1、May 2015 Translation by DIN-Sprachendienst.English price group 24No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 07
2、.100.20This standard has been included in the body of DVGW Technical Rules.!%Bf“2316756www.din.deDDIN EN 16421Influence of materials on water for human consumption Enhancement of microbial growth (EMG);English version EN 16421:2014,English translation of DIN EN 16421:2015-05Einfluss von Materialien
3、auf Wasser fr den menschlichen Gebrauch Vermehrung von Mikroorganismen;Englische Fassung EN 16421:2014,Englische bersetzung von DIN EN 16421:2015-05Influence des matriaux sur leau destine la consommation humaine Stimulation de la croissance microbienne (SCM);Version anglaise EN 16421:2014,Traduction
4、 anglaise de DIN EN 16421:2015-05www.beuth.deDocument comprises 67 pagesIn case of doubt, the German-language original shall be considered authoritative.04.15DIN EN 16421:2015-05 2 A comma is used as the decimal marker. National foreword This document (EN 16421:2014) has been prepared by Technical C
5、ommittee CEN/TC 164 “Water supply” (Secretariat: AFNOR, France). The responsible German body involved in its preparation was the DIN-Normenausschuss Wasserwesen (DIN Standards Committee Water Practice), Working Committee NA 119-04-14 AA Werkstoffe und Bauteile in Kontakt mit Trinkwasser. EUROPEAN ST
6、ANDARD NORME EUROPENNE EUROPISCHE NORM EN 16421 December 2014 ICS 07.100.20 English Version Influence of materials on water for human consumption - Enhancement of microbial growth (EMG) Influence des matriaux sur leau destine la consommation humaine - Stimulation de la croissance microbienne (SCM) E
7、influss von Materialien auf Wasser fr den menschlichen Gebrauch - Vermehrung von Mikroorganismen This European Standard was approved by CEN on 25 October 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard t
8、he status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, Fre
9、nch, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria
10、, 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, Switzerland, Turkey
11、 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 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref
12、. No. EN 16421:2014 EEN 16421:2014 (E) 2 Contents Page Foreword 6 Introduction .7 1 Scope 9 2 Normative references 9 3 Terms and definitions 10 4 Influence of materials on water for human consumption Enhancement of microbial growth (EMG) Method 1: Measured by Biomass Production Potential (BPP) measu
13、red by ATP 11 4.1 General . 11 4.2 Principle . 12 4.3 Apparatus 12 4.3.1 Requirements 12 4.3.2 Vessels, containers, stoppers and connectors and general laboratory apparatus . 12 4.3.3 Cleaning . 12 4.3.4 Gloves 12 4.3.5 Plates . 12 4.3.6 Test containers . 13 4.3.7 Test tubes 13 4.3.8 Incubator (or h
14、ot room) 13 4.3.9 Sterilisation ovens 13 4.3.10 Membrane filters . 13 4.3.11 Autoclave . 13 4.4 Reagents 13 4.4.1 Test water 13 4.4.2 Dilution water 14 4.4.3 Potassium dihydrogen orthophosphate solution . 14 4.4.4 Potassium-nitrate solution 14 4.4.5 Sodium acetate solution 15 4.4.6 Inoculum 15 4.4.7
15、 Specifications for controls 15 4.5 Test samples and controls 16 4.5.1 Sampling, transport and storage of test samples . 16 4.5.2 Test piece preparation . 16 4.6 Pre-treatment of test pieces 17 4.6.1 General . 17 4.6.2 Flushing . 17 4.6.3 Stagnation . 17 4.6.4 Prewashing 17 4.7 Test procedure 17 4.7
16、.1 Overview 17 4.7.2 ATP contamination . 18 4.7.3 Preparation of the test container 18 4.7.4 Test pieces 18 4.7.5 Incubation 18 4.7.6 Positive and negative controls 18 4.7.7 Changing of test water . 19 4.7.8 Measurement of ATP concentrations . 19 4.8 Calculation of test results 19 4.8.1 Biomass Prod
17、uction (BP) 19 4.9 Reproducibility and repeatability 22 DIN EN 16421:2015-05 EN 16421:2014 (E) 3 4.10 Test report 22 4.10.1 General . 22 4.10.2 Material/Product information 22 4.10.3 Information on the test procedure . 23 4.10.4 Test results 23 5 Influence of materials on water for human consumption
18、 Enhancement of microbial growth (EMG) Method 2: Measured by biofilm volume 23 5.1 General . 23 5.2 Principle 24 5.3 Basic requirements . 24 5.4 Apparatus and reagents . 24 5.4.1 Disinfectant 24 5.4.2 Test water . 24 5.4.3 Specifications for controls . 25 5.4.4 Test container and test module for pip
19、es and hoses 25 5.4.5 Scraper . 25 5.4.6 Centrifuge . 25 5.4.7 Glassware for centrifugation 25 5.4.8 Flowmeter . 25 5.5 Test samples and test pieces . 25 5.5.1 Sampling, transport and storage . 25 5.5.2 Preparation of test pieces. 26 5.6 Test procedure . 27 5.6.1 General . 27 5.6.2 Test procedure in
20、 test container 27 5.6.3 Test procedure in test module for pipes and hoses 27 5.6.4 Preparation of the test container or test module for pipes and hoses 28 5.6.5 Pre-treatment of test pieces . 28 5.6.6 Removal of test pieces 28 5.6.7 Examination of test pieces . 28 5.6.8 Re-exposure after harvesting
21、 . 28 5.6.9 Centrifugation and determination of biofilm 28 5.6.10 Examination of biofilm 29 5.6.11 Test periods . 29 5.7 Calculation of test results. 30 5.8 Evaluation of satisfactory test performance 31 5.9 Test report 32 5.9.1 General . 32 5.9.2 Material/Product information 32 5.9.3 Information on
22、 the test procedure . 33 5.9.4 Test results 33 6 Influence of materials on water for human consumption Enhancement of microbial growth (EMG) Method 3: Measured by mean dissolved oxygen depletion 34 6.1 General . 34 6.2 Principle 34 6.3 Test premises 34 6.3.1 General . 34 6.3.2 Safety 34 6.4 Apparatu
23、s and reagents . 34 6.4.1 General . 34 6.4.2 Inoculum water 34 6.4.3 Test water . 35 6.4.4 Test containers 36 6.4.5 Dissolved oxygen meter . 37 6.4.6 30 C Incubator/chamber 37 6.4.7 Polyethylene bags . 37 6.4.8 Glass plates . 37 DIN EN 16421:2015-05 EN 16421:2014 (E) 4 6.4.9 Brass couplings 37 6.4.1
24、0 Special glass plates 37 6.5 Preparation of test pieces 37 6.5.1 General . 37 6.5.2 Nature of test pieces 37 6.6 Test piece and test container size 37 6.6.1 General . 37 6.6.2 Test sample storage . 38 6.6.3 Special requirements . 38 6.6.4 Specifications for controls 42 6.6.5 Test water control . 42
25、 6.7 Test procedures 42 6.7.1 Preparation of the test container 42 6.7.2 Incubation 43 6.7.3 Changing the test water . 43 6.7.4 Measurement of dissolved oxygen . 43 6.8 Calculation of results . 44 6.8.1 Calculation of the mean dissolved oxygen difference (MDOD) . 44 6.8.2 Validation of results 44 6.
26、8.3 Repeatability and reproducibility 45 6.9 Test report . 45 6.9.1 General . 45 6.9.2 Material/Product information . 45 6.9.3 Information on the test procedure 47 6.9.4 Results . 47 Annex A (normative) Method 1: Measured by Biomass Production Potential (BPP) measured by ATP Assessment of the suitab
27、ility of test water for its use in the BPP test (biological stability and the need for addition of trace elements) 48 Annex B (normative) Method 1: Measured by Biomass Production Potential (BPP) measured by ATP Protocol of ATP analysis 50 B.1 Introduction . 50 B.2 Apparatus and glassware 50 B.3 Reag
28、ents and auxiliary substances 50 B.3.1 General . 50 B.3.2 Sterile water . 50 B.3.3 ATP solutions for standard dilutions and calibration curves 50 B.3.4 Luciferin/luciferase (enzyme) solution . 51 B.3.5 ATP extraction reagent 52 B.4 Sampling 52 B.5 Procedure 52 B.5.1 General . 52 B.5.2 Blank water 52
29、 B.5.3 Control dilutions . 52 B.5.4 Samples . 52 B.6 Expression of results . 52 B.6.1 Water samples . 52 B.6.2 Material samples . 53 B.7 Test record 53 DIN EN 16421:2015-05 EN 16421:2014 (E) 5 B.8 Quality control of calibration curves . 53 Annex C (informative) Method 1: Measured by Biomass Producti
30、on Potential (BPP) measured by ATP - ATP and its measurement 55 Annex D (informative) Method 1: Measured by Biomass Production Potential (BPP) measured by ATP Evaluating procedures for removal of attached biomass 56 D.1 Introduction 56 D.2 Procedures for removal of Attached Biomass . 56 D.2.1 Genera
31、l . 56 D.2.2 Swabbing 56 D.2.3 Low energy sonication (LES) . 56 D.2.4 High energy sonication (HES) 56 D.3 Effectiveness of removal procedure . 57 Annex E (informative) Method 1: Measured by Biomass Production Potential (BPP) measured by ATP 58 Annex F (informative) Method 2: Measured by biofilm volu
32、me 59 Annex G (informative) Method 2: Measured by biofilm volume . 60 Annex H (informative) Method 3: Measured by mean dissolved oxygen depletion . 63 Bibliography 65 DIN EN 16421:2015-05 EN 16421:2014 (E) 6 Foreword This document (EN 16421:2014) has been prepared by Technical Committee CEN/TC 164 “
33、Water supply”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2015, and conflicting national standards shall be withdrawn at the latest by June 201
34、5. Attention is drawn to the possibility that some of the elements of this 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. According to the CEN/CENELEC Internal Regulations, the national standards organizat
35、ions of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malt
36、a, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. DIN EN 16421:2015-05 EN 16421:2014 (E) 7 Introduction Water intended for human consumption comes into contact with construction products during storage, transportation an
37、d distribution, including water systems inside buildings. The materials used in these products are selected on the basis of technical requirements and criteria regarding their influence on the water quality, e.g. release of substances and effects on odour, flavour or colour of the water. However, wa
38、ter quality problems may also arise when such materials enhance the multiplication of micro-organisms. A test method to determine the enhancement of microbial growth is required as organic substances present in non-metallic materials (either as ingredients, contaminants or process by-products) are c
39、apable of being utilized by micro-organisms and can give rise to a noticeable deterioration in the organoleptic, physical or microbiological quality of the water with which they are in contact. Microbial growth may occur in the water itself or at the material/water interface. Materials with the pote
40、ntial of supporting microbial growth do not necessarily lead to a deterioration in water quality in every situation due to the influence of various environmental factors, e.g. microbial quality of the water, temperature, presence of residual disinfectant or other growth limiting factors. The purpose
41、 of this standard is to describe three European test methods that can be applied to determine the ability of non-metallic materials to enhance microbial growth in drinking water. a) Method 1 determines the Biomass Production Potential (BPP) by using changes in ATP concentrations as a surrogate measu
42、re for active biomass. This method, developed by the Dutch, has been further enhanced as part of the CPDW project 2003 and 2006. b) Method 2 uses a volumetric measurement of the biofilm. This, German method, was first published as DVGW W 270 in 1984 and is used for certification purposes with limit
43、values established for many years. c) Method 3 uses dissolved oxygen depletion in water as a surrogate measure of microbial activity (Mean Dissolved Oxygen Difference MDOD). This British method, first issued as BS DD82 in 1982 and published as BS 6920 Section 2.4 (1988 and 2000), is used for materia
44、ls approval with limit values. Each method thus uses different performance characteristics, which allows its use for specific materials or product types but also has limitations. For example, multi-layer pipes cannot currently be tested with the BPP (Method 1) and the MDOD-method (Method 3), and gre
45、ases or lubricants cannot currently be tested with the BPP (Method 1) and Volumetric-method (Method 2). Harmonised product standards will provide the specific methodology to be followed; this will take into account material of construction and type of components. All three methods use natural mixtur
46、es of aquatic organisms to assess the enhancement of growth by the sample of material. The natural flora comprises many strains that are adapted to living in a relatively hostile environment like drinking water and the results of tests using natural floras have been shown to correlate well with grow
47、th on materials in practice. The numbers, types and growth requirements of harmless micro-organisms present in drinking water vary considerably and no single cultural technique exists to enumerate all the aquatic micro-organisms that may be present in a sample of water. Therefore, overall numbers of
48、 micro-organisms are generally assessed by using simple indirect measurements of their activity. The technique for assessing enhanced microbial growth is different in each of the test methods described in this European Standard. In the BPP method described in Method 1 surface and planktonic microbia
49、l growth is determined using adenosine triphosphate (ATP) as a surrogate method for active biomass determination. In the Volumetric method (DVGW) described in Method 2, the sum of both active and non-active biofilm on the surface of the test material (living and dead micro-organisms as well as extracellular polymeric substances) is determined volumetrically. In the MDOD method described in Method 3 the measurement of dissolved oxygen uptake is used as a surrogate measure of the growth of both biofilm and planktonic aquatic micro-organisms (mos
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