Overview
ISO/TR 79:2015 - Reference materials - Examples of reference materials for qualitative properties - is an ISO Technical Report that summarizes the state of the art for producing, certifying and characterizing reference materials (RMs) used to support qualitative (nominal) properties. Rather than prescribing a single international guidance, ISO/TR 79:2015 collects practical examples and approaches from a range of producers and users to inform ongoing development of harmonized guidance on RMs for qualitative identification, classification and nominal properties.
Key examples presented in the report include:
- RMs certified for DNA sequence identity
- Organic chemicals characterized for identification
- Human biospecimens certified for qualitative properties
- A RM for darnel seed identity
- Colour classification of freshwater cultured pearls
- European Pharmacopoeia reference standards for qualitative analysis
Key topics and technical issues
ISO/TR 79:2015 highlights technical topics and pragmatic considerations that RM producers and users must address when dealing with qualitative properties:
- Processing and production approaches for different material types (DNA, biospecimens, organic compounds)
- Purity assessment and how it affects qualitative identification
- Characterization methods (e.g., sequencing, spectrometry) used to establish identity or classification
- Suitability, homogeneity and stability studies tailored to qualitative use
- Identification probability and expression of confidence in qualitative results
- Documentary and metrological traceability for qualitative RMs
- Challenges in defining uncertainty and expressing confidence for qualitative outcomes
- Terminology issues: varying use of “qualitative properties”, “nominal properties”, and how different fields treat order/ordinal properties
Practical applications and users
This Technical Report is useful to organizations involved in:
- Reference material producers and accreditation bodies
- Clinical and forensic laboratories, tissue banks and biorepositories
- Pharmaceutical quality control and pharmacopoeial authorities
- Food safety, agricultural testing and botanical identity labs
- Standardization committees and metrology bodies developing guidance for qualitative RMs
ISO/TR 79:2015 helps these users understand current best practices, methodological examples and open issues that must be resolved to create internationally harmonized guidance.
Related standards and initiatives
- ISO Guide 35 and ISO Guide 80 (principles commonly referenced)
- ISO Guide 34 and ISO/IEC 17020 (accreditation frameworks mentioned)
- JCGM/VIM work on extending the International Vocabulary of Metrology to nominal/qualitative properties
- AOAC International guidance on validation of qualitative binary chemistry methods
ISO/TR 79:2015 is a reference source for practitioners and policymakers working toward standardized, traceable, and fit‑for‑purpose reference materials for qualitative analysis.