Overview
ISO 856:2006 - Oil of peppermint (Mentha × piperita L.) defines quality characteristics and test requirements for peppermint essential oil to facilitate consistent assessment and trade. Because peppermint oils from different origins are hard to distinguish by single values, the standard groups oils from USA, United Kingdom, France, Italy, India and China and gives a normative chromatographic profile and physical/chemical limits applicable to commercial peppermint oil.
Key topics and technical requirements
- Appearance, colour, odour: clear mobile liquid; almost colourless to pale greenish‑yellow; characteristic minty, sweet, menthol‑like aroma (origin variations allowed).
- Physical constants:
- Relative density at 20 °C: Origins other than US: 0.898–0.918; US type: 0.899–0.911.
- Refractive index at 20 °C: 1.459–1.465 (approx.).
- Optical rotation at 20 °C: Origins other than US −30° to −14°; US type −32° to −18°.
- Miscibility in 70% ethanol (v/v): clear solution achievable with max 5 volumes ethanol per 1 volume oil (non‑US); max 3 volumes for US type.
- Acid value: maximum 2.
- Chromatographic profile (normative): Analysis by gas chromatography is required. ISO 856 provides a list of representative components with percentage ranges (examples): menthol (≈32–49% / 36–46%), menthone (≈13–28% / 15–25%), 1,8‑cineole, menthofuran, isomenthone, neomenthol, pulegone, limonene, menthyl acetate, β‑caryophyllene, etc. The profile is used to verify authenticity and type (US vs other origins).
- Flashpoint: informative mean value +66 °C (Setaflash).
- Sampling, test methods, packaging and storage: references to established ISO test methods are specified.
Applications and users
ISO 856:2006 is used by:
- Essential‑oil producers and distillers for quality specification and lot release.
- Analytical and QC laboratories performing gas chromatography and physico‑chemical tests.
- Perfume, flavor and cosmetics manufacturers verifying raw‑material compliance.
- Traders, buyers and specifiers for procurement and contractual quality clauses.
- Transport, safety and regulatory personnel for hazard information (flashpoint guidance).
Related standards
Normative and informative references in ISO 856 include ISO/TR 210, ISO/TR 211, ISO 212 (sampling/packaging), ISO 279 (relative density), ISO 280 (refractive index), ISO 592 (optical rotation), ISO 875 (miscibility), ISO 1242 (acid value) and ISO 11024‑1/2 (chromatographic profiles). These support test methods and presentation of GC data.
