1、BSI Standards PublicationPD CEN/TR 16797-2:2015Construction products:Assessment of release ofdangerous substances Guidance on the statisticalassessment of declared valuesPart 2: Technical and statistical backgroundPD CEN/TR 16797-2:2015 PUBLISHED DOCUMENTNational forewordThis Published Document is t
2、he UK implementation of CEN/TR16797-2:2015.The UK participation in its preparation was entrusted to TechnicalCommittee B/557, Construction products - Assessment of dangeroussubstances.A list of organizations represented on this committee can beobtained on request to its secretary.This publication do
3、es not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 85718 8ICS 03.120.20; 91.100.01Compliance with a British Standard cannot confer immunity
4、 fromlegal obligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 30 September 2015.Amendments issued since publicationDate Text affectedPD CEN/TR 16797-2:2015TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 16797-2 August
5、2015 ICS 03.120.20; 91.100.01 English Version Construction products: Assessment of release of dangerous substances - Guidance on the statistical assessment of declared values - Part 2: Technical and statistical background Produits de construction - Evaluation de lmission de substances dangereuses -
6、Guide pour lvaluation de la performance et la vrification de sa constance - Partie 2 : Donnes techniques et statistiques This Technical Report was approved by CEN on 16 January 2015. It has been drawn up by the Technical Committee CEN/TC 351. CEN members are the national standards bodies of Austria,
7、 Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, S
8、witzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN nat
9、ional Members. Ref. No. CEN/TR 16797-2:2015 EPD CEN/TR 16797-2:2015CEN/TR 16797-2:2015 (E) 2 Contents Page European foreword . 4 0 Introduction 5 0.1 General . 5 0.2 Background 5 0.3 Assessment of construction products 6 0.4 Reading guide to CEN/TR 16797-2 . 9 0.4.1 General introduction . 9 0.4.2 Ru
10、les of application 9 0.4.3 Statistical background 9 0.4.4 Annexes 9 1 Scope 10 2 Terms, definitions, abbreviations and symbols . 10 2.1 Terms and definitions . 10 2.2 Abbreviations and symbols . 14 3 Context . 16 4 Quality level of performance with respect to the release, emission or content of RDS
11、. 17 5 Methods for statistical assessment of declared values for RDS . 17 5.1 Goal of the assessment 17 5.2 Assessment of the production . 17 5.3 Assessment of clusters 19 5.4 Assessment of no-further-testing 20 5.5 Methods of assessment 23 5.5.1 Introduction 23 5.5.2 Assessment by variables . 23 5.
12、5.3 Assessment by attributes . 24 5.6 Description of the assessment procedure . 24 5.6.1 Type testing . 24 5.6.2 Further-testing . 25 5.6.3 Clusters 26 5.6.4 No-further-testing 29 5.7 Banned substances . 29 6 Assessment by variables . 30 6.1 Single production units 30 6.1.1 Type testing . 30 6.1.2 F
13、urther-testing . 31 6.1.3 Rule of application for products where the test values are significantly below the declared value (Gamma rule) . 33 6.1.4 Rule of application for products where a small number of test results may be expected . 33 6.2 Cluster of production units 34 6.2.1 Type testing . 34 6.
14、2.2 Further-testing . 36 6.2.3 Rule of application for cluster products where the test values are significantly below the declared value (Gamma rule) 37 6.3 No-further-testing 37 6.4 Handling values lower than the detection limit 38 6.5 Identifying outliers 38 PD CEN/TR 16797-2:2015CEN/TR 16797-2:20
15、15 (E) 3 6.6 Choosing a declared value . 39 7 Assessment by attributes . 40 7.1 Single production units 40 7.1.1 Type testing . 40 7.1.2 Further-testing . 41 7.2 Cluster of production units 42 7.2.1 Type testing . 42 7.2.2 Further-testing . 43 7.3 No-further-testing 44 7.4 Handling values lower than
16、 the detection limit 44 7.5 Identifying outliers 44 7.6 Choosing a declared value . 45 8 Statistical principles of the rules of application 45 8.1 Introduction 45 8.2 Assessment of a production part 45 8.3 Test error 50 8.4 Assessment by variables . 51 8.4.1 Type testing and further-testing 51 8.4.2
17、 Test frequency for further-testing . 52 8.4.3 Gamma rule 56 8.4.4 No-further-testing 56 8.5 Assessment by attributes . 57 8.5.1 Type testing and further-testing 57 8.5.2 No-further-testing 59 8.6 Consumers and producers risk . 60 8.6.1 Acceptance and non-acceptance of batches that exceed the declar
18、ed value 60 8.6.2 Estimation of the consumers risk . 63 8.6.3 Practical approach 64 9 Additional sampling requirements 65 9.1 General . 65 9.2 Probabilistic sampling 66 9.3 Judgemental sampling 68 10 Indirect tests 68 10.1 General . 68 10.2 Correlation . 69 10.3 No correlation 70 Annex A Examples of
19、 the rules of application 71 Annex B Distribution of test values 87 Annex C Checklist for Technical Committees . 90 Annex D Model clauses for product standards . 92 Annex E Critical values for assessment by variables 113 Annex F Gamma factor 117 Bibliography 120 PD CEN/TR 16797-2:2015CEN/TR 16797-2:
20、2015 (E) 4 European foreword This document (CEN/TR 16797-2:2015) has been prepared by Technical Committee CEN/TC 351 “Construction products: Assessment of release of dangerous substances”, the secretariat of which is held by NEN. Attention is drawn to the possibility that some of the elements of thi
21、s document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. CEN/TR 16797, Construction products: Assessment of release of dangerous substances Guidance on the statistical assessment of declared values, comprises the
22、following two parts: Part 1: Principles and rules of application; Part 2: Technical and statistical background the present document. PD CEN/TR 16797-2:2015CEN/TR 16797-2:2015 (E) 5 0 Introduction 0.1 General CEN/TR 16797-1 1 provides a brief introduction to declaring performance for the potential re
23、lease, emission and/or content of dangerous substances from or in construction products and gives the principles which underpin the assessment and verification of constancy of performance (AVCP) of the product in respect of such declarations. The main rules of application are introduced, all of whic
24、h satisfy the given principles. CEN/TR 16797-2 provides a more detailed background and technical explanation together with examples and the statistical justification for the rules of application. The definitions and abbreviations listed in Clause 2 also apply to CEN/TR 16797-1. Annex D contains a mo
25、del clause and the rules of application as normative text that may be copied into or cited by product standards. A recommended solution is to copy the model clause into the product standard and specify the rule of application given in CEN/TR 16797-2:2015, Annex D to be used. This Technical Report wa
26、s developed on the basis of experience with the control of release into soil and water. As it is an assessment of data against a declared value regardless of the source of the data, it is the technical view of CEN/TC 351 that these procedures are also valid for the assessment of emission from constr
27、uction products into indoor air and assessment of gamma radiation from construction products. It is suggested that all product technical committees follow the principles set out in this CEN/TR and it is hoped that all regulators will accept that these principles achieve their objectives with respect
28、 to an acceptable AVCP procedure. The rules of application are examples of the ways in which these principles may be applied. There is no obligation on a product technical committee to adopt these rules of application and they are free to determine their own rules of application. The given rules of
29、application may also be used as a benchmark for assessing alternative rules of application. If product technical committees and producers could streamline their approaches in a way that could be accepted by all regulators, it might support a common understanding on the European market and it might e
30、ncourage regulators to harmonize their existing different approaches and requirements on reliability and meaning of performance declarations in legislation and enforcement. 0.2 Background CEN/TC 351 in its Resolution 162 (Milan 2011) has allocated to its TG 7 the task of drafting a technical report
31、with the following content: This technical report provides guidance to Technical Committees on the evaluation of conformity of test results with regard to dangerous substances from or in construction products. Where further-testing is required, methods for assessing whether the product conforms to t
32、he information provided on the potential release of dangerous substances is described and justified. This technical report also describes the conditions and assumptions under which the proposals are given. In undertaking this task, TG 7 reviewed existing systems that are accepted by regulators. In p
33、ractice these were the Dutch Soil Quality Decree system, a statistically based system where the rate of testing is a function of the closeness of the measured values to the regulatory limit value, and the German technical approval system. Technical Approvals normally apply to products not covered by
34、 CEN standards, but in Germany they are also being applied to the characteristic of release of dangerous substances, as this characteristic is not yet covered by CEN procedures. The German Technical Approval defines a rate of routine testing for release (not a constant between different products) an
35、d the product needs to achieve a release not greater than the defined value. The simplicity of this pass/fail criterion has merit, but there is no possibility of reducing the rate of testing (or incentive to the producer to achieve the lowest possible values of potential release) and when used PD CE
36、N/TR 16797-2:2015CEN/TR 16797-2:2015 (E) 6 in a CEN system, the declaration of non-conformity over a period of months would have disproportionate consequences. After reviewing the options, CEN/TC 351 is proposing a single statistically based system that includes the concept of a producer being able
37、to reach a point where no-further-testing is required and a system that is applicable to a wide range of construction products, allowing a uniform assessment of release or emission which is not dependent of the type of construction product. The objective of this CEN/TR is to provide guidance to prod
38、uct technical committees and information to regulators on the statistical assessment of declared values/classes for release, emission or content of dangerous substances. 0.3 Assessment of construction products CEN/TR 15858 2 describes three procedures for classifying the potential release of RDS: wi
39、thout-testing, without-further-testing and further-testing. Without-testing (WT) is a generic procedure where a comprehensive dossier of information containing information and previous test data on release from a product is prepared and submitted to the European Commission. The Commission appoints a
40、n expert group that includes regulators and product experts to review the dossier of information. If approved by the expert group and endorsed by the Commission, the product standard may include generic procedures for declaring classes of release based on composition, without the need for type testi
41、ng and further-testing by the producer. Document DS 129 4, however, describes this procedure as WFT on the basis that a dossier will not be approved without test data. In this technical report, only the term WFT will be used, following the way it is used in DS 129. Where a WFT procedure is not provi
42、ded in the product standard or not selected by the producer, the producer undertakes type testing (TT) to determine the initial rate of further testing. Further-testing usually follows type testing and this is where every batch (called batch testing) or more usually a random batch selected from a de
43、fined period of production is tested (called random testing) and this test result is used with previous test data to show the consistency of production and to determine the frequency of testing. Further-testing by the producer (FT) and the assessment as to whether the declared value is validated usi
44、ng these test data is fully described in this CEN/TR. If the FT (and rarely the TT) shows the product is consistently safe and the distance between the measured values and declared values is large, FT may end provided certain other requirements are met (essentially to ensure the composition of the p
45、roduct or the process is not changed significantly) and with the involvement of an independent third party. The criteria for no-further-testing (NFT) are defined in this technical report. This technical report recommends that any NFT decision is approved and audited by an independent third party. NO
46、TE CEN/TR 15858 2 described this end to FT as without-further-testing, but this term is used in DS 129 4 and in this technical report to mean something else; see text above. All methods of verifying the declared value/class have equal status and validity. Figure 1 shows the outline procedure for the
47、se options. The conditions under which the statistical assessment of declared values/classes described in this CEN/TR applies are: the product is covered by a harmonized European product standard requiring information on the potential release, emission or content of RDS or the contract of supply req
48、uires the provision of information on the potential release of RDS; there is one or more RDS that require FT to confirm the technical class or value declared by the producer; PD CEN/TR 16797-2:2015CEN/TR 16797-2:2015 (E) 7 the FPC system has specifically addressed the control of RDS. This CEN/TR pro
49、vides guidance on the statistical assessment of declared values where type testing followed by further testing is required with respect to RDS for: potential release into soil, groundwater and surface water; potential emission into indoor air; content; potential gamma radiation or emission (exhalation) of radon gas into indoor air to support: declarations of performance made under CE-marking; for showing conformity of RDS restricted at the Community level; for showing conformity of RDS restricted by provisions valid in the plac
