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The ISO/IEC 17025:2018 standard sets requirements for laboratories on two levels simultaneously: the organisational level – concerning how the laboratory is managed – and the technical level – concerning the technical competence required to carry out tests or calibrations. Both levels are of equal importance and both are verified during the assessment by the Polish Centre for Accreditation. Below, we discuss the areas which, in practice, pose the greatest difficulties for laboratories and are assessed most thoroughly by PCA assessors.
Staff competence – the standard requires that all personnel carrying out testing or calibration have documented technical competence – appropriate education, training and experience in the activities they perform. The laboratory must maintain documented records of each employee’s competence, and must regularly review and update these records. It is particularly challenging to demonstrate staff competence in the use of non-standardised methods or in-house developed methods – these must be validated and documented.
Measuring equipment and measurement traceability – ISO/IEC 17025:2018 places very strong emphasis on measurement traceability – the requirement that measurement results be linked to SI units via an unbroken chain of calibrations with documented measurement uncertainty. In practice, this means that all measuring equipment affecting the test result must be calibrated by bodies with the appropriate competence, and the calibration results must be documented and analysed in terms of their impact on the reliability of test results.
Test methods and their validation – a laboratory may use standardised methods (ISO, EN, PN standards), in-house standards or non-standardised methods. Each method must be described in a documented procedure. Non-standardised methods and methods developed by the laboratory require validation – documented confirmation that the method is suitable for its intended use. Even standardised methods require verification – confirmation that the laboratory is able to apply them correctly under its own conditions. The results of validation and verification must be retained as records.
Premises and environmental conditions – the standard requires that environmental conditions in laboratories be monitored, controlled and documented to the extent that they affect test results. This applies to temperature, humidity, air purity, vibrations, noise and lighting – depending on the specific nature of the tests carried out. Deviations from the required conditions must be recorded and assessed for their impact on the validity of the results.
Documentation under ISO/IEC 17025 is more extensive and specific than in typical quality management systems – and constitutes one of the key areas of assessment during a PCA audit. The standard distinguishes between two layers of documentation, which must be consistent and interlinked.
System documentation comprises documents describing how the laboratory is managed: quality policy and objectives, general management procedures (internal audits, corrective actions, complaint handling, equipment supervision, procurement), procedures relating to impartiality and confidentiality, and records confirming compliance with these requirements. In the 2018 edition, the standard permits two variants of the management system – one based on the requirements of clauses 8.2–8.9 and one compliant with ISO 9001 – which gives laboratories some flexibility in choosing their approach.
Technical documentation is specific to ISO/IEC 17025 and has no equivalent in general management system standards. It includes: documented test or calibration procedures for each accredited method, records of method validation and verification, calibration certificates for measuring equipment with documentation of measurement uncertainty, sampling procedures (where applicable), as well as the estimation and documentation of measurement uncertainty for each type of test or calibration. The latter requirement in particular – the measurement uncertainty budget – is an area where laboratories most frequently have shortcomings during the initial PCA assessment.
The reporting of results is another element strictly regulated by the standard. Test reports and calibration certificates must contain precisely defined information, including unambiguous identification of the method, results with units, information on measurement uncertainty and – where applicable – a statement of compliance with the requirements or specification. Any change to the content of a report after its issue requires a documented procedure.
The 2018 version of ISO/IEC 17025 significantly expanded the requirements concerning laboratory impartiality compared with the previous edition. This is one of the areas that distinguishes the laboratory standard from typical management system standards.
The laboratory must identify threats to its impartiality – both internal (e.g. financial pressure to achieve specific results, conflicts of interest amongst staff) and external (e.g. the influence of the owner, clients or other interested parties on test results). For each identified threat, documented measures must be implemented to eliminate or minimise the risk. The laboratory’s management must commit to impartiality and actively manage it – the declaration of impartiality is a document verified during every PCA assessment. Confidentiality requirements include the protection of information obtained during the performance of laboratory activities, including client data, test results and any information relating to samples. The laboratory must have documented procedures in place to ensure confidentiality, and staff must be familiar with these and obliged to comply with them. These requirements are of particular importance for laboratories working on behalf of the courts, regulatory bodies and industrial clients, for whom the confidentiality of results is a prerequisite for commissioning tests from an external laboratory. A well-prepared management system and comprehensive documentation make it much easier to pass a PCA assessment. Find out how we support laboratories in implementing ISO/IEC 17025.
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