WHO: Update of Guideline of Reference Standards

The WHO recently published the "Working document QAS/25.972" of the "WHO General guidelines for the establishment, maintenance and distribution of chemical reference substances" on the subject of reference standards on its website for comments. The comment period is planned until 7 May, 2025. The aim is to determine whether the current draft still reflects the current state of the art in science and technology, and whether changes and/or extensions are necessary.

Following the comment phase, a committee will review the feedback received and provide an initial updated draft. This draft is expected to be published on the WHO website in the first quarter of 2026, including the public comments.

The "Working document QAS/25.972" currently consists of the following chapters and subsections:

Introduction
Glossary

Part A. Primary chemical reference substances

A.1 Assessment of need for the establishment of chemical reference substances
A.2 Obtaining source material
A.3 Evaluation of chemical reference substances
A.3.1 Use in identification tests
A.3.2 Use in purity tests
A.3.3 Use in assays
A.3.4 Use in the calibration of an instrument
A.4 Chemical and physical methods used in evaluating chemical reference substances
A.4.1 Methods used to verify the identity of chemical reference substances
A.4.2 Methods used to determine the purity of chemical reference substances
A.5 Assignment of content
A.6 Handling and distribution of chemical reference substances
A.6.1 Packaging operations
A.6.2 Storage
A.6.3 Stability
A.6.4 Information to be supplied with chemical reference substances
A.6.5 Distribution and supply
A.6.6 Period of use

Part B. Secondary chemical reference substances

B.1 Assessment of need
B.2 Obtaining source material
B.2.1 Selection of candidate substance
B.2.2 Documentation to be supplied with the candidate reference substance
B.2.3 Initial testing for compliance with the requirements of the monograph
B.3 Packaging
B.4 Interlaboratory testing to establish the assigned content
B.4.1 Competence of the participating laboratories
B.4.2 Dispatch of the candidate materials 1
B.4.3 Test protocol
B.4.4 Evaluation of test results
B.4.5 Traceability
B.5 Adoption of the secondary reference substance
B.6 Retesting programme
B.7 Information to be supplied with secondary chemical reference substances
B.8 Period of use 1
B.9 Distribution and supply
References

Comments on the "Working document QAS/25.972" of the "WHO General guidelines for the establishment, maintenance and distribution of chemical reference substances" can be submitted via the WHO online platform or by email.