Fragrance is a mixture of more than 3,500 chemicals that give many personal care, cleaning and other products their unique smell. But some fragrance ingredients can be toxic, and exposure to them has been linked to health harms ranging from dermatitis to asthma, headaches to reproductive problems. And even though the word fragrance is listed on almost every product, manufacturers aren’t required to list individual scent chemicals on the label.
Fragrances are made from the vapors of odorous molecules that evaporate in the air, and they can be natural or synthetic. Companies that manufacture perfume and cologne purchase fragrance mixtures from perfume houses, which are companies that specialize in developing scents. These fragrances may contain natural or petroleum-derived raw materials, but most of today’s fragrances are composed from synthetic chemicals.
The most common method of producing a fragrance is by distillation, which involves heating aromatic compounds to high temperatures to evaporate the volatile chemicals, and then cooling them to extract the aromas. The resulting extracts are known as essential oils, tinctures and absolutes. These extracts must then be diluted to make them suitable for use in perfumes.
To create a fragrance, perfumers use a combination of ingredients that are added to a base, a carrier liquid or oil used to carry the scent in the skin. The base can be either a neutral-smelling vegetable oil, such as fractionated coconut oil or jojoba oil, or a fragrant alcohol like ethanol. The amount of dilution needed determines how strong the final perfume will be.
A perfume’s scent can be classified as part of a specific fragrance family, such as citrus, floral, oriental or woody. Perfumers often combine scents from different families to create more complex perfumes, and most fragrances contain aspects of more than one fragrance family. The fragrance family classification is not always completely objective or definitive, and even perfumes designated as single-scent tend to have subtle undertones of other scents.
Scents are grouped into fragrance families based on the types of odorous molecules they contain, which are then combined to form a specific scent. For example, a perfume containing bergamot and lavender is considered to be in the citrus family because a major portion of the scent consists of odorous molecules from these two sources. A fragrance containing rose and iris is called a floral fragrance because it combines the scents of these two flowers.
The term “fragrance” is generally synonymous with a pleasant odor and is usually applied to perfume, but the word can also be used to describe any kind of smell, good or bad. It is also a word that is often misused, with people using it ironically to mean something unpleasant or overpowering, such as “that perfume is so fragrant.” Neither the term fragrance nor its derivatives are scientifically defined. For further reading on this topic, see Scentsy’s article on the science behind fragrance.