ISO 4323-2018 PDF

Full title and description

ISO 4323:2018 — Soaps — Determination of chloride content — Potentiometric method. This international standard specifies a potentiometric titration procedure for the quantitative determination of chloride in soaps (including soaps that contain other surface-active agents) and in compounded soap products.

Abstract

ISO 4323:2018 defines a potentiometric titration method in which chloride ions are titrated with a standard silver nitrate solution in an acid medium using an ion-selective (silver/silver chloride) electrode and an appropriate reference electrode. The procedure covers sample preparation, titration end‑point detection by potentiometry, calculation of chloride content and basic performance/accuracy considerations for routine laboratory quality control of soap products.

General information

• Status: Withdrawn (stage: withdrawal of the International Standard).
• Publication date: December 2018 (published 7 December 2018 as part of the 2018 edition cycle).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 71.100.40 (surface‑active agents / soaps).
• Edition / version: Edition 2 (2018).
• Number of pages: 6 (official ISO publication length).

Scope

This standard applies to the determination of chloride content in solid and liquid soap formulations and compounded soap products, whether or not other surface‑active agents are present. It specifies sample preparation, the potentiometric titration technique using silver nitrate in a nitric acid medium, electrode requirements, calculation of results and presentation of data suitable for laboratory quality control and specification testing.

Key topics and requirements

• Applicability to soaps and compounded soap products (including those containing other surface‑active agents).
• Sample preparation and dissolution specific to soap matrices prior to titration.
• Use of a standard volumetric silver nitrate solution as titrant in a nitric acid medium.
• Potentiometric end‑point detection using a silver/silver chloride measuring electrode with an appropriate reference electrode (historically a calomel reference is described).
• Calculation and expression of chloride content, reporting formats and basic precision/accuracy expectations for routine QC.
• Notes on possible interferences and limitations inherent to potentiometric chloride determination in complex soap matrices.

Typical use and users

This standard is used by industrial quality control laboratories in soap and detergent manufacturing, independent testing laboratories, regulatory and standards bodies, and research groups working on surfactant and soap formulation. It is intended for analysts performing routine chloride determinations as part of product specification testing and raw material qualification.

Related standards

ISO 4323:2018 replaces the earlier ISO 4323:1977 and has itself been noted in bibliographic records as withdrawn and revised (a later revision is referenced as ISO 4323:2025 in cataloging records). National/adopted versions (for example BS ISO 4323:2018) reflect the same method. For laboratory accreditation and chemical testing practice see complementary standards on laboratory competence and titrimetric methods.

Keywords

soaps; chloride content; potentiometric titration; silver nitrate titration; silver/silver chloride electrode; surface‑active agents; quality control; ISO 4323.

FAQ

Q: What is this standard?

A: ISO 4323:2018 is an international standard that specifies a potentiometric method for determining chloride content in soaps and compounded soap products.

Q: What does it cover?

A: It covers sample preparation for soap matrices, titration with standard silver nitrate in a nitric acid medium, potentiometric end‑point detection using appropriate electrodes, calculation and reporting of chloride results, and basic method performance notes.

Q: Who typically uses it?

A: Manufacturers of soaps and related surfactant products, contract testing laboratories, standardization bodies and QC/analytical chemists performing routine chloride determinations.

Q: Is it current or superseded?

A: ISO 4323:2018 is listed as withdrawn in ISO cataloging records. It replaced ISO 4323:1977 when published in 2018 and bibliographic records indicate it has subsequently been revised/replaced by a later ISO 4323 edition (catalog entries reference an ISO 4323:2025 revision). Users should check the current ISO catalog or national standards body to confirm the definitive current status before relying on the method for regulatory use.

Q: Is it part of a series?

A: It is part of the body of ISO standards developed under ISO/TC 91 (surface‑active agents) covering analytical methods and specifications for soaps and surfactants; it directly revises the earlier ISO 4323:1977.

Q: What are the key keywords?

A: Soaps; chloride; potentiometric titration; silver nitrate; silver/silver chloride electrode; surface‑active agents; QC.