This Technical Report provides guidance on the statistical assessment of declared values with respect to the release, emission and\/or content of dangerous substances. This report provides statisticallybased criteria for type-testing (TT), further-testing (FT) and where a product has been shown to be consistent with measured values for the release, emission or content that are significantly below the declared values, the point where no-further-testing (NFT) is permitted.<\/p>\n
A series of fundamental principles are defined in CEN\/TR 16797-1 and two statistical approaches are defined. The first approach is to use assessment by variables and this approach requires the data to be normally or log-normally distributed. This approach is recommended as the default option. The alternative approach based on assessment by attributes is appropriate for data sets that are not normally or log-normally distributed. The downside to this form of assessment is that more test data are needed for the same level of reliability. CEN\/TR 16797-1 introduces these assessment procedures and CEN\/TR 16797-2 provides more detail and the statistical proof that they satisfy the principles defined in CEN\/TR 16797-1. With both of these approaches the minimum frequency of testing is a function of the distance between the mean value and declared value and the variability of the data set, i.e. the sample standard deviation.<\/p>\n
To reduce the costs of testing, production plants producing a similar product may share data, e.g. be grouping the product into clusters for statistical assessment of declared values. Rules for the use of clusters are given in this document.<\/p>\n
This document also contains rules for identifying outliers within a data set and guidance on using tests other than the reference method for FT.<\/p>\n
A list of tasks for product technical committees is given in this document as is a model clause for including in product standards and rules of applications that may be cited in the product standard or copied into product standards.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 4<\/td>\n | Contents Page <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | European foreword <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 0 Introduction 0.1 General 0.2 Background <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 0.3 Assessment of construction products <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | Figure 1 \u2014 Possibilities of WFT, FT and NFT for construction products <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 0.4 Reading guide to CEN\/TR 16797-2 0.4.1 General introduction 0.4.2 Rules of application 0.4.3 Statistical background 0.4.4 Annexes <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 1 Scope 2 Terms, definitions, abbreviations and symbols 2.1 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 2.2 Abbreviations and symbols <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 3 Context <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4 Quality level of performance with respect to the release, emission or content of RDS 5 Methods for statistical assessment of declared values for RDS 5.1 Goal of the assessment 5.2 Assessment of the production <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 5.3 Assessment of clusters <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 5.4 Assessment of no-further-testing <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | Figure 2 \u2014 WFT-FT-NFT procedures for construction products option 1: third party control <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | Figure 3 \u2014 WFT-FT-NFT procedures for construction products option 2: update dossier <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.5 Methods of assessment 5.5.1 Introduction 5.5.2 Assessment by variables <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.5.3 Assessment by attributes 5.6 Description of the assessment procedure 5.6.1 Type testing <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Figure 4 \u2014 TT procedure, example of assessment by variables based on 5 test values. In the case of NFT more requirements need to be satisfied, see 5.4 5.6.2 Further-testing <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | Figure 5 \u2014 FT procedure based on 5 test values and assessment by variables. In the case of NFT more requirements need to be satisfied, see 5.4. In the case of batch testing a return to random testing is delayed, see 6.2.2 5.6.3 Clusters <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Figure 6 \u2014 FT cluster system based on 10 test values and assessment by variables 5.6.4 No-further-testing 5.7 Banned substances <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 6 Assessment by variables 6.1 Single production units 6.1.1 Type testing Table 1 \u2014 Criteria for ending TT for a single production unit \u2013 assessment by variables <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 6.1.2 Further-testing <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Table 2 \u2014 Test frequency for a single production unit \u2013 assessment by variables <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 6.1.3 Rule of application for products where the test values are significantly below the declared value (Gamma rule) Table 3 \u2014 Test frequency \u2013 gamma factor 6.1.4 Rule of application for products where a small number of test results may be expected <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Table 4 \u2014 Criteria for ending TT \u2013 Gamma rule for a coefficient of variation of 0,65 6.2 Cluster of production units 6.2.1 Type testing Table 5 \u2014 Test frequency for random testing \u2013 Gamma rule for a coefficient of variation of 0,65 <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Table 6 \u2014 Criteria for ending TT for a cluster \u2013 assessment by variables <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 6.2.2 Further-testing Table 7 \u2014 Test frequency for a cluster \u2013 assessment by variables <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 6.2.3 Rule of application for cluster products where the test values are significantly below the declared value (Gamma rule) Table 8 \u2014 Test frequency \u2013 gamma factor 6.3 No-further-testing Table 9 \u2014 Criteria for NFT \u2013 assessment by variables <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 6.4 Handling values lower than the detection limit 6.5 Identifying outliers <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Table 10 \u2014 Critical value GP for testing outliers 6.6 Choosing a declared value <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 7 Assessment by attributes 7.1 Single production units 7.1.1 Type testing Table 11 \u2014 Criteria for ending TT for a single production unit \u2013 Assessment by attributes <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 7.1.2 Further-testing Table 12 \u2014 Test frequency for a single production unit \u2013 Assessment by attributes <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 7.2 Cluster of production units 7.2.1 Type testing Table 13 \u2014 Criteria for ending TT for a cluster \u2013 assessment by attributes <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 7.2.2 Further-testing Table 14 \u2014 Test frequency for a cluster \u2013 assessment by attributes <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 7.3 No-further-testing Table 15 \u2014Criteria for NFT \u2013 assessment by attributes 7.4 Handling values lower than the detection limit 7.5 Identifying outliers <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | 7.6 Choosing a declared value 8 Statistical principles of the rules of application 8.1 Introduction 8.2 Assessment of a production part <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Figure 7 \u2014 Testing consecutive production parts in case of randomly testing every 1 of 2 batches <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | Figure 8 \u2014 Criteria for a conforming part of the production \u2013 OC-curves for 1, 5 and 20 samples based on assessment by variables <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | Figure 9 \u2014 Probability of random testing and batch testing \u2013 assessment by variables 5 batches per production part (n = 5, k = 0,69); P{random testing} + P{batch testing} = 1 <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | Figure 10 \u2014 Change of the histogram (left) and distribution (right) of three different product qualities (from top to bottom a production with 10 %, 30 % and 60 % > LD) due to combining random testing and batch testing \u2013 assessment by variables 5 batc… <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 8.3 Test error <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | 8.4 Assessment by variables 8.4.1 Type testing and further-testing Figure 11 \u2014 Probability of ending TT \u2013 assessment by variables (OC-curves) <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | Figure 12 \u2014 Probability of achieving random testing for FT \u2013 assessment by variables (OC-curves) 8.4.2 Test frequency for further-testing <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | Table 16 \u2014 Critical values for kn for different percentiles and a probability of 90 % Figure 13 \u2014 Probability of achieving frequency criteria \u2013 assessment by variables (OC-curves) <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | Figure 14 \u2014 Probability of achieving a specific testing frequency for n = 5 \u2013 assessment by variables (curves have been derived from the OC-curves of Figure 13) Figure 15 \u2014 Range of possible k5 values for n = 5 \u2014 Assessment by variables <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | Figure 16 \u2014 Percentage of batches which are actually tested \u2013 assessment by variables (n = 5) <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | 8.4.3 Gamma rule 8.4.4 No-further-testing <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | Figure 17 \u2014 Probability of passing NFT \u2013 assessment by variables (OC-curves) 8.5 Assessment by attributes 8.5.1 Type testing and further-testing <\/td>\n<\/tr>\n | ||||||
| 60<\/td>\n | Figure 18 \u2014 Probability of ending TT \u2013 assessment by attributes (OC-curves) Figure 19 \u2014 Probability of achieving random testing for FT \u2013 assessment by attributes (OC-curves) <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | Table 17 \u2014 Values for n and na for different percentiles and a probability of 90 % Figure 20 \u2014 Probability of passing frequency criteria \u2013 assessment by attributes (OC-curves) 8.5.2 No-further-testing <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | Figure 21 \u2014 Probability of achieving NFT \u2013 assessment by attributes 8.6 Consumer\u2019s and producer\u2019s risk 8.6.1 Acceptance and non-acceptance of batches that exceed the declared value 8.6.1.1 General 8.6.1.2 OC-curve <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | Figure 22 \u2014 Probability of accepting and rejecting batches \u2013 assessment by variables 5 batches per production part (n = 5,k = 0,69); P{accepting a batch > LD} + P{accepting a batch \u2264 LD} + P{rejecting a batch > LD} + P{rejecting a batch \u2264 LD} = 1 8.6.1.3 Reduced testing <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | Figure 23 \u2014 Probability of accepting and rejecting batches with respect to the OC-curve combined with reduced testing \u2013 Assessment by variables 5 batches per production part 8.6.1.4 Criterion for returning from batch testing to random testing <\/td>\n<\/tr>\n | ||||||
| 65<\/td>\n | Figure 24 \u2014 Probability of accepting and rejecting batches with respect to the OC-curve, reduced testing and imposed delay \u2013 Assessment by variables 5 batches per production part 8.6.2 Estimation of the consumer\u2019s risk <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | Figure 25 \u2014 Consumer\u2019s risk \u2013 assessment by variables Figure 26 \u2014 Consumer\u2019s risk \u2013 assessment by attributes 8.6.3 Practical approach <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | 9 Additional sampling requirements 9.1 General <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | 9.2 Probabilistic sampling <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | Figure 27 \u2014 Number of samples and increments at 90 % confidence (\u03b1 = 10 %, z1\/2\u03b1 = 1,645) Table 18 \u2014 Number of increments and samples 9.3 Judgemental sampling 10 Indirect tests 10.1 General <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | 10.2 Correlation <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | 10.3 No correlation <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | Annex A Examples of the rules of application A.1 EXAMPLE 1: Assessment by variables for a single production unit <\/td>\n<\/tr>\n | ||||||
| 76<\/td>\n | A.2 EXAMPLE 2: Assessment by attributes for a single production unit <\/td>\n<\/tr>\n | ||||||
| 79<\/td>\n | A.3 EXAMPLE 3: Assessment by variables for a cluster <\/td>\n<\/tr>\n | ||||||
| 82<\/td>\n | A.4 EXAMPLE 4: Assessment by attributes for a cluster <\/td>\n<\/tr>\n | ||||||
| 86<\/td>\n | A.5 EXAMPLE 5: No-further-testing (NFT) \u2013 assessment by variables <\/td>\n<\/tr>\n | ||||||
| 89<\/td>\n | Annex B Distribution of test values B.1 General B.2 Leaching <\/td>\n<\/tr>\n | ||||||
| 90<\/td>\n | Table B.1 \u2014 Distribution of leaching data of 16 different construction products B.3 Release into air B.4 Content <\/td>\n<\/tr>\n | ||||||
| 91<\/td>\n | Table B.2 \u2014 Distribution of content data of 7 different construction products <\/td>\n<\/tr>\n | ||||||
| 92<\/td>\n | Annex C Checklist for Technical Committees <\/td>\n<\/tr>\n | ||||||
| 94<\/td>\n | Annex D Model clauses for product standards D.1 Introduction D.2 Model clause for product standards D.2.1 Statistical assessment of declared values for dangerous substances Table D.1 \u2014 Substances listed in notified regulations for <\/td>\n<\/tr>\n | ||||||
| 95<\/td>\n | D.2.2 No-further-testing D.3 Rules of application for single production units D.3.1 Rule of application using assessment by variables D.3.1.1 General <\/td>\n<\/tr>\n | ||||||
| 96<\/td>\n | D.3.1.2 Type testing <\/td>\n<\/tr>\n | ||||||
| 97<\/td>\n | Table D.2 \u2014 Assessment by variables: Conformity criteria for TT D.3.1.3 Further-testing <\/td>\n<\/tr>\n | ||||||
| 98<\/td>\n | Table D.3 \u2014 Assessment by variables: Minimum test frequency for FT D.3.1.4 No-further-testing <\/td>\n<\/tr>\n | ||||||
| 99<\/td>\n | Table D.4 \u2014 Assessment by variables: Criteria for NFT D.3.2 Rule of application using assessment by variables and the gamma rule D.3.2.1 General <\/td>\n<\/tr>\n | ||||||
| 100<\/td>\n | D.3.2.2 Type testing <\/td>\n<\/tr>\n | ||||||
| 101<\/td>\n | Table D.5 \u2014 Assessment by variables: Conformity criteria for TT for assessment by the gamma rule for data that have a coefficient of variation of 0,65 D.3.2.3 Further-testing <\/td>\n<\/tr>\n | ||||||
| 102<\/td>\n | Table D.6 \u2014 Assessment by variables: Minimum test frequency for FT for testing by the gamma rule for data that have a coefficient of variation of 0,65 D.3.2.4 No-further-testing <\/td>\n<\/tr>\n | ||||||
| 103<\/td>\n | D.3.3 Rule of application using assessment by attributes D.3.3.1 General D.3.3.2 Type testing <\/td>\n<\/tr>\n | ||||||
| 104<\/td>\n | Table D.7 \u2014 Assessment by attributes: Conformity criteria for TT D.3.3.3 Further-testing <\/td>\n<\/tr>\n | ||||||
| 105<\/td>\n | Table D.8 \u2014 Assessment by attributes: Minimum frequency of testing for FT D.3.3.4 No-further-testing <\/td>\n<\/tr>\n | ||||||
| 106<\/td>\n | Table D.9 \u2014 Assessment by attributes: Criteria for NFT D.4 Rules of application for clusters of production units D.4.1 General D.4.2 Management of a cluster of production units <\/td>\n<\/tr>\n | ||||||
| 107<\/td>\n | D.4.3 Rule of application using cluster assessment by variables D.4.3.1 Type testing D.4.3.2 Further-testing D.4.3.3 No-further-testing <\/td>\n<\/tr>\n | ||||||
| 108<\/td>\n | Table D.10 \u2014 Cluster assessment by variables: Conformity criteria for TT <\/td>\n<\/tr>\n | ||||||
| 109<\/td>\n | Table D.11 \u2014 Cluster assessment by variables: Minimum test frequency for FT D.4.4 Rule of application using cluster assessment by attributes D.4.4.1 Type testing <\/td>\n<\/tr>\n | ||||||
| 110<\/td>\n | Table D.12 \u2014 Cluster assessment by attributes: Conformity criteria for TT <\/td>\n<\/tr>\n | ||||||
| 111<\/td>\n | D.4.4.2 Further-testing Table D.13 \u2014 Assessment by attributes: Minimum frequency of testing for FT D.4.4.3 No-further-testing <\/td>\n<\/tr>\n | ||||||
| 112<\/td>\n | D.5 Identifying outliers Table D.14 \u2014 Critical value GP for testing outliers <\/td>\n<\/tr>\n | ||||||
| 113<\/td>\n | D.6 Use of indirect tests D.6.1 General D.6.2 Correlation <\/td>\n<\/tr>\n | ||||||
| 114<\/td>\n | D.6.3 No correlation <\/td>\n<\/tr>\n | ||||||
| 115<\/td>\n | Annex E Critical values for assessment by variables <\/td>\n<\/tr>\n | ||||||
| 119<\/td>\n | Annex F Gamma factor <\/td>\n<\/tr>\n | ||||||
| 122<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Construction products: Assessment of release of dangerous substances. Guidance on the statistical assessment of declared values – Technical and statistical background<\/b><\/p>\n |