Overview
ISO/TS 22176:2020 - "Cosmetics - Analytical methods - Development of a global approach for validation of quantitative analytical methods" provides a standardized, global approach for validating quantitative analytical methods used in the cosmetics sector. The document centers on the construction and interpretation of an accuracy profile (total error concept) and specifies a characterization procedure suitable for internal laboratory validation and for interpreting interlaboratory studies designed per ISO 5725‑1. It applies only to fully developed methods (selectivity/specificity and scope already defined) and explicitly excludes microbiological trials.
Key topics and requirements
- Accuracy profile / total error: Validation is based on plotting accuracy versus concentration to assess whether measured results meet predefined acceptance limits across the working range.
- Tolerance interval and β proportion: The procedure defines calculation of tolerance intervals that should contain a chosen proportion (β) of future measurements; methods are validated if these intervals lie within acceptance limits.
- Defined scope: Validation applies to specific measurands, matrices and analyte concentration ranges already established during method development.
- Characterization plan: Requirements for selecting validation samples, reference value establishment, numbers of series, repetitions and concentration levels are specified.
- Calibration and indirect methods: Guidance on calibration planning, model selection, inverse prediction and calculation of predicted concentrations for indirect measurement methods.
- Precision and trueness: Calculation methods for repeatability, intermediate precision and reproducibility are included (see Annex A).
- Decision rules and routine management: Rules for interpreting the accuracy profile, defining the validated scope, selecting routine calibration, identifying outliers and managing ongoing performance.
- Supporting material: Normative and informative annexes cover calculation methods, contents of validation files and illustrative examples for a cosmetic analyte (e.g., Annex C), plus discussion on β influence and uncertainty contributions.
Applications and who should use it
ISO/TS 22176:2020 is practical for:
- Cosmetic testing laboratories performing quantitative chemical analyses
- Method developers finalizing validation for routine use
- Quality assurance and QC managers implementing ISO/IEC 17025–aligned validation procedures
- Accreditation bodies and regulators evaluating analytical method validation records
- Laboratories conducting interlaboratory studies that follow ISO 5725‑1 recommendations
Benefits include improved harmonization of validation practices across diverse cosmetic matrices, clearer demonstration of method accuracy/uncertainty and stronger support for compliance and decision-making.
Related standards
- ISO/IEC Guide 99 (VIM) - metrology vocabulary and concepts
- ISO 5725‑1 - precision of measurement methods and results (interlaboratory study design)
- ISO/IEC 17025 - general requirements for the competence of testing and calibration laboratories
Keywords: ISO/TS 22176:2020, cosmetics, analytical methods, validation, accuracy profile, quantitative analytical methods, precision, trueness, tolerance interval, ISO 5725-1, ISO/IEC 17025.