ISO 3033-2:2005

Overview

ISO 3033-2:2005 - "Oil of spearmint - Part 2: Chinese type (80 % and 60 %) (Mentha viridis L. var. crispa Benth.), redistilled oil" - is an international standard that defines quality characteristics and test methods for redistilled Chinese-type spearmint oil. The standard facilitates consistent assessment of spearmint oil used in flavor, fragrance and related industries by specifying physical and chromatographic requirements for two carvone-enriched grades (commonly referred to as 80% and 60% carvone types).

Key topics and technical requirements

• Scope: Applies to redistilled oil obtained from Mentha viridis L. var. crispa Benth. and defines characteristics to assess quality.
• Appearance, colour and odour: Clear, mobile liquid; colour from colourless to pale yellow; characteristic carvone herbaceous odour.
• Chromatographic profile (normative): Gas chromatography is required to identify and quantify representative components. The standard lists component ranges for the Chinese type 80% and 60% (e.g., carvone approx. 78–84% for 80% grade and 57–66% for 60% grade). Other indexed components include limonene, menthone, cis-/trans-dihydrocarvone, dihydrocarvyl acetates and minor terpenes.
• Physical constants:
  • Relative density (d20): Specified ranges for each grade (e.g., ~0.942–0.955 for 80%).
  • Refractive index (n20): Given ranges (e.g., ~1.488–1.496 for 80%).
  • Optical rotation: Specified intervals (e.g., −55° to −50° for 80%).
  • Miscibility in 70% ethanol: Shall be soluble using no more than three volumes of 70% ethanol per one volume of oil.
• Carbonyl value: Minimum analytical thresholds are defined and related to carvone content (carvone expressed as carbonyl compound).
• Flashpoint: Informative annex reports mean flashpoints measured (Setaflash) - approximately +58 °C for the 60% type and +74 °C for the 80% type.
• Test methods & sampling: Analytical methods reference ISO standards for gas chromatography and physical tests (ISO 11024 series, ISO 279, ISO 280, ISO 592, ISO 1271). Minimum test sample volume: 50 ml.

Applications and who uses this standard

• Essential oil manufacturers and redistillers to certify product grade (60% vs 80% carvone).
• Quality control and analytical laboratories performing GC profiling and physical testing.
• Flavor and fragrance formulators who require consistent spearmint oil composition.
• Buyers, traders and regulators verifying product conformity for trade, labeling, transport and safety.
• Packaging and storage professionals following guidance for conditioning and marking.

Related standards

• ISO 3033 (other parts): Part 1 (native type), Part 3 (Indian type), Part 4 (Scotch variety)
• Referenced test and guidance standards: ISO 11024-1/2, ISO 1271, ISO 279, ISO 280, ISO 592, ISO/TR 210, ISO 212, ISO/TR 211, ISO/TR 11018

Keywords: ISO 3033-2:2005, oil of spearmint, spearmint oil Chinese type, carvone content, gas chromatography, essential oils standard, spearmint oil quality, refractive index, relative density, flashpoint.