ISO/IEC 17025 Standard

The ISO/IEC 17025 standard (ISO/IEC 2005) has the title General requirements for the competence of testing and calibration laboratories and is the main standard to which analytical chemical laboratories are accredited. The word calibration in the title arises from the use of the standard to accredit bodies that calibrate instruments such as balances, electrical equipment, and utility meters. It must also be stressed that the standard is not written for analytical chemists, but for any measurement scientists. Therefore, the terminology tends to be general, and the emphasis is sometimes not clear for the chemist. However, the standard is wide ranging and covers a whole community of measurement scientists. 

Table 9.2 gives the subsections of section 4 of the ISO/IEC 17025 standard that deal with requirements for the management of the laboratory and the quality system that must be in place. 

Table 9.3 gives the subsections of section 5 of the ISO/IEC 17025 standard, which details technical requirements. References to testing and measurement and a focus on how tests should be performed and reported make this part of the standard unique and of value to analytical chemists. 

Agency, 2006). The scheme provides a framework within which environmental measurements can be made in accordance with the Agency s quality requirements and this includes documentation of the sampling and analytical procedures. Internationally, laboratories use the ISO/IEC 17025 Standard (British Standards, 2005) to implement a quality system aimed at improving their ability to produce valid results consistently. As the Standard is about competence, accreditation is simply formal recognition of a demonstration of that competence. 

ISO/IEC 17025 Standard, General Requirements for the Competence of Calibration and Testing Laboratories, ISO, Geneva, 1999. 

Measurement results and standards are internationally accepted via their demonstrated comparability and known quality. The test results of a food testing laboratory that is accredited to the ISO/IEC 17025 Standard should be recognized in other countries where laboratory performance is also assessed in accordance with this Standard. This is an aspect of the ILAC MRA [31]. The ISO/IEC 17025 Standard requires traceability to internationally accepted stated references together with their stated measurement uncertainties [22]. 

Uncertainties are a prerequisite for the comparability of analytical measurement results. The ISO/IEC 17025 standard requires traceability to internationally accepted stated references together with their stated measurement uncertainties. 

QC and QA are prerequisites to provide reliable analytical results to customers. Reliability is the key word in view of compliance of laboratories with the ISO/ IEC 17025 Standard. Particularly in the held of trace elements analysis, the IMEP process results in a representative picture of the measurement capabilities at a certain point in time on trace elements endorsed in respective EU and international legislation. The general observation is that the majority of laboratories perform very well or satisfactorily in IMEP, but some have serious problems and their claims do not correspond to their actual measurement capability, regardless of whether they are reference, authorized, or accredited laboratories. This emphasizes the fact that the use of IMEP as metrological quality tool is primarily to the benebt of laboratories. The correct application of metrological concepts such as traceability and uncertainty is the basis of providing high-quality and reliable... 

CRMs are an important tool for quality assurance and quality control in analytical laboratories. They are used for verification of accuracy and precision (i.e., reliability of the results of analysis, validation of analytical procedures, establishing measurement traceability, and calibration of measurement equipment). Use of CRMs is recommended by the ISO/IEC 17025 standard and therefore it is obligatory for those who wish to obtain and maintain accreditation of the laboratory. 

If new test methods combined with new instrumentation are introduced into a laboratory they should, self-evidently, be state of the art. On the other hand, if minor modifications occur in existing methods, obviously there will be less parameters to be validated. Therefore, the validation process should be defined and well-planned in all cases. The European co-operation for Accreditation of Laboratories (EAL) has provided general guidelines on certain issues related to the validation of test methods [8], According to paragraph 2.1.3, the required depth of the validation process depends on the maturity of the test method and the prevalence of its use. A standardised test method is exclusively defined by EAL. This interpretation can easily be applied to the medical laboratory field and has been discussed [9] in terms of additionally needed clarification in the new ISO/IEC 17025 standard [10]. Paragraph 5.4.5 states that the validation shall be as extensive as is necessary to meet the needs of the given application or field of application. 

The standard requires that where inspection, testing, and calibration services are conducted fay a supplier s laboratory facility, the laboratory shall comply with ISO/IEC 17025 including use of a laboratory scope. 

Medical laboratories have some specific needs and these are incorporated in ISO 15189 2003, Medical Laboratories - Particular Requirements for Quality and Competence [8]. The requirements of both ISO 9001 and ISO/IEC 17025 are incorporated within this Standard. It is a customized version of ISO/IEC 17025 for medical laboratories. In the UK, UKAS have designated Clinical Pathology Accreditation (UK) Ltd as the authoritative body to accredit against this Standard. 

This Standard was prepared specifically to cover medical laboratories. These laboratories carry out testing or examination of materials derived from the human body. Such studies are carried out for the purpose of providing information for the diagnosis, prevention and treatment of disease or assessment of the health of an individual. ISO 15189 covers a whole range of tests relating to clinical measurements, e.g. chemical and microbiological. This Standard is based on ISO 9001 and ISO/IEC 17025 and contains a correlation between the clauses and those in ISO 9001 and ISO/IEC 17025. 

The terminology used in this Standard is slightly different from the others in that it is appropriate for the particular discipline. For example, the term, referral laboratories in paragraph 4.5 of ISO 15189 is used in a slightly different sense to the comparable clause in ISO/IEC 17025. Included in this section are consultants who may provide a second opinion. If the referral laboratory is an external laboratory, to which samples are submitted for a supplementary or confirmatory examination procedure and report, it is much the same as a contract laboratory in ISO/IEC 17025. There is an extra Annex in this Standard which covers the ethics applicable to laboratory medicine. 

It can be seen that the GLP principles do cover similar requirements to both ISO 9001 and ISO/IEC 17025 but data generated solely under these standards would not generally satisfy the principles of GLP. This is mainly in the area of documentation. 

General Requirements for the Competence of Testing and Calibration Laboratories , ISO/IEC 17025 2005, International Organization for Standardization (ISO)/Intemational Electrotechnical Commission (IEC), Geneva, Switzerland, 2005. 

Method validation is defined in the international standard, ISO/IEC 17025 as, the confirmation by examination and provision of objective evidence that the particular requirements for a specific intended use are fulfilled. This means that a validated method, if used correctly, will produce results that will be suitable for the person making decisions based on them. This requires a detailed understanding of why the results are required and the quality of the result needed, i.e. its uncertainty. This is what determines the values that have to be achieved for the performance parameters. Method validation is a planned set of experiments to determine these values. The method performance parameters that are typically studied during method validation are selectivity, precision, bias, linearity working range, limit of detection, limit of quantitation, calibration and ruggedness. The validation process is illustrated in Figure 4.2. 

Some customers will require the results of the analysis to be interpreted or an opinion given, e.g. does the discharged water from the factory comply with the current legislation ) or how many cigarettes can be made from 2 kg of cannabis leaf There is now provision for this aspect of the work of an analyst to be included in the scope of accreditation of the laboratory to the Standard ISO/IEC 17025 2005 [1]. It is important to be clear about what is meant by Opinions and Interpretations. In the context of this book, it is the subjective expression given that is based on results, academic or scientific knowledge and experience gained over a period of time. 

As mentioned previously, it is possible to include opinions and interpretations within the scope of accreditation. It should be realized that the opinions and interpretations themselves are not accredited. This accreditation is only given if the work is already accredited to ISO/IEC 17025 [1]. What is required by the Standard is evidence of the procedure used by the laboratory to authorize an individual to give an opinion or interpretation. This means there has to be a procedure within the management system of the laboratory that sets out the criteria upon which the quality of the person giving the opinion is assessed. This may be split into two parts, namely the criteria for assessing competence and the criteria for assessing experience. 

The management standards available have already been introduced and their general features highlighted in Chapter 2. Some of the more specific components of the Standards will be covered in this chapter. For general chemical laboratories, the two Standards that are most frequently encountered are ISO/IEC 17025 and GLP and so these will be covered more fully in the following sections. 

A laboratory is free to decide which scheme is most appropriate for its own circumstances. Laboratories entering the audit process for the first time may prefer to carry out an initial complete audit to establish if problems exist, followed, after an appropriate interval, by a rolling programme to maintain standards. When auditing to ISO/IEC 17025, the auditor should plan to witness at least one method being carried out. 

Examples of Quality Audit report forms are shown in Tables 9.5 and 9.6 at the end of this chapter. Table 9.5 shows Report Form 1 which includes a record of what has been examined, so that subsequent audits can examine other aspects of the laboratory s operations. Note that when improvement actions are required, the form records not only what needs to be done, but also by when it must be completed, as shown in Table 9.6 (Report Form 2). The form is signed by the auditor and the responsible person from the area being audited. In the UK, the accreditation body UKAS refers to the corrective action as improvement action . This further emphasizes the continual improvement aspect of the ISO/IEC 17025 and ISO 9001 Standards. The examples shown in Tables 9.5 and 9.6 will probably have to be modified to meet a laboratory s particular requirements. It should also be remembered that both report forms should indicate (usually as a footer or header) the title of the document, its issue date, issue number, who authorized the document, page number and total number of pages. 

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