Overview
ISO 5667-3:2024 - Water quality - Sampling - Part 3: Preservation and handling of water samples is the sixth edition of the ISO guidance on how to preserve, handle, transport and store water samples for laboratory analysis. The standard covers procedures for physicochemical, chemical, hydrobiological, microbiological and radiochemical analyses and is intended mainly for situations where samples cannot be analysed on site and must be transported to a laboratory. ISO 5667-3:2024 updates the 2018 edition and adds validated guidance (including a flow diagram) and annexes on preservation techniques and container preparation.
Key topics and technical requirements
- Scope and applicability: Defines which analyses are covered (physicochemical, chemical, hydrobiological, microbiological, radiochemical) and which are excluded (ecotoxicological assays, biological assays, passive sampling, microplastics-covered in other parts of ISO 5667).
- Sampling chain of custody: Requires documentation of responsibility changes and traceability to maintain sample integrity from field to laboratory.
- Reagents and materials: Specifies use of analytical-grade reagents, shelf-life labelling, safe handling of hazardous preservatives and periodic checks (e.g., field blanks) to detect contamination.
- Containers and preparation: Guidance on container selection, cleaning and on-site filtration; Annex B provides container preparation techniques.
- Sample handling and preservation: General rules plus specific approaches for different analysis types (physical, chemical, hydrobiological, radiochemical); Annex A details preservation techniques.
- Storage times and validation: Tables (A.1–A.5) give default preservation conditions and maximum storage times per analyte; where methods differ, validated methods or ISO/TS 5667-25 guidance on validation take precedence.
- Transport, identification and reception: Requirements for transport conditions, sample labelling and laboratory receipt and storage procedures.
Practical applications and who uses it
ISO 5667-3:2024 is used by:
- Environmental and analytical laboratories setting sample handling SOPs
- Water utilities and wastewater treatment operators managing monitoring programmes
- Environmental consultants conducting field sampling and chain-of-custody documentation
- Regulatory agencies defining compliance sampling protocols
- Researchers planning field campaigns that require off-site analysis
Practical benefits include improved sample representativeness, reduced risk of analyte loss or contamination, consistent chain-of-custody records, and guidance for validating storage times to ensure reliable laboratory results.
Related standards
Keywords: ISO 5667-3:2024, water quality sampling, preservation and handling of water samples, sample preservation, chain of custody, storage times, water sample transport, laboratory sampling procedures.
