ISO 4730:2017

Overview

ISO 4730:2017 - Essential oil of Melaleuca, terpinen-4-ol type (Tea Tree oil) - is an international standard that specifies the characteristics and quality criteria for Tea Tree essential oil (Melaleuca alternifolia or M. linariifolia). The document helps producers, quality control laboratories, buyers and regulators assess authenticity and conformity by defining physical properties, chromatographic profile requirements and additional informative data such as flashpoint and enantiomeric distribution.

Keywords: ISO 4730, Tea Tree oil, Melaleuca terpinen-4-ol, essential oil quality, chromatographic profile

Key Topics

• Identity and scope: Defines Tea Tree oil as the steam-distilled essential oil of Melaleuca, terpinen-4-ol type.
• Physical properties and limits:
  • Relative density at 20 °C: 0.885–0.906 (ISO 279)
  • Refractive index at 20 °C: 1.475–1.482 (ISO 280)
  • Optical rotation: +7° to +12° (ISO 592)
  • Miscibility in ethanol 85 %: clear solution with ≤ 2 volumes ethanol per 1 volume oil (ISO 875)
• Chromatographic profile (normative):
  • Gas chromatography analysis per ISO 11024 to determine component percentages.
  • Representative component ranges include (integrator %): terpinen-4-ol 35.0–48.0%, γ‑terpinene 14.0–28.0%, α‑terpinene 6.0–12.0%, α‑pinene 1.0–4.0%, α‑terpineol 2.0–5.0%. Some constituents (e.g., 1,8‑cineole, sabinene, globulol) are permitted only as traces or up to specified maxima. (Note: “traces” defined as