer, and only when in season.
"Musk deer are protected under national legislation in many countries where they are found. The musk deer populations of Afghanistan, Bhutan, India, Nepal and Pakistan are included in Appendix I of CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora. This means that these musk deer and their derivatives are banned from international commercial trade." 
It is the policy of many perfume companies to use synthetic musk in place of natural musk for ethical reasons. Many synthetic musks are available and those used are all approved safe by IFRA.
- There are many new synthetic aromas that bear no olfactory relationship to any natural material and yet modern perfumery depends on these new odours for the infinite variety of perfumes available today. Many synthetics have very beautiful aromas not available in Nature.
- Perfume composed only of expensive natural materials could be very expensive. Synthetic aromatics make possible perfumes at reasonable prices.
- In the distillation of natural essential oils any pesticides, herbicides, or fungicides that have been applied while the plant is growing may be concentrated into the essential oil making the oil toxic. Unless the essential oil is distilled from a Certified Organic origin, it may be dangerous.