Accreditation and Quality Assurance最新文献

Lead exposure is a well-known health concern, affecting children worldwide. We aim to assess children’s blood lead levels (BLLs), and the association of risk factors with elevated BLL in children since the phase-out of leaded gasoline. We enrolled 8085 outpatient children to assess their blood lead levels, and the associations with social-demographic factors. Social-demographic information was obtained by using questionnaires. Multivariable linear and logistic regression models were performed to explore the associations between social-demographic factors and elevated BLLs. The geometric mean BLL was 15.96 μg/L. The prevalence rates of elevated BLLs (≧ 100 μg/L and ≧ 50 μg/L) were 2.0 % and 10.9 %, respectively. BLLs in boys were higher than that in girls (P < 0.001). Girls had a lower risk of BLLs above 50 μg/L than boys (OR = 0.83, 95 % CI 0.71–0.96). Father’s occupation as a skilled laborer or professional worker and living in the suburbs significantly contributed to the elevated BLLs ( ≧ 50 μg/L), with the ORs of 1.39 (1.06–1.81), 1.33 (1.01–1.75) and 1.24 (1.02–1.50), respectively. Our results suggested that children who lived in suburbs and whose fathers were skilled laborers and professional workers were more likely to have BLLs above 50 μg/L.

From 2008 to 2020, the Ministry of Food and Drug Safety (MFDS) and the Korea Research Institute of Standards and Science (KRISS) jointly conducted a proficiency testing (PT) program for the analysis of pesticide residues in kimchi cabbage and ginseng powder. This collaborative effort marked a significant milestone in South Korea, being the first instance of employing metrologically traceable assigned values, determined via isotope dilution mass spectrometry (IDMS), in PT programs. The focus was on a selective range of pesticides, including diazinon, chlorpyrifos, p,p’-DDE, γ-HCH (lindane), α-endosulfan, and β-endosulfan. Each biennial PT program centered on two of these pesticides with participating laboratories reporting their mass fractions in provided samples. PT samples were prepared meticulously prepared in powder form by KRISS, ensuring homogeneity and stability, integral for the accuracy of the testing. The paper elaborates on the intricate processes involved in PT sample preparation and the rigorous assignment of values. To evaluate laboratory proficiency, the Horwitz equation was utilized as a general mode to set for standard deviations in proficiency assessment. An in-depth review of seven PT programs conducted over this period demonstrates the significant role these programs played in advancing the measurement competencies of laboratories, underscoring the novelty and impact of this long-term collaborative effort.

For a laboratory following the ISO/IEC 17025:2017 standard, establishing a calibration programme is a requirement as per Clause 6.4.7. Clause 6.4.6. of the ISO/IEC 17025:2017 standard states that measuring equipment shall be calibrated when its measurement accuracy or measurement uncertainty affects the validity of the test results and/or when establishment of the metrological traceability of the test results is required. Equipment commonly used in a conventional food microbiology laboratory include biosafety cabinets or laminar flow cabinets, balances, diluters, homogenizers or blenders or mixers, pH meters, autoclaves, incubators, refrigerators, freezers, deep freezers, thermostatically controlled water baths, sterilizing ovens, temperature-monitoring devices such as thermometers, micropipettes, dispensers, vortex mixers, centrifuges, hot plates, and stop watches. The standard ISO 7218:2007/Amd 1:2013 provides guidance on which equipment requires calibration but sometimes, the accreditation body establishes more stringent guidelines which the conformity assessment body needs to follow. So, equipment that requires calibration may differ between conventional food microbiology laboratories accredited by different accreditation bodies. In this practitioner’s report, the author discusses the points a conventional food microbiology laboratory needs to consider when establishing a calibration programme.

The number of reference materials (RMs), including certified reference materials (CRMs) characterized for qualitative properties, has steadily increased in recent years. In response, the Technical Committee for Reference Materials of the International Organization for Standardization, ISO/TC 334, developed ISO 33406 to provide guidance to reference material producers (RMPs) on producing qualitative RMs. ISO 33406 builds on the general requirements in ISO 17034:2016 for RMP competence and offers specific guidance on value assignment, assessment of homogeneity and stability, statement of metrological traceability, and measurement uncertainty evaluation for RMs with qualitative property values.

According to clause 7.2.1.5, it is essential that a laboratory that follows the ISO/IEC 17025:2017 standard verifies standard methods or validated alternative methods before it starts using them. In 2021, the International Standard Organization published the ISO 16140-3:2021 standard. This standard provides guidelines for verification of reference methods and validated alternative methods in a single food microbiology laboratory. By using the guidelines provided in the standard, we performed the method verification of Compact Dry BC, a ready-to-use media for quantification of Bacillus cereus in foods or raw materials. This Compact Dry BC method was validated by MicroVal according to the ISO 16140-2:2016 standard and revealed to be at least equivalent to the reference method “ISO 7932: 2004—Microbiology of food and animal feeding stuffs—Horizontal method for the enumeration of presumptive Bacillus cereus—Colony count technique at 30 °C”. For implementation verification, the laboratory selected dried infant formula samples, while for food item verification, the laboratory chose dried infant formula, canned fish, breakfast cereal, sliced meat and pie samples. Intralaboratory reproducibility standard deviation (S_IR) obtained by the laboratory was 0.055 log₁₀ CFU, while the acceptable S_IR is ≤ 0.341 log₁₀ CFU. Estimated bias (eBias) for dried infant formula, canned fish, breakfast cereal, sliced meat and pie samples were also found to be ≤ 0.5 log₁₀ CFU for low, medium, and high inoculum levels. Therefore, as per the criteria set by the ISO 16140-3:2021 standard, the Compact Dry BC method is suitable to use in our laboratory for enumeration of presumptive B. cereus in a broad range of food.

The globalisation of trade and environmental and health requirements, supported by the physical–chemical characterisation of relevant items, have promoted relevant evolutions on how test laboratories report results from their analysis. The relevance of reporting measurement results from the characterisation of these items with the measurement uncertainty is unquestionable to guarantee determinations are adequately uncertain and the objective interpretation of analytical information. The latest edition of the ISO/IEC 17025 standard, which supports the International Accreditation of test laboratories, even mentions the need to manage the impact of measurement uncertainty in the risk of false conformity assessments. Some accreditation bodies have considered this novelty and the reiteration that measurement results should be reported with the measurement uncertainty to make reporting the measurement uncertainty mandatory. This correct interpretation of the accreditation standard and society's expectations regarding the role of laboratories in the management of the most relevant interests of the community should be generalised.

This paper details the activities carried out by the Chemical Metrology Department of LATU in the development of a national proficiency testing (PT) scheme aimed at assessing the competence of laboratories in air quality parameters analysis. In this PT scheme, environmental monitoring laboratories were required to determine the concentration of elements in quartz-grade microfiber filters and impinger solutions, as well as to determine the amount fraction of a carbon monoxide in nitrogen gas mixture, within the range of (800 to 1700) µmol/mol. The focus of the present paper is mainly devoted to the second phase of the test, which addresses the preparation of the gas cylinder distributed to each participant for measurement. A detailed description of this stage is provided, along with the evaluation of the results reported by participating laboratories. This test provided an effective tool for participating laboratories to assess their national technical competence, using their preferred analysis methods.

Soil certified reference material (CRM), UME EnvCRM 03 was produced by a collaborative approach among national metrology institutes, designated institutes and university research laboratories within the scope of the EMPIR project: Matrix Reference Materials for Environmental Analysis. This paper presents the sampling and processing methodology, homogeneity, stability, characterization campaign, the assignment of property values and their associated uncertainties in compliance with ISO 17034:2016. The material processing methodology involves blending a natural soil sample with a contaminated soil sample obtained by spiking elemental solutions for 8 elements (Cd, Co, Cu, Hg, Ni, Pb, Sb and Zn) to reach the level of warning risk monitoring values specified for metals and metalloids of soils in Europe. Comparative homogeneity and stability test data were obtained by two different institutes, ensuring the reliability and back up of the data. The certified values and associated expanded uncertainties for the total mass fractions of thirteen elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, V and Zn) are established. The developed CRM can be used for the development and validation of measurement procedures for the determination of the total mass fractions of elements in soil and also for quality control/assurance purposes. The developed CRM is the first example of a soil material originating from Türkiye.

Internal auditing is an important part of the ISO/IEC 17025:2017 standard. Clause 8.8 of the ISO/IEC 17025:2017 standard describes the requirements that the testing and calibration laboratories need to follow in the area of internal auditing. However, the standard does not describe which technique to use when conducting internal audits and the ISO 19011:2018 standard (Guidelines for Auditing Management Systems) only mentions the audit methods that can be used by an auditor, lacking practical aspects. Based on the internal auditing technique used, non-conformities that are present may or may not be detected. For example, technical competency of an analyst cannot be completely ascertained by just thoroughly reviewing the related documents such as training records. Therefore, it is important that internal auditors utilize appropriate techniques during an internal audit for it to be an effective one. Different internal auditors use different techniques during the audit. The commonest way internal auditors use is to develop a checklist (usually the one used by the accreditation body to which the laboratory is affiliated) for auditing the compliance to the ISO/IEC 17025:2017 management system and witnessing the technical competence of the technical staff. The aim of this article is to share the techniques utilized by the author during the internal auditing of ISO/IEC 17025:2017 accredited testing laboratories.