Overview
ISO 21390:2005 defines the requirements and test methods for the assessment of oil of wintergreen, China [Gaultheria yunnanensis (Franch.) Rehd.], specifically the redistilled essential oil. This International Standard enables consistent evaluation of oil quality and ensures global harmonization in trade, production, and regulatory compliance.
The standard, developed by ISO Technical Committee 54 (Essential Oils), details key characteristics, such as appearance, odour, physical properties, chromatographic profile, and provides related instructions for sampling, testing, packaging, labelling, and storage.
Key Topics
ISO 21390:2005 covers essential aspects for the quality control of Chinese oil of wintergreen:
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Definition and Scope
- Specifies oil of wintergreen, China, redistilled, obtained via steam distillation from leaves, stalks, and twigs of Gaultheria yunnanensis and further purified through redistillation.
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Physical Characteristics
- Appearance: Clear, transparent, mobile liquid.
- Colour: Colourless to slightly yellow.
- Odour: Strongly aromatic, sweet, and characteristic.
- Relative density at 20 °C: 1.160 - 1.195.
- Refractive index at 20 °C: 1.5230 - 1.5430.
- Optical rotation at 20 °C: between –1° and +1°.
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Chemical Characteristics
- Chromatographic profile: Major component is methyl salicylate (97 - 99.8%), along with trace levels of α-pinene, β-pinene, 1,8-cineole, linalool, and ethyl salicylate.
- Acid value: Maximum 1.5.
- Ester value: 338 – 380.
- Residue on evaporation: Maximum 0.1%.
- Miscibility: No more than four volumes of 80% ethanol for full miscibility.
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Flashpoint
- A mean value of +96 °C (closed cup) is specified for safe handling and transport.
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Sampling and Testing
- Provides minimum test sample volume (150 ml) and references to ISO methods for density, refractive index, optical rotation, miscibility, acid value, ester value, and chromatographic analysis.
Applications
ISO 21390:2005 supports a range of practical uses across industries:
- Quality Assurance: Ensures the essential oil meets consistent benchmarks, supporting suppliers and manufacturers in international trade.
- Regulatory Compliance: Facilitates adherence to import/export regulations and supports safety in transport and storage.
- Product Development: Guides cosmetics, pharmaceutical, and food companies in ingredient selection and specification.
- Research and Development: Assists laboratories and researchers with standardized methods for analysis and comparison.
- Procurement and Supply Chain: Provides objective criteria for purchase specifications and supplier audits.
Adherence to ISO 21390:2005 ensures customer confidence, product safety, and traceability for all stakeholders dealing with Chinese oil of wintergreen.
Related Standards
Several ISO standards are referenced in ISO 21390:2005, providing detailed methodologies and complementary requirements:
- ISO 279 - Determination of relative density at 20 °C.
- ISO 280 - Determination of refractive index.
- ISO 592 - Determination of optical rotation.
- ISO 709 - Determination of ester value.
- ISO 875 - Evaluation of miscibility in ethanol.
- ISO 1242 - Determination of acid value.
- ISO 4715 - Quantitative evaluation of residue on evaporation.
- ISO 11024-1 & ISO 11024-2 - Guidance on preparation and utilization of chromatographic profiles for essential oils.
- ISO/TR 210 & ISO/TR 211 - General rules for packaging, conditioning, labelling, and marking of essential oils.
- ISO/TR 11018 - Guidance on determination of flashpoint.
- ISO/TR 21092 - Characterization of essential oils.
Following ISO 21390:2005 alongside relevant standards provides a comprehensive framework for quality and safety in the essential oils industry, particularly in the sourcing and application of the oil of wintergreen, China.
