Fragrance is a combination of scent chemicals and other ingredients used to create the distinctive smell of perfume. Fragranced products are used in cosmetics such as bath and body products, personal care items and in fragranced hair products. They may also be used as fragranced candles, incense, room sprays and other household products. Fragrance chemicals are often associated with allergies, dermatitis and respiratory distress. The word “fragrance” or “parfume” on a product label represents an undisclosed mixture of scent chemicals and ingredients, many of which have been associated with respiratory problems, skin irritability and reproductive distress.
A perfume can contain up to 100 different chemicals. A perfume has three structural parts: a top note, which is the fresh, volatile odour that appears for 5-30 minutes after application; middle notes, or modifiers, which add fullness to the perfume; and base notes, which are the foundation of the scent and provide the longest lasting impression. The base note compounds give the perfume its richness and solidity.
The odour of a perfume is produced by combining natural raw materials and synthetic chemicals in the blending process. The natural raw materials are usually plant-derived essential oils (q.v.) extracted by steam distillation, water distillation or solvent extraction. The delicate flowers used in a perfume can be extracted by the method of enfleurage, wherein the petals are placed between layers of purified animal fat that become saturated with flower oil. The fat is then removed and the flower oil, called an absolute, is obtained by treatment with alcohol.
Other raw materials are synthetic aromatics, which can be produced cheaply by chemical synthesis and that provide fragrances not easily obtained from the natural world. For example, the odour of a freshly cut orchid is difficult to obtain from natural sources, but can be replicated using synthetic chemicals such as calone and coumarin.
A perfume may also include a range of other additives including colorants, stabilizers and preservatives. The scent of a perfume is released into the air by the person wearing it, and left behind on clothing and other fabric. This trail of scent is called sillage and can be noticed by others, depending on the strength of the perfume and how it is worn.
The fragrance industry has maintained a strict system of safety assurance for over 30 years, based on a thorough scientific evaluation of ingredients by the Research Institute for Fragrance Materials, Inc., an independent nonprofit organization. This program includes testing for human health, environmental and allergic reactions, adsorption and degradation, group sensitization and use level tests. In addition, the perfume industry publishes a database of all known chemicals associated with adverse health effects. This information is available on the Web. The RIFM also maintains an extensive scientific reference library on fragrance materials. The RIFM’s scientific staff has been trained to evaluate new fragrance raw materials and to perform risk assessments when necessary. The results of RIFM’s work are incorporated into national and international regulations on the safety of cosmetic and personal care products.