A fixative is a substance used to equalize the

vapor pressure Vapor pressure or equilibrium vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium vapor pressure is an indicat ...

s, and thus the volatilities, of the raw materials in a

perfume Perfume (, ) is a mixture of fragrance, fragrant essential oils or aroma compounds (fragrances), Fixative (perfumery), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agre ...

oil, and to increase the perfume's odour tenacity. In simple words, fixatives increase the time for which the scent of a perfume lasts. Fixatives can be resinoids (e.g. benzoin, labdanum,

myrrh Myrrh (; from an unidentified ancient Semitic language, see '' § Etymology'') is a gum-resin extracted from a few small, thorny tree species of the '' Commiphora'' genus, belonging to the Burseraceae family. Myrrh resin has been used ...

, olibanum,

storax Storax (; , ''stúrax''), often commercially sold as styrax, is a natural fragrant resin isolated from the wounded bark of ''Liquidambar orientalis'' Mill. (Asia Minor) and ''Liquidambar styraciflua'' L. (Eastern US, Mexico, Central America) (A ...

, tolu balsam),

terpenoid The terpenoids, also known as isoprenoids, are a class of naturally occurring organic compound, organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeabl ...

s (e.g. ambroxide), poly cyclic ketones (e.g. civetone and muscone), which were originally obtained from animals, but are now mostly chemically synthesized because the artificial methods are more economical, more consistent and more ethical (animals need to be killed or kept in captivity to collect the

secretion Secretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. In contrast, excretion is the removal of certain substances or waste products from a cell or organism. The classical mec ...

s from their perineal glands). Synthetic fixatives include substances of low volatility (e.g. diphenylmethane, dipropylene glycol (DPG), cyclopentadecanolide, ambroxide, benzyl salicylate) and virtually odorless

solvent A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...

s with very low vapor pressures (e.g. benzyl benzoate, diethyl phthalate, triethyl citrate).

References

Perfume ingredients {{cosmetics-chem-stub