Inter American Accreditation Cooperation

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1 CLASSIFICATION This document is classified as an IAAC Guidance Document. AUTHORIZATION Issue Nº: 01 Prepared by: Laboratories Subcommittee Date: January 2013 Revision Nº: 00 Approved by: Executive Committee Issue Date: March 1, 2013 Application Date: Immediate Document number: IAAC GD 010/13 Inquiries: IAAC Secretariat Telephone: +52 (55) Fax: +52 (55) AVAILABILITY Copies of this document in English and Spanish are available at the IAAC Secretariat and on the IAAC web site. COPYRIGHT IAAC holds the copyright of this document and it may not be copied for resale. Original: English Date of Issue: March 1, 2013 IAAC AD 010/13 Page 1 of 6

2 1. Objective: To provide a guide for laboratories and accreditation bodies about minimal considerations to be taken into account during the accreditation of sampling activities in testing laboratories. 2. Scope: This document is aimed for its application in the accreditation of sampling for testing laboratories. 3. Introduction: Sampling and sample taking is an important part of the conformity assessment process. Sampling may significantly influence the results of this process. This is why it is necessary to establish criteria for the accreditation of sampling by accreditation bodies. It is recommended that accreditation bodies take into account the factors herein documented. However some criteria herein defined are not relevant for all types of sampling. 4. Definitions: Sampling: Sampling is a defined procedure through which a portion of a substance, a material or a product is taken in order to provide a representative sample of the total, for testing. Sampling may also be required by the appropriate specification according to which the substance, material or product will be tested. In some cases (for example, in forensics analysis), the sample may not be representative, but determined by its availability. It is convenient that sampling procedures describe the sampling plan, the selection, extraction and preparation of one or more samples from a substance, a material or a product in order to obtain the required information. (ISO/IEC 17025:2005: General requirements for the competence of testing and calibration laboratories) Sample Taking: process to obtain the sample to test with the purpose of ensuring the validity of the result, avoiding mistakes due to contamination, degradation, etc of the samples to be tested. The taking of samples by itself does not allow to extrapolate the results of the sample to the item sampled (that one from where the samples have been taken). (ENAC: NT-43 Rev 1 September 2008 Testing Laboratories: Sampling and Sample Taking Accreditation) Sampling Plan: number, location, time and nature of samples to take. 5. Basic Criteria for Accreditation of Sampling for Testing Laboratories under the Standard ISO/IEC If accredited under ISO/IEC basic requirements shall be followed for sampling as follows: ISO/IEC 17025, section 5.7 states The laboratory shall have a sampling plan and procedures for sampling when it Date of Issue: March 1, 2013 IAAC AD 010/13 Page 2 of 6

3 carries out sampling of substances, materials or products for subsequent testing or calibration. The sampling plan as well as the sampling procedure shall be available at the location where sampling is undertaken. Sampling plans shall, whenever reasonable, be based on appropriate statistical methods. The sampling process shall address the factors to be controlled to ensure the validity of the test and calibration results Where the customer requires deviations, additions or exclusions from the documented sampling procedure, these shall be recorded in detail with the appropriate sampling data and shall be included in all documents containing test and/or calibration results, and shall be communicated to the appropriate personnel The laboratory shall have procedures for recording relevant data and operations relating to sampling that forms part of the testing or calibration that is undertaken. These records shall include the sampling procedure used, the identification of the sampler, environmental conditions (if relevant) and diagrams or other equivalent means to identify the sampling location as necessary and, if appropriate, the statistics the sampling procedures are based upon. Several other clauses of ISO/IEC contain requirements about sampling: , 5.2.5, 5.3.1, 5.4.1, 5.4.2, , 5.5.1, 5.5.2, 5.5.6, 5.6.1, , 5.8.4, (h), and SPECIFIC GUIDANCE: 6.1 When is it recommended to Accredit Sampling: a. For testing used for the compliance with a regulation or whenever it is requested by a regulatory authority. b. If the standardized testing method incorporates it within the procedure. c. If requested by the laboratory. 6.2 Description of Sampling in the Scope of Accreditation: a) Sampling is normally accredited as part of testing for which the accreditation is requested. b) For those cases of sampling isolated activities, the Accreditation Body should define its policy for the accreditation of these activities. c) The scope of accreditation should identify, Where relevant, the test for which the sampling has been assessed, The sampling method, The item sampled and, where relevant, types of samples collected, Type of locations or facilities where samples are collected. Date of Issue: March 1, 2013 IAAC AD 010/13 Page 3 of 6

4 6.3 Estimation of Uncertainty, Quality Assurance and Validation for Sampling: There are many sources of possible uncertainty in a measurement, in practice; including carrying out non representative sampling (the sample measured may not represent the defined measurand). Therefore laboratories carrying out sampling should have mechanisms guaranteeing that the taking of the sample or sampling, transportation, custody of the sample and the time between the collection and the beginning of the analysis, do not invalidate test results. 6.4 Sampling Plan Design: In a sampling process, the definition of the sampling plan establishes the level of confidence of extrapolating the result obtained from the sample(s) and the true value in the item sampled. Therefore, in the establishing of the sampling plan and in order to determine the level of confidence aimed, the following factors should be taken into account: Necessary technical competence of people performing sampling Legal criteria Technical criteria Economic criteria Preferably, criteria established in public available documents should be used, for example: standards, official methods, regulations, documents created by the owner of the scheme whenever existing, methods created by scientific or technical relevant associations, etc. 6.5 Assessment of Sampling by the AB: The following aspects should be considered (see section 5, for criteria) : a. Sampling plan. b. Taking of sample. c. Handling and transportation of samples and, if applicable, the need of a custody chain. d. Identification and traceability of samples. e. Relevant requirements affecting the traceability and uncertainty of testing, during sampling. f. Criteria of acceptance or denial of samples. g. Storage of samples. h. Authorizations and qualifications of personnel responsible for sampling. i. Testing reports and records. j. Compliance of statutory requirements whenever applicable. Date of Issue: March 1, 2013 IAAC AD 010/13 Page 4 of 6

5 6.6 Presentation of Reports: The requirements related to information about sampling in test report are given in ISO/IEC Test reports and calibration certificates Each test report or calibration certificate shall include at least the following information, unless the laboratory has valid reasons for not doing so: h) reference to the sampling plan and procedures used by the laboratory or other bodies where these are relevant to the validity or application of the results; In addition to the requirements listed in and , test reports containing the results of sampling shall include the following, where necessary for the interpretation of test results: a) the date of sampling; b) unambiguous identification of the substance, material or product sampled (including the name of the manufacturer, the model or type of designation and serial numbers as appropriate); c) the location of sampling, including any diagrams, sketches or photographs; d) a reference to the sampling plan and procedures used; e) details of any environmental conditions during sampling that may affect the interpretation of the test results; f) any standard or other specification for the sampling method or procedure, and deviations, additions to or exclusions from the specification concerned. The laboratories receiving samples directly at their premises should indicate in the testing report that the sample tested was delivered by the client. 6.7 Cases where the laboratory performs testing but the laboratory does not carry out sampling because it is done by another section of the organization, but the result is affected by sampling. Generally, in organizations performing activities that are different from testing, sampling activities (sampling and taking samples) are performed by another Unit, Division or Department. It is expected that these activities are carried out according to specific requirements of ISO/IEC17025: Requirement 5.7 from the Standard ISO/IEC 17025: 2005, Demonstrating competence, training and qualification of the personnel responsible for sampling, requirement 5.2 of the Standard ISO/IEC 17025: Date of Issue: March 1, 2013 IAAC AD 010/13 Page 5 of 6

6 Having appropriate equipment, requirement 5.5 from the Standard ISO/IEC 17025: Appropriate handling of the samples, requirement 5.8 from the Standard ISO/IEC 17025: The Management System of the Laboratory. References: ACCREDITATION OF SAMPLING AND REQUIREMENTS Leopoldo Cortez, IPQ Portuguese Institute for Quality, Portugal. IPAC Portuguese Accreditation Institute, Rua Antonio Geao, 2, P Caparica PORTUGAL. phone: ISO/IEC 17025:2005: General requirements for the competence of testing and calibration laboratories ISO/IEC 17000:2004: Conformity assessment - Vocabulary and general principles. APLAC TC 005 INTERPRETATION AND GUIDANCE ON THE ESTIMATION OF UNCERTAINTY OF MEASUREMENT IN TESTING ENAC: NT-43 Rev 1 September 2008 Testing Laboratories: Sampling and Sample Taking Accreditation. POSITION STATEMENT Accreditation of sampling activities. Version 05 April ILAC AIC WG5, Sampling. Date of Issue: March 1, 2013 IAAC AD 010/13 Page 6 of 6