ISO 21631:2020

Overview

ISO 21631:2020 specifies quality characteristics for the essential oil of clementine (Citrus clementina), Spanish type to facilitate consistent assessment and trade. It defines physical properties, a normative chromatographic profile (gas chromatography), sampling volume, packaging/labeling guidance references, and informational data such as a mean flash point. The standard is intended to ensure reproducible identity and quality evaluation of Spanish‑type clementine oil.

Key Topics and Requirements

The standard covers measurable technical criteria and test methods, including:

• Physical properties

  • Relative density at 20 °C: 0.840–0.860 (ISO 279)
  • Refractive index at 20 °C: 1.470–1.478 (ISO 280)
  • Optical rotation at 20 °C: +90° to +98° (ISO 592)
  • Acid value: max 0.2 (ISO 1242)
  • Appearance: clear mobile liquid; colour pale to dark orange; odor citrus/mandarin

• Chromatographic profile (normative)

  • Analysis by gas chromatography in accordance with ISO 11024. Representative component ranges include:
    • Limonene: 90.0–97.0% (major component)
    • Myrcene: 1.0–2.5%
    • α‑Pinene: 0.3–0.9%
    • Sabinene: 0.3–1.5%
    • Decanal: 0.1–0.4%
    • Linalool: 0.1–0.6%
    • Plus several components allowed only in traces (e.g., β‑pinene, (E)‑β‑ocimene, γ‑terpinene, α‑terpineol, neral/geranial, sinensals, N‑methyl methylanthranilate).
  • The chromatographic profile is normative, so proportions reported by the integrator must fall within the specified ranges.

• Sampling and testing

  • Sampling per ISO 212; minimum test sample volume 50 ml.
  • Flash point (informative mean): +50 °C (Pensky‑Martens apparatus) - provided for safety/transport information.

• Packaging, labelling and storage

  • Follow ISO/TS 210 (packaging/storage) and ISO/TS 211 (labelling/marking).

Applications and Who Uses This Standard

ISO 21631:2020 is used by:

• Essential oil producers and packers (quality specification for Spanish clementine oil)
• Analytical laboratories and QC teams (gas chromatography profiling and physico‑chemical testing)
• Flavor, fragrance and cosmetic manufacturers (raw material acceptance criteria)
• Traders, importers/exporters and procurement departments (specification for contracts)
• Transport, insurance and regulatory bodies (flash point and safety information)
• Standardization and conformity assessment bodies

Related Standards

Relevant referenced documents include: ISO/TS 210, ISO/TS 211, ISO 212, ISO 279, ISO 280, ISO 592, ISO 1242, ISO 11024 and informative guidance ISO/TR 11018, ISO/TR 21092.

Keywords: ISO 21631:2020, essential oil of clementine, Spanish type, chromatographic profile, gas chromatography, limonene, quality assessment, flash point, sampling, refractive index.