Overview
EN ISO 13843:2017 (ISO 13843:2017) - Water quality - Requirements for establishing performance characteristics of quantitative microbiological methods - defines how to characterize quantitative microbiological methods used for water analysis. It describes procedures to determine the method performance characteristics that support subsequent method validation or single-laboratory verification. The standard emphasizes selective quantitative methods and applies to all types of water; applicability to non-standard counting approaches (neither direct microscopic, colony count nor MPN-based) should be assessed carefully. EN ISO 13843:2017 supersedes ENV ISO 13843:2001 and updates earlier technical reports.
Key Topics
This standard focuses on measurable parameters and experimental designs to describe method behaviour in defined conditions. Major technical topics include:
- Characterization concepts and definitions (performance characteristics).
- Categorical performance: sensitivity, specificity, efficiency, selectivity, false positive and false negative rates.
- Quantitative performance: working range, upper and lower limits of detection, linearity considerations.
- Precision: repeatability, intralaboratory reproducibility and interlaboratory reproducibility.
- Robustness: effects of time, temperature and operational variation.
- Relative recovery and sample matrix effects.
- Uncertainty of counting for colony counts and MPN results.
- Experimental designs for determining performance characteristics, including protocols for single-laboratory verification and collaborative studies.
- Supporting annexes with mathematical models, assessment procedures and glossary of symbols.
Applications
EN ISO 13843:2017 is intended for practical use by:
- Water testing laboratories establishing or documenting method performance for routine testing.
- Method developers and manufacturers who need to provide performance data for new quantitative microbiological assays.
- Accreditation bodies and quality managers applying ISO/IEC 17025 criteria for method validation and verification.
- Regulatory agencies and water utilities assessing compliance and comparability of microbiological data.
- Public health and environmental laboratories conducting method comparisons, interlaboratory studies, or implementing standard operating procedures (SOPs).
Practical outputs include validated method performance reports, acceptance criteria for routine use, and design templates for collaborative studies and single-laboratory verification.
Related Standards
- ISO 13843 is produced by ISO/TC 147 (Water quality).
- Often used alongside ISO/IEC 17025 (laboratory competence) and ISO 5667 series (water sampling) when implementing comprehensive water quality monitoring programs.
Keywords: EN ISO 13843:2017, ISO 13843, water quality, microbiological methods, method validation, sensitivity, specificity, repeatability, reproducibility, limit of detection, uncertainty of counting.
