Fragrance is a complex mixture of chemicals that can convey a scent, mask an odor, or both. These substances can come from natural sources (plants, flowers, food) or synthetically manufactured in laboratories. The latter is the type of fragrance you might find in a perfume, cologne, or room spray, as well as scented personal care and cleaning products. Manufacturers don’t have to disclose the ingredients on their product labels, but they must list them on a safety data sheet. Fragrance is made up of more than 3,500 chemicals, some of which are linked to a range of health problems.
Perfumes are comprised of three structural parts: head, middle, and base notes. The head note is the first impression a person gets from the scent, which evaporates quickly (5-30 minutes after application). Top notes can include citrus, light fruits, and herbs (sage, lavender) [1].
The middle note compounds give the perfume its body and character, lingering just prior to the departure of the head notes. This is where the cologne’s personality comes out, and it is also where some of the more allergenic chemicals such as linalool and hexyl cinnamal appear [2].
The base note, or musk, provides depth to the perfume and anchors the scent, giving it stability. The musk family is a common allergen, and compounds like ambroxan and methyl hexyl salicylate are linked to skin rashes.