ISO 3961-2024 PDF

Full title and description

St ISO 3961-2024 — "Animal and vegetable fats and oils — Determination of iodine value". This international standard specifies a reference (laboratory) method for determining the iodine value (IV) of animal and vegetable fats and oils; it also includes an informative annex describing a method to calculate IV from fatty‑acid composition data.

Abstract

ISO 3961:2024 provides the established reference titrimetric procedure used to quantify the iodine value (IV) of fats and oils. Annex B describes a calculation method to derive IV from fatty‑acid compositional data (based on established AOCS practice), with explicit exclusions and caveats (for example, the calculation method is not applicable to fish oils and results for cold‑pressed, crude, unrefined or partially hydrogenated oils may differ).

General information

• Status: Published.
• Publication date: 19 December 2024 (ISO edition 7, 2024‑12).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 67.200.10 (Fats and oils).
• Edition / version: 7 (2024).
• Number of pages: 11 pages (published technical text).

Scope

This standard specifies a reference analytical method for the determination of the iodine value (IV) of animal and vegetable fats and oils. It includes procedural details for sample preparation and titration, and an informative annex giving a calculation method to obtain IV from fatty‑acid composition; that annex is explicitly not applicable to fish oils and may yield differing results for crude, cold‑pressed or partially hydrogenated oils. The standard is maintained by ISO/TC 34/SC 11 (fats and oils).

Key topics and requirements

• Definition and significance of iodine value (IV) as an index of unsaturation in fats and oils.
• Reference titrimetric procedure (sample mass selection, addition of halogenating reagent such as Wijs reagent, reaction, back‑titration) — procedural parameters and accuracy requirements.
• Sample preparation requirements and guidance (including cross‑references to related ISO sample‑prep methods such as ISO 661 where appropriate).
• Calculation formulae and reporting instructions for iodine value.
• Informative Annex B: calculation of IV from fatty‑acid compositional data (based on AOCS Official method Cd 1c‑85), with scope limitations and notes about impurities and thermal degradation effects.
• Precision and repeatability expectations appropriate for a reference method; laboratory practice and record keeping.

Typical use and users

Laboratories performing quality control, official testing and research on edible and technical fats/oils (e.g., oilseed crushers, refiners, food manufacturers, analytical service labs, research institutes) use ISO 3961:2024 as the reference method for iodine value determination. Regulators and standards bodies also refer to this method when setting specifications or verifying compliance.

Related standards

Closely related documents and references include earlier editions of ISO 3961 (withdrawn), ISO methods for sample preparation such as ISO 661, and the AOCS Official methods referenced in Annex B (AOCS Cd 1c‑85). The standard sits within the ISO/TC 34/SC 11 family of standards for fats and oils.

Keywords

iodine value; IV; fats and oils; animal fats; vegetable oils; titration; Wijs reagent; fatty‑acid composition; AOCS Cd 1c‑85; ISO/TC 34/SC 11.

FAQ

Q: What is this standard?

A: ISO 3961:2024 is the international reference method for determining the iodine value (IV) of animal and vegetable fats and oils. It defines the laboratory titrimetric procedure and an informative calculation annex.

Q: What does it cover?

A: It covers sample preparation and a titration‑based analytical procedure to measure IV, calculation and reporting rules, precision requirements for a reference method, and an Annex (B) for calculating IV from fatty‑acid composition (with stated limitations, e.g., not for fish oils).

Q: Who typically uses it?

A: Chemical and food‑analysis laboratories, oil processors and refiners, research institutes, conformity assessment bodies and regulators that need a traceable, standardized measurement of unsaturation in fats and oils.

Q: Is it current or superseded?

A: Current — ISO 3961:2024 (7th edition) was published in December 2024 and supersedes the 2018 edition. Users should adopt the 2024 edition for reference testing and cite it when reporting results.

Q: Is it part of a series?

A: It is part of the body of ISO standards maintained by ISO/TC 34/SC 11 covering methods and specifications for animal and vegetable fats and oils; it updates and replaces earlier editions of ISO 3961. Annex B references established AOCS calculation practice, linking it to analytical method families in lipid analysis.

Q: What are the key keywords?

A: Iodine value, iodine index, fats and oils, titration, Wijs reagent, fatty‑acid composition, AOCS Cd 1c‑85, ISO 661, ISO/TC 34/SC 11.