Overview
ISO 21043-3:2025 - Forensic sciences - Part 3: Analysis specifies requirements and recommendations to safeguard the forensic analysis of items of potential evidential value. It sets out how forensic service providers should select and apply suitable methods to meet a customer’s request, ensuring suitable methods, proper controls, qualified personnel and appropriate analytical strategies. The standard applies to activities at the scene and in facilities across forensic disciplines, excluding digital data recovery (see ISO/IEC 27037).
Key topics and technical requirements
- Documented procedures for analysis, including method limitations, sampling, preparation, and controls.
- Method validation and verification: validate new methods and verify externally validated methods before use; include performance characteristics such as precision, accuracy, LOD/LOQ, specificity, robustness and carry-over.
- Equipment, consumables and software control: unique identification, version records, maintenance, and pre-use checks.
- Calibration and performance checks with retained records that show identity, dates, results and corrective actions.
- Metrological traceability and use of certified reference materials where measurement reliability is required.
- Reference and control samples, collections and databases: unique identification, documented origin, storage to prevent loss or contamination, and expiry management.
- Measurement uncertainty and significant figures: documented procedure to estimate uncertainty considering sampling and analysis components; include uncertainty in validation of quantitative methods.
- Personnel, facilities and environmental conditions: competence, facility suitability and environmental monitoring to avoid impacts on observations.
- Acceptance/rejection of requests and items and analytical strategy: assessment prior to analysis, method selection, item selection/sampling, recording deviations and ensuring reliability of observations.
- Purpose-driven analysis: guidance for classification/identification, quantification, source attribution and reconstruction.
Applications and practical value
ISO 21043-3 is used to:
- Develop and maintain laboratory SOPs and analytical workflows that meet internationally recognized forensic requirements.
- Ensure defensible method selection, validation and documentation for court-admissible evidence.
- Guide procurement and quality control of equipment, consumables and reference materials.
- Support quality assurance, training and competence assessment of forensic personnel.
- Improve reproducibility and reliability of forensic results across disciplines (trace evidence, toxicology, chemistry, biology, etc.).
Who should use this standard
- Forensic service providers (crime labs, university labs, private forensic practitioners)
- Quality managers and technical leads responsible for method validation and ISO/IEC 17025 alignment
- Procurement officers, forensic scientists and legal professionals evaluating evidence integrity
Related standards
Keywords: ISO 21043-3, forensic analysis, method validation, measurement uncertainty, metrological traceability, forensic service provider, analytical strategy.