Overview
ISO/TS 5594:2022 - Soil and water quality: Guidance and requirements for designing an interlaboratory trial for validation of biotests - provides structured guidance for planning, organizing and evaluating interlaboratory validation studies for biological test methods (biotests). It supports method developers and lead laboratories in estimating method precision, transferability and, where relevant, measurement trueness for ecotoxicological and microbiological biotests applied to soils, sediments and waters.
Key topics and requirements
- Validation workflow: Describes a three-step validation program - prevalidation, demonstration of laboratory readiness and capability, and the formal interlaboratory method validation round(s).
- Performance characteristics: Guidance on assessing precision (repeatability, reproducibility), measurement trueness, and other performance characteristics relevant to biotests.
- Study design: Requirements for participating laboratories, sample selection (contaminated soils, amended soils, wastewaters, sediments, eluates, etc.), experimental design, control materials and endpoints.
- Laboratory qualification: Procedures to demonstrate participating laboratories’ readiness (equipment, organisms/cultures) and capability (control performance, reference compound responses) before the main validation.
- Data analysis and statistics: Directions for evaluating intra- and interlaboratory variability and estimating repeatability when repeated runs are limited (see Annexes A–C for accuracy, repeatability estimation and uncertainty calculation).
- Documentation and reporting: Expectations for lead laboratory responsibilities, reporting formats and validation conclusions.
- Practical annexes: Informative annexes include validation schema (Annex D), example questionnaires (Annex E), and specific features for terrestrial (Annex F) and water biotests (Annex G), plus summaries of past trials (Annexes H–I).
Applications and intended users
- Who uses it: Lead laboratories, method developers, standardization committees, ecotoxicologists, water and soil quality laboratories, and regulators involved in method standardization.
- Practical use cases:
- Designing interlaboratory trials to validate a new or revised biotest standard.
- Demonstrating transferability and reproducibility of ecotoxicological assays across laboratories.
- Estimating uncertainty, precision and trueness for methods reporting quantitative outcomes (e.g., biological equivalence concentrations).
- Establishing validity criteria and acceptance limits for routine testing and accreditation.
Related standards
- ISO 5725‑1 (precision terminology and concepts), ISO 23196 (biological equivalence reporting), and ISO/IEC Guide 99 (measurement trueness terminology) are relevant references cited in ISO/TS 5594:2022 for statistical and metrological context.
Keywords: ISO/TS 5594:2022, interlaboratory trial, biotest validation, soil and water quality, method validation, repeatability, reproducibility, measurement trueness, lead laboratory.