Latest reviewed evidence
ISO 3217:1974 remains current for Cymbopogon citratus oil and specifies relative density from 0.872 to 0.897 at 20/20 degrees Celsius, refractive index from 1.4830 to 1.4890 at 20 degrees Celsius, optical rotation from minus 3 to plus 1 degree and at least 75 percent carbonyl compounds expressed as citral. ISO 4718:2004 separately covers Cymbopogon flexuosus oil and was confirmed in 2023. These are species-specific oil-quality boundaries, not results for an untested lot, food-grade evidence, current supply or live price.
ISO Cymbopogon citratus oil relative-density lower bound
0.872
relative density at 20/20 degrees Celsius · ISO 3217:1974, confirmed 2021
ISO Cymbopogon citratus oil relative-density upper bound
0.897
relative density at 20/20 degrees Celsius · ISO 3217:1974, confirmed 2021
ISO Cymbopogon citratus oil refractive-index lower bound
1.483
refractive index at 20 degrees Celsius · ISO 3217:1974, confirmed 2021
ISO Cymbopogon citratus oil refractive-index upper bound
1.489
refractive index at 20 degrees Celsius · ISO 3217:1974, confirmed 2021
ISO Cymbopogon citratus oil optical-rotation lower bound
-3
degrees at 20 degrees Celsius · ISO 3217:1974, confirmed 2021
ISO Cymbopogon citratus oil optical-rotation upper bound
1
degrees at 20 degrees Celsius · ISO 3217:1974, confirmed 2021
ISO Cymbopogon citratus oil citral-expression floor
75
percent carbonyl compounds expressed as citral, minimum · ISO 3217:1974, confirmed 2021
Cymbopogon citratus and Cymbopogon flexuosus stay species-specific
Kew accepts Cymbopogon citratus and Cymbopogon flexuosus as separate species. ISO follows the same split in its oil standards: ISO 3217 covers C. citratus, while ISO 4718 covers C. flexuosus. Atlas records the accepted botanical name, cultivar or chemotype where evidenced, growing and processing origin, and identity method. A common-name declaration of lemongrass alone does not establish species or make two oils or herbs equivalent.
Fresh herb, dried leaves, ground material and essential oil are different products
Kew documents culinary stems and leaves as well as extracted aromatic oil. The Codex spices committee records ISO/AWI 25261 as a standard under development for dried C. citratus leaves in whole or ground form, while ISO 3217 and ISO 4718 address essential oils. Atlas keeps fresh stalk or leaf, dried whole leaf, cut or ground herb, planting material and distilled oil separate, with intended food, flavour, fragrance or other use and the applicable destination requirements.
Oil quality numbers require species, method and lot evidence
ISO 3217's density, refractive-index, optical-rotation and citral-expression limits apply to C. citratus oil under named conditions. ISO 4718 is a separate quality standard for C. flexuosus oil. Atlas preserves species, extraction and distillation method, fraction or blend status, appearance and odour, density and temperature, refractive index and temperature, optical rotation, chromatographic or carbonyl method, result basis, laboratory, sample, certificate, lot and test date. A value detached from those fields does not verify another shipment.
A botanical identity or oil standard does not establish a delivered lemongrass price
An accepted species name, an oil-quality limit or a developing dried-leaf specification does not establish freshness, moisture, particle size, volatile-oil content, pesticide or microbiological status, adulteration, current availability, transaction value, freight or destination cost for a present lot. A delivered comparison still needs permitted current observations for the exact species and form, grade and test evidence, package, origin, quantity, currency, Incoterm, destination, delivery window, route costs and information vintage. Atlas withholds a physical estimate when those observations or usage rights are missing.