Overview
ISO 4718:2004 specifies quality characteristics for oil of lemongrass [Cymbopogon flexuosus] to facilitate assessment of its identity and purity. The standard defines physical properties, a normative gas‑chromatographic profile, sampling and minimum sample size, and references packaging/labeling and flash‑point information. ISO 4718:2004 is a technical revision prepared by ISO/TC 54 (Essential oils).
Key topics and requirements
- Identity and appearance
- Liquid, mobile, clear; color: pale yellow to yellowish‑brown; odor: powerful, green, citral‑like.
- Physical properties (specified limits)
- Relative density at 20 °C: minimum 0.885, maximum 0.905.
- Refractive index at 20 °C: minimum 1.4830, maximum 1.4890.
- Optical rotation at 20 °C: between −4° and +1°.
- Miscibility
- Miscible with 70% ethanol to give a clear solution using no more than 3 volumes of ethanol per 1 volume of oil.
- Chromatographic profile (normative)
- Gas chromatography is required (per ISO 11024‑1/‑2). The standard lists representative constituents and allowable ranges, for example:
- Neral: 25.0–35.0%
- Geranial: 35.0–47.0%
- Geraniol: 1.5–8.0%
- Geranyl acetate: 0.5–6.0%
- Limonene, 6‑methyl‑5‑hepten‑2‑one, caryophyllene with specified ranges
- The GC profile constitutes the accepted chemical fingerprint; example chromatograms and operating conditions are given in Annex A.
- Sampling and testing
- Minimum sample volume for testing: 25 ml.
- Test methods reference ISO series standards (density, refractive index, optical rotation, miscibility, GC).
- Flash point
- Informative average flash point: +89 °C (value obtained with a Pensky‑Martens apparatus); guidance in Annex B.
Applications and users
ISO 4718:2004 is used by:
- Essential oil producers and distillers for quality specification and batch release.
- Analytical laboratories performing GC identification and physico‑chemical testing.
- Buyers, traders and import/export agents for quality acceptance criteria.
- Fragrance, flavor, cosmetic and aromatherapy manufacturers requiring material specifications.
- Regulatory and standards bodies referencing accepted identity and purity limits.
Adoption of ISO 4718 supports consistent quality control, dispute resolution, and supply‑chain transparency for lemongrass essential oil.
Related standards
Key cross‑references include ISO/TR 210, ISO/TR 211, ISO 279, ISO 280, ISO 592, ISO 875, ISO 11024‑1/‑2, ISO/TR 11018, ISO/TR 21092. These give test methods, packaging/labeling rules and additional guidance for essential oils.
