EA-4/23:2026 — opinions and interpretations in accredited laboratory reports: a new definition without decision rules or numerical risk, an unbroken chain of accreditation for external services, and acceptable and unacceptable examples
EA published EA-4/23 INF:2026 (rev03 of 26 January 2026, approved on 22 January, applicable from publication) on the assessment and accreditation of opinions and interpretations under EN ISO/IEC 17025:2017 (clauses 6.2.6 and 7.8.7). It aims to harmonise the approach of accreditation bodies and the way opinions and interpretations are shown to customers in scopes of accreditation.
- Definition: opinions and interpretations are the outcome of a process in which test or calibration results are extended beyond the scope of the result or the item, using knowledge and professional judgement. They may not include numerical use of measurement uncertainty, a decision rule or a numerical level of risk, although uncertainty must be understood and considered. A statement of conformity based on a decision rule is not an opinion or interpretation. The 2019 edition defined it in general terms as extending the applicability of a result.
- New principles: accredited opinions and interpretations require an unbroken chain of accreditation — if an external provider performed part of the testing, it must have done so as an accredited activity; opinions and interpretations cannot be accredited as a stand-alone activity. A laboratory accredited only for sampling may give them if it demonstrates competence in the testing. For forensic science EA refers to ISO 21043-4 and -5.
- The laboratory documents the scope of such services, contract review, competence criteria, qualification records, internal audits and consistency between staff; staff are expected, among other things, to show documented sector experience, CPD and examples of past work. Opinions and interpretations must not be used as a substitute for product certification.
- Acceptable examples: a forecast of a field’s suitability based on soil nitrogen and microbiological activity, extended application of a door fire classification under CEN/TS 15117 and EN 15725:2023, advice when calibrating a thermometer. Unacceptable: recommending certification based on one bolt, extending paint results to other batches or brands, an opinion after a method used outside its scope. Appendix B shows a scope of accreditation with an “opinions and interpretations” column.