Overview
ISO 7023:1983, "Packaging - Sacks - Method of sampling empty sacks for testing", defines a standardized, two-stage method to obtain representative samples of empty sacks for laboratory testing and quality assessment. The procedure is applicable to all types of empty sacks and is intended to assess the average quality of a consignment (not for production process control). The standard describes random selection rules, unit and element definitions, use of sampling tables, handling precautions, re-sampling procedures and required test-report information.
Key topics and requirements
- Scope and applicability: Sampling to assess average lot quality; not intended for production control. The sample represents only the sacks available for sampling.
- Two-stage sampling principle:
- Stage 1 - selection of a prescribed number of units from the lot (examples of units: bundles, bales, pallet loads, container loads).
- Stage 2 - selection of sacks either directly from each selected unit or, where units are subdivided, selection of elements (elements cannot be individual sacks) and then sacks from those elements.
- Random selection: Each part of the whole must have an equal chance of being selected.
- Sampling tables: The standard provides tables (referenced from ISO 186 and ISO 3951) to determine the number of units, elements and sacks to select based on lot size.
- Definitions: Clear definitions for lot, unit and element to ensure consistent sampling.
- Precautions and handling: Selected sacks must be kept and handled to avoid permanent changes before testing.
- Marking and traceability: Each selected sack must carry identification marks proving origin.
- Re-sampling rules: Procedures for re-sampling after accidental loss/damage or other reasons; re-sampling should follow the same specification as closely as possible.
- Test report content: The report must include a reference to ISO 7023, purchaser/vendor names and addresses, date/place of sampling, lot description, numbers of units/elements/sacks (in lot and selected), identification references, circumstances affecting results, sampler signature and any deviations from the standard.
Applications and users
- Quality assurance and compliance testing for manufacturers, converters and traders of sacks (paper, woven, plastic, multiwall).
- Purchase inspection by buyers, inspection bodies and testing laboratories to verify consignment conformity.
- Contractual and dispute-resolution sampling where standardized, reproducible methods are required.
- Logistics and packaging engineers needing consistent sampling protocols for lot-based quality assessment.
Related standards
- ISO 186 (sampling guidance referenced for unit selection)
- ISO 3951 (sampling procedures and charts for inspection by variables)
- ISO/TC 122 (Packaging - technical committee developing packaging standards)
Keywords: ISO 7023:1983, empty sacks sampling, packaging standard, sacks sampling method, quality control sampling, sampling for testing.
