3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||152.24 g/mol|
|Appearance||Pale yellow liquid|
|Boiling point||229 °C (444 °F; 502 K)|
|Vapor pressure||0.22mmHg (20°C)|
|R-phrases (outdated)||R36, R37, R38|
|NFPA 704 (fire diamond)|
|Flash point||91 °C (196 °F; 364 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Citral, or 3,7-dimethyl-2,6-octadienal or lemonal, is either a pair, or a mixture of terpenoids with the molecular formula C10H16O. The two compounds are double bond isomers. The E-isomer is known as geranial or citral A. The Z-isomer is known as neral or citral B.
Citral is present in the oils of several plants, including lemon myrtle (90-98%), Litsea citrata (90%), Litsea cubeba (70-85%), lemongrass (65-85%), lemon tea-tree (70-80%), Ocimum gratissimum (66.5%), Lindera citriodora (about 65%), Calypranthes parriculata (about 62%), petitgrain (36%), lemon verbena (30-35%), lemon ironbark (26%), lemon balm (11%), lime (6-9%), lemon (2-5%), and orange.
Citral has a strong lemon (citrus) odor. Neral's lemon odor is less intense, but sweeter. Citral is therefore an aroma compound used in perfumery for its citrus effect. Citral is also used as a flavor and for fortifying lemon oil. It also has strong antimicrobial qualities, and pheromonal effects in acari and insects.
Two studies showed 1-1.7% of people to be allergic to citral, with allergies frequently reported. Citral on its own is strongly sensitizing to allergies; the International Fragrance Association recommends that citral only be used in association with substances that prevent a sensitizing effect. Citral has been extensively tested, with no known genotoxicity or carcinogenic effect.