Taking laboratory uncertainties into account in the Hampel estimator

Accreditation and Quality Assurance - According to ISO/IEC 17025:2017, testing and calibration laboratories should apply procedures for estimating measurement uncertainty. It would thus make sense...     

Can single-operator laboratories comply with all of the requirements of ISO/IEC 17025:2005?

ISO/IEC 17025:2005 states that its requirements are “applicable to all laboratories regardless of the number of personnel” and would therefore include single-operator laboratories. However, there are reservations as to whether these laboratories can comply with all of the requirements without jeopardizing independence of judgement and impartiality. Similarly, there are some requirements of ISO/IEC 17025:2005 including staff supervision, internal communication processes and appointment of deputies that are considered unlikely to apply to a single-operator laboratory. The ISO/IEC 17025:2005 is widely used as the international standard of quality assurance by which accreditation bodies assess the competency of testing and calibration laboratories. There does, however, appear to exist, disagreement amongst accreditation experts when considering single-operator laboratories. Some accreditation bodies accredit single-operator laboratories, whilst others require additional human resources prior to granting accreditation. This discrepancy leads to unfair competition amongst laboratories as a single-operator laboratory by definition needs less resources (both human and financial) to achieve and maintain accreditation, compared with a laboratory where additional human resources need to be sought prior to and in order to maintain accreditation. The ISO/IEC 17025:2005 is in the process of being revised, and this is an opportune moment to address the issues aforementioned with the aim of removing ambiguity and enhancing clarity. In addition, the hope is to assist the accreditation bodies themselves to adopt a consensus approach when granting accreditation towards single-operator laboratories.     

The third edition of ISO Guide 34: what were the drivers for the revision and what is new?

After the International Laboratory Accreditation Cooperation (ILAC) had taken in 2004, the resolution to conduct accreditation of producers of reference materials according to ISO Guide 34 ‘General requirements for the competence of reference material producers’ in combination with ISO/IEC 17025 ‘General requirements for the competence of testing and calibration laboratories’, ISO/REMCO, the ISO Committee on Reference Materials, decided in 2005 to revise ISO Guide 34 to align it closer with ISO/IEC 17025 and to clarify certain issues for accreditors and producers seeking accreditation without adding new requirements. Moreover, the publication in 2007 of ISO/IEC Guide 99 ‘International vocabulary of metrology—Basic and general concepts and associated terms (VIM)’ triggered additional adaptations of the guide.     

Implementation of ISO/IEC 17025 Standard for the accreditation of analytical laboratories in Russia

The history since 1992 and the current state of affairs of the Russian Accreditation system for analytical laboratories are described. Some national characteristics of the implementation of the ISO/IEC 17025 Standard in Russia are considered. The elucidation of some ISO/IEC 17025 Standard prepositions is presented to facilitate implementation of the Standard by accreditation bodies and analytical laboratories claiming accreditation.     

Data integrity: requirements set in the accreditation standards

Accreditation and Quality Assurance - The requirements for the competence of laboratories are described in two standards, namely ISO/IEC 17025 and ISO 15189. The former applies to all laboratories...     

Current best practice for traceability in testing laboratories,when certified reference materials are unavailable

Since the implementation of ISO/IEC 17025 in 2002, all accredited laboratories (at the least) need to establish traceability in all their tests and calibration methods. Traceabilty, though well understood in the calibration field (through an unbroken chain of comparisons to the International System of Units —SI), is less straight forward and not so well understood in the testing laboratories. Traceability in analytical and biological testing is found through the use of reference materials, and the validated steps of a test method. This article describes the possibilities to comply with the traceability requirement of ISO/IEC 17025 in testing laboratories , when certified reference materials are unavailable.Presented at the Second International Conference on Metrology—Trends and Applications in Calibration and Testing Laboratories, 4–6 November, 2003, Eilat, Israel     

Experience of the implementation of EA-4/18

Accreditation and Quality Assurance - The standard ISO/IEC 17025 (sub-clause 5.9) requires that the validity of tests results is monitored by laboratories and one of the tools that can be used is...     

Certification of reference materials and accreditation of reference material producers: Questionable terminology leads to confusion

In the view of the Deutscher Kalibrierdienst (DKD) , a certifying body for reference materials can be considered to be a calibration laboratory. Therefore, accreditation of calibration laboratories in accordance with ISO/IEC 17025 is the most appropriate way to establish confidence in certificates for reference materials. If necessary, the criteria of ISO/IEC 17025 can be tailored to specific cases. There is no need to provide any new kind of reference-material specific accreditation. However, in view of the variety of reference materials and the practice existing in other countries, accreditation of testing laboratories and product certification bodies may optionally be acceptable as long as the same stringent principles with respect to traceability and measurement uncertainty are applied. Such accreditations but not accreditations of reference material producers (ISO Guide 34) are also covered by existing international mutual recognition arrangements (MRA).     

Accreditation of reference material producers: Let's get it right!

The accreditation of testing and calibration laboratories to ISO/IEC 17025 is increasingly calling for the accreditation of reference material (RM) producers. Two international guides, ISO Guide 34 (2000) " General requirements for the competence of reference material producers" issued by the ISO Committee on Reference Materials and ILAC-G 12 " Guidelines for the requirements for the competence of reference material producers" issued by the International Laboratory Accreditation Cooperation (ILAC), are already in use for this purpose. Recently however initiatives have been launched to accredit RM producers to ISO 17025 as calibration laboratories and it has been suggested that a combination of ISO/IEC 17025 " General requirements for the competence of testing and calibration laboratories" and ISO Guide 34 may be the best option. This publication is an expression of the position of the ISO Committee on Reference Materials (ISO/REMCO) on the standards and guides currently in use in the accreditation of RM producers. The paper discusses the advantages and disadvantages of these standards and guides from the perspective of benefit to RM producers and RM users. In conclusion, the use of ISO Guide 34 alone or in combination with ILAC-G 12 is the preferred system for the accreditation of RM producers. Therefore ISO/REMCO strongly encourages all accreditation bodies to adopt ISO Guide 34.     

Accrediting PT/EQA providers to ISO/IEC 17043

After many years and having several different attempts for the accreditation of proficiency testing provider (PT provider), there is finally one stand-alone standard defining the requirements for the competence of PT providers and therefore an internationally harmonised basis for the accreditation of proficiency test providers. Since February 2010, the ISO/IEC 17043:2010 has replaced ISO/IEC Guide 43:1997 and ILAC G 13:2007. The philosophy of the standard about subcontracting work is different to this of the standards mostly used for accreditation like ISO/IEC 17025:2005 or ISO/IEC 17020:2004, etc. Besides the planning of the proficiency tests (PT), the performance evaluation and the authorisation of the PT reports the ISO/IEC 17043:2010 allows subcontracting for the rest of the work when providing PTs. This is a challenge for the assessors to judge about the competence of a PT provider. In numerous paragraphs, the standard sets very detailed requirements. Nevertheless, there is room for interpretation. For these cases, for example, contracts for subcontractors, procedure for the advisory board, minimum requirements for PT certificates, etc., some proposals are given to enable harmonised approach for the assessment of PT providers.     

Achieving traceability in chemical measurement—a metrological approach to proficiency testing

ISO/IEC 17025 requires that testing laboratories establish the traceability of their measurements, preferably to the SI units of measurement. The responsibility for establishing traceability lies with each individual laboratory and must be achieved by following a metrological approach.The results of measurements made in such a way are traceable to the standards used in method validation and to the calibration standards used during the measurement process. If these standards are traceable to SI then the measurements will also be traceable to SI.Participation in appropriate proficiency studies (an ISO/IEC 17025 requirement) enables laboratories to demonstrate the comparability of their measurements. If the materials used for the studies have traceable assigned values, then proficiency testing also provides information about measurement accuracy and confirms, or otherwise, that appropriate traceability has been established. This paper will report on a new approach for the establishment of traceable assigned values for chemical testing proficiency studies. The work is conducted at a "fit for purpose" level of measurement uncertainty, with costs contained at a level similar to previous "consensus" based proficiency studies. By establishing traceable assigned values in a cost effective way, NARL aims to demonstrate the added value of the metrological approach to participant laboratories.     

Accreditation of calibration laboratories to normative documents: diversity or standardization

Calibration of measuring equipment is conducted by following some normative or applicable documents such as standards, manufacturer manuals and instructions, technical orders issued by defense organizations, or scientific papers. An accreditation body provides its recognition to the calibration laboratories by evaluating their technical competence and their compliance with the quality requirements of ISO/IEC 17025. The accreditation body must have defined criteria in order to evaluate different calibration methods which should ensure that the laboratories are performing the calibration in a technically competent manner when they are fully or even only partially based on the relevant reference documents. A discussion with different points of view about choosing the criteria, as well as the Israel Laboratory Accreditation Authority (ISRAC) policy on this issue, are presented.Presented at the 2nd International Conference on Metrology – Trends and Applications in Calibration and Testing Laboratories, November 4–6, 2003, Eilat, Israel.     

Measurement uncertainty—policy and guidance documents issued by accreditation bodies

ISO/IEC 17025 contains general requirements for the competence of calibration and testing laboratories, including those for the evaluation and reporting of measurement uncertainty. Some accreditation bodies have issued additional guidance documents and regulations related to uncertainty, five of which are briefly commented on here.Presented at Roche Diagnostics' Workshop on in vitro diagnostics directive. A Nordic event about the implication of traceability and uncertainty in practice, Helsinki, February 13, 2003.     

The Operational System of National Accreditation of Laboratories in China

This document gives a brief introduction to CNACL (China National Accreditation Committee for Laboratories). Laboratory accreditation in China is integrally administrated by the China State Bureau of Quality and Technical Supervision, a government administrative department of China State Council, which authorizes CNACL to implement Chinese laboratory accreditation activities. CNACL was established on September 20, 1994. It is a full member of both ILAC (International Laboratory Accreditation Cooperation), and APLAC (Asia Pacific laboratory Accreditation Cooperation), and signed the APLAC MRA (Mutual Recognition Arrangement) in New Delhi, India on December 3, 1999. CNACL carries out laboratory accreditation activities in full compliance with international general criteria. Its operation complies with ISO/IEC Guide 58 (1993), ISO/IEC 17025 (1999), ISO/IEC Guide 43 (1997) and other international standards.     

Accreditation of GMO detection laboratories: Improving the reliability of GMO detection

Reliable and efficient methods for detecting genetically modified organisms (GMOs) are essential for establishing an effective system for traceability all along the supply chain from seed producers to final consumers. The latter is especially meaningful in European Union and other countries where strict legislations on GMOs were set up. Performance of the methods used in laboratories around the world should be uniform, in order to obtain reliable and comparable results. Accreditation is a suitable system for harmonising procedures in each testing laboratory. In this paper, key elements for the accreditation of molecular biology methods for GMO detection according to ISO/IEC 17025 are described. The procedures described are also valuable for the accreditation of molecular methods for all laboratory diagnostics where qualitative and quantitative characterisation of nucleic acids is needed.     

Document control: status of calibration/test certificate

The ISO/IEC 17025 standard requires that all documents that form part of the management system of the organization must be controlled. However, as customary, the certificates issued from testing or calibration laboratories do no bear any unique identity mark/number similar to other documents to announce control over the document. This leaves enough room for doubt to many in treating this document at par with other management system documentation. Some auditors had raised this question during accreditation visits.     

Proficiency testing program for the determination of total arsenic, cadmium, and lead in seawater shrimp

The proficiency testing (PT) program for 97 worldwide laboratories for determining total arsenic, cadmium, and lead in seawater shrimp under the auspices of the Asia-Pacific Laboratory Accreditation Cooperation (APLAC) is discussed. The program is one of the APLAC PT series whose primary purposes are to establish mutual agreement on the equivalence of the operation of APLAC member laboratories and to take corrective actions if testing deficiencies are identified. Pooled data for Cd and Pb were normally distributed with interlaboratory variations of 21.9 and 34.8%, respectively. The corresponding consensus mean values estimated by robust statistics were in good agreement with those obtained in the homogeneity tests. However, a bimodal distribution was observed from the determination of total As, in which 14 out of 74 participants reported much smaller values (0.482-6.4 mg/kg) as compared with the mean values of 60.9 mg/kg in the homogeneity test. The use of consensus mean is known to have significant deviation from the true value in bi- or multimodal distribution. Therefore, the mode value, a better estimate of central tendency, was chosen to assess participants' performance for total As. Estimates of the overall uncertainty from participants varied in this program, and some were recommended to acquire more comprehensive exposure toward important criteria as stipulated in ISO/IEC 17025.     

Quality assurance in analytical laboratories engaged in research and development activities

 Research and development activities are carried out by various types of laboratories that are not the typical testing and calibration laboratories for which the ISO/IEC 17025 is the quality assurance implementation reference. In this paper, such laboratories engaged in R&D activities are classified and different approaches they can adopt with a view to implementing a quality system that are suited to their characteristics and the type of work they conduct are proposed. These approaches take account of existing standards for the certification/accreditation of laboratories and of guides on quality assurance for non-routine analytical laboratories. Received: 11 July 2002 Accepted: 29 November 2002 Presented at Analytica Conference, 23–26 April 2002, Munich, Germany Correspondence to M. Valcárcel     

News from CEN/BT/WG 122 uncertainty and EA expert group on uncertainty

Since the publication in 2000 of the standard ISO/IEC 17025 "General requirements for the competence of testing and calibration laboratories", the concept of uncertainty of measurement or test results seems to be a key issue for laboratories and their clients. Two working groups are trying to implement this concept in testing activities. The CEN/BT/WG122 has proposed to the technical bureau of CEN a series of recommendations on how to introduce this concept in European standards and the EA expert group on uncertainty has prepared a guidance document in order to help the testing community in uncertainty evaluation. The objective of this paper is to report the current situation of these two groups.