1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationPD CEN/TR 852:2010Plastics piping systems for thetransport of water intendedfor human consumption Migration assessment Guidance on the interpretationof laboratory derivedmigratio
2、n valuesPD CEN/TR 852:2010 PUBLISHED DOCUMENTNational forewordThis Published Document is the UK implementation of CEN/TR852:2010.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/88/4, Test Methods - Plastic Piping.A list of organizations represented on this committee c
3、an beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 69527 8ICS 67.250; 83.140.30Compliance with a British Standard cannot confer immunity fromlegal o
4、bligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 31 January 2011.Amendments issued since publicationDate Text affectedPD CEN/TR 852:2010TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 852 December 2010 ICS 67.250; 83.
5、140.30 Supersedes ENV 852:2001English Version Plastics piping systems for the transport of water intended for human consumption - Migration assessment - Guidance on the interpretation of laboratory derived migration values Systmes de canalisations plastiques pour le transport deau destine la consomm
6、ation humaine - valuation de la migration - Guide dinterprtation des valeurs de migration dtermines en laboratoire Kunststoff-Rohrleitungssysteme fr den Transport von Trinkwasser fr den menschlichen Verzehr - Bewertung der Migration - Anleitung fr die Beurteilung von aus Laborversuchen abgeleiteten
7、Migrationswerten This Technical Report was approved by CEN on 15 May 2010. It has been drawn up by the Technical Committee CEN/TC 155. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hun
8、gary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Cent
9、re: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 852:2010: EPD CEN/TR 852:2010CEN/TR 852:2010 (E) 2 Contents Page Foreword 3Introduction .31 Scope 42 Normative references 43 Terms, defi
10、nitions and symbols .43.1 Terms and definitions .43.2 Symbols 64 Principle 65 Field use .65.1 General 65.2 Factors 75.3 Determination of the conversion factor, F, for pipes, fittings and joints .86 Number of migration periods and assessment procedure .86.1 Number of migrations .86.2 Assessment proce
11、dure .97 Calculation of the field concentration, Cf;nand the acceptance migration limit, Mal. 107.1 Calculation of the field concentration, Cf;n. 107.2 Calculation of the acceptance migration limit, Mal108 Assessment report . 10Annex A (informative) Alternative schedules for successive migration per
12、iods 12Annex B (informative) Determination of the operational factor 13B.1 General . 13B.2 Pipes 13B.3 Fittings and joints . 14Annex C (informative) Example of the determination of the conversion factor, F, for pipes, fittings and joints . 16Bibliography . 17PD CEN/TR 852:2010CEN/TR 852:2010 (E) 3 F
13、oreword This document (CEN/TR 852:2010) has been prepared by Technical Committee CEN/TC 155 “Plastics piping systems and ducting systems”, the secretariat of which is held by NEN. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CE
14、N and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes ENV 852:2001. Introduction This document was originally issued by CEN/TC 155/WG 2 as an ENV. Because of the current developments relating to contact with water intended for human co
15、nsumption, CEN/TC 155 has decided not to ask for a revision of this document as a standard, but to propose instead to keep it as a Technical Report. The main objective of this is to make the information available as quickly as possible to interested groups, particularly those involved in designing t
16、he regulatory framework of harmonised standards, such as a European acceptance scheme. EN ISO 8795 provides instructions on how to produce a migration liquid and how to calculate a migration value (M) after analysis of a migrating substance. However, EN ISO 8795 does not give information on: a) the
17、number of successive migration periods to be carried out; b) how to interpret M values calculated from successive migration periods; c) a method for converting the calculated M values into values that reflect field use conditions; d) acceptance criteria for the duplicate M values obtained by testing
18、 in accordance with EN ISO 8795. This information is included in this document (CEN/TR 852:2010). In the case of the conversion of M values (point c), two factors have been considered: a geometrical factor Fg , which is a property of the product; an operational factor Fo, which is calculated from th
19、e residence time of the water in contact with the product. The values of Foquoted in this document are based on certain assumptions and/or risk analysis. These are explained in the document. PD CEN/TR 852:2010CEN/TR 852:2010 (E) 4 1 Scope This Technical Report is applicable to plastics pipes, joints
20、 and fittings to be used for the transport of water intended for human consumption and raw water used for the manufacture of water intended for human consumption. It gives guidance on: a) the number of successive migration periods to be carried out; b) how to interpret M values calculated from succe
21、ssive migration periods; c) a method for converting M values into values that reflect field use conditions; d) acceptance criteria for the duplicate M values obtained by testing in accordance with EN ISO 8795. 2 Normative references The following referenced documents are indispensable for the applic
22、ation of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 8795, Plastics piping systems for the transport of water intended for human consumption Migration assessment
23、Determination of migration values of plastics pipes and fittings and their joints (ISO 8795:2001) 3 Terms, definitions and symbols For the purposes of this document, the following terms, definitions and symbols apply. 3.1 Terms and definitions 3.1.1 Terms and definitions related to acceptance limits
24、 3.1.1.1 concentration acceptance limit (Cal) concentration of a constituent which shall not be exceeded NOTE 1 It is expressed in milligrams per litre (mg/l). NOTE 2 The limit is specified elsewhere, e.g. in national regulations. 3.1.1.2 migration acceptance limit (Mal) migration value for a consti
25、tuent which shall not be exceeded NOTE 1 It is expressed in milligrams per square decimetres per 24 h mg/(dm2 24 h). NOTE 2 The value is either specified elsewhere e.g. in national regulations or calculated from a concentration acceptance limit Cal (see 3.1.1.1) and a conversion factor F (see 3.1.3.
26、1). PD CEN/TR 852:2010CEN/TR 852:2010 (E) 5 3.1.2 Terms and definitions related to categorisation of pipe lines 3.1.2.1 domestic pipe line pipe line between the service pipe line (see 3.1.2.2) and the tap NOTE It is assumed to have a nominal size in the range 12 to 25 inclusive. 3.1.2.2 service pipe
27、 line pipe line between the distribution pipe line (see 3.1.2.3) and the domestic pipe line (see 3.1.2.1) NOTE It is assumed to have a nominal size in the range 32 and 90 inclusive. 3.1.2.3 distribution pipe line pipe line between a trunk main (see 3.1.2.4) and several service pipe lines (see 3.1.2.
28、2) NOTE It is assumed to have a nominal size in the range 100 to 280 inclusive. 3.1.2.4 trunk main pipe line which transports water from the water works to the distribution pipe line (see 3.1.2.3) NOTE It is assumed to have a nominal size of 300 and larger. 3.1.3 Terms and definitions related to con
29、version factors 3.1.3.1 conversion factor (F) factor used to convert an experimentally derived migration value MT24;n(see 3.2) to Cf;n (see 3.1.3.2) NOTE It is expressed in days and decimetres to power minus one (day/dm). 3.1.3.2 field concentration (Cf;n) calculated concentration of a particular co
30、nstituent under assumed conditions of field use for migration period n NOTE It is expressed in milligrams per litre (mg/l). 3.1.3.3 geometrical factor (Fg) relationship between the surface area of a component of a pipe line in contact with the water and the volume of the water contained by that comp
31、onent (see 5.2.2) NOTE It is expressed in decimetres to the power minus one (dm1). 3.1.3.4 operational factor (Fo) time the water is assumed to be in contact with the component in practice (see 5.2.3) NOTE It is expressed in days. PD CEN/TR 852:2010CEN/TR 852:2010 (E) 6 3.1.4 Terms and definitions r
32、elated to products 3.1.4.1 fitting component other than a pipe which is used in a pipe line (e.g. bends, tees, end caps, valves) EN ISO 8795:2001 3.1.4.2 joint connection between the ends of two components, which includes the method of sealing EN 1444:2000 3.1.4.3 nominal size (DN) numerical designa
33、tion of the size of the pipe, fitting or joint, which is whole number approximately equal to the actual dimensions in millimetres (mm) as specified in the relevant System Standard 3.1.5 water water intended for human consumption or raw water used for the manufacture of water intended for human consu
34、mption 3.2 Symbols n : The sequence number of the migration period (see Clause 5); MTn;24: Migration value M at the temperature T in degrees Celsius, for the migration time 24 h and the migration period n. It is expressed in milligrams per square decimetres per 24 h mg/(dm2 24 h); MT24;n: The arithm
35、etic mean value of the results of the duplicate test pieces MTn;24. 4 Principle A maximum of ten migrations is specified. For assessment purposes the first three and the last three migrations are used. A procedure for the interpretation of successive migrations is provided. Procedures are given for
36、the conversion of laboratory derived migration values to values based on assumed conditions of field use. These values can be compared with either a concentration acceptance limit or with a migration acceptance limit. 5 Field use 5.1 General The concentration Cf;nshall be calculated using Equation (
37、1): Tn24;nMFC = f,(1) PD CEN/TR 852:2010CEN/TR 852:2010 (E) 7 where: Cf;nis the calculated concentration of a particular constituent under assumed conditions of field use in milligrams per litre for migration period n; F is the conversion factor in decimetres power minus one and days; MT24;nis the a
38、rithmetic mean MTn;24values in milligrams per square decimetre per 24 h (day), obtained by application of the relevant test methods and the assessment in accordance with 6.2.2. 5.2 Factors 5.2.1 Conversion factor The conversion factor F shall be calculated using Equation (2): oF F F = g (2) where: F
39、 is the conversion factor (see 3.1.3.1); Fgis the geometrical factor (see 3.1.3.3); Fois the operational factor (see 3.1.3.4). 5.2.2 Geometrical factor The geometrical factor Fgis defined by Equation (3): VSF =g (3) where: Fgis the geometrical factor (see 3.1.3.3); S is the inner surface of the pipe
40、, fitting or joint exposed to the water, in square decimetres (dm2); V is the volume of the water in the pipe, fitting or joint, in cubic decimetres (dm3). For practical purposes Fgshall be calculated using Equation (4): DN400g F = (4) where: Fgis the geometrical factor (see 3.1.3.3); DN is the nomi
41、nal size of the pipe, fitting or joint (see 3.1.4.3), in millimetres (mm). PD CEN/TR 852:2010CEN/TR 852:2010 (E) 8 5.2.3 Operational factor The operational factor Fofor pipes shall be as in Table 1. The operational factor for fittings and joints for all categories shall be 0,05. NOTE In Annex B an e
42、xplanation is given for the determination of Fo. Table 1 Operational factor Fofor pipes Category of pipe line Foin days Domestic pipe line (3.1.2.1) Service pipe line (3.1.2.2) Distribution pipe line (3.1.2.3) Trunk main (3.1.2.4) 0,5 0,5 1,5 1,5 5.3 Determination of the conversion factor, F, for pi
43、pes, fittings and joints From the range of products being assessed, the following shall be established: a) for each product i.e. pipe, fitting or joint the minimum and maximum nominal sizes produced; b) using 5.2.2 as appropriate, determine the categories and then the applicable Fo; c) for each cate
44、gory take either: 1) the smallest nominal size produced, or 2) the smallest nominal size defined for that particular category (see 3.1.2) whichever is the larger, and use equation (4) to calculate Fg; d) from the values obtained for Foand Fgfor each category calculate F using Equation (2). NOTE In A
45、nnex C an example of an assessment of F for pipes, fittings and joints is given. 6 Number of migration periods and assessment procedure 6.1 Number of migrations Migration tests shall be performed in accordance with EN ISO 8795. For each of the first three migration periods determine MT24;nin accorda
46、nce with 6.2.2 and assess the results in accordance with 6.2.1. When using procedure A or B in 6.2.1 if the conditions a) and b) are satisfied then no further migration periods are necessary. If, however, they are not satisfied, then either: a) continue without interruption for a further seven migra
47、tion periods or, PD CEN/TR 852:2010CEN/TR 852:2010 (E) 9 b) start a new series with fresh test pieces and perform ten migration periods. NOTE For practical reasons the decision to continue will often be made prior to results from the first three migration periods being available. In case a) the extr
48、acts of the fourth to the seventh migration periods inclusive shall be discarded without analysis. In case b) the extracts of the first to the seventh migration periods inclusive shall be discarded without analysis. For the migration periods 8, 9 and 10 determine MT24;n. In EN ISO 8795 the duration
49、of the migration period is defined as 72 h for cold water applications and 24 h for hot and warm water applications. For migration periods four to seven inclusive, it is permissible to adjust the times as described in Annex A. 6.2 Assessment procedure 6.2.1 Acceptance criteria A pipe, fitting or joint shall be assessed either by Procedure A or Procedure B as follows. Procedure A: a) the results of the values of the field concentration Cfof the first three migrations show a progressiv
