1、February 2013 Translation by DIN-Sprachendienst.English price group 12No 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).I
2、CS 71.100.80!$*G“1950736www.din.deDDIN EN 12121Chemicals used for treatment of water intended for humanconsumption Sodium disulfite;English version EN 12121:2012,English translation of DIN EN 12121:2013-02Produkte zur Aufbereitung von Wasser fr den menschlichen Gebrauch Natriumdisulfit;Englische Fas
3、sung EN 12121:2012,Englische bersetzung von DIN EN 12121:2013-02Produits chimiques utiliss pour le traitement de leau destine la consommationhumaine Disulfite de sodium;Version anglaise EN 12121:2012,Traduction anglaise de DIN EN 12121:2013-02SupersedesDIN EN 12121:2005-09www.beuth.deDocument compri
4、ses 21 pagesIn case of doubt, the German-language original shall be considered authoritative.02.13DIN EN 12121:2013-02 2 A comma is used as the decimal marker. National foreword This document (EN 12121:2012) has been prepared by Technical Committee CEN/TC 164 “Water supply” (Secretariat: AFNOR, Fran
5、ce). The responsible German body involved in its preparation was the Normenausschuss Wasserwesen (Water Practice Standards Committee), Working Committee NA 119-04-02 AA Wasseraufbereitung. Users of this standard are advised of the reservations stated in the Introduction of the European Standard and
6、should note that national regulations exist in Germany dealing with water for human consumption, in particular the Trinkwasserverordnung (TrinkwV2001) (German Drinking Water Ordinance). The DIN Standards corresponding to the International Standards referred to in this document are as follows, whereb
7、y EN ISO Standards are only listed below if these have not been published as DIN EN ISO Standards with the same number: EN ISO 3696 DIN ISO 3696 Amendments This standard differs from DIN EN 12121:2005-09 as follows: a) specifications concerning hazard and safety related symbols have been brought in
8、line with the “Globally Harmonized System of Classification, Labelling and Packaging of Chemicals (GHS)” (Global harmonisiertes System zur Einstufung und Kennzeichnung von Chemikalien). Previous editions DIN EN 12121: 1999-01, 2005-09 National Annex NA (informative) Bibliography DIN ISO 3696, Water
9、for analytical laboratory use Specification and test methods Verordnung ber die Qualitt von Wasser fr den menschlichen Gebrauch (Trinkwasserverordnung TrinkwV 2001) (German Drinking Water Ordinance), as of 28 November 2011 (BGBI. I p. 2370), as amended by Article 2, Paragraph 19 of the Act of 22 Dec
10、ember 2011 (BGBI. I p. 3044)*)*)Obtainable from: Bundesministerium der Justiz (German Federal Ministry of Justice) (Internet: http:/www.gesetze-im-internet.de). EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12121 November 2012 ICS 71.100.80 Supersedes EN 12121:2005English Version Chemicals us
11、ed for treatment of water intended for human consumption - Sodium disulfite Produits chimiques utiliss pour le traitement de leau destine la consommation humaine - Disulfite de sodiumProdukte zur Aufbereitung von Wasser fr den menschlichen Gebrauch - Natriumdisulfit This European Standard was approv
12、ed by CEN on 23 September 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationa
13、l 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, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language
14、 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, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hu
15、ngary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Manage
16、ment Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12121:2012: EEN 12121:2012 (E) 2 Contents Page Foreword 3Introduction . 41 Scope 52 Normative references 53 Description . 54 Purity
17、 criteria 75 Test methods 86 Labelling Transportation Storage . 14Annex A (informative) General information on sodium disulfite 17Annex B (normative) General rules relating to safety . 18Bibliography 19DIN EN 12121:2013-02 EN 12121:2012 (E) 3 Foreword This document (EN 12121:2012) has been prepared
18、by Technical Committee CEN/TC 164 “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 May 2013, and conflicting national standards shall be w
19、ithdrawn at the latest by May 2013. 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. This document supersedes EN 12121:2005. The signif
20、icant technical differences between this edition and EN 12121:2005 are as follows: Modification of 6.2 on labelling, deletion of the reference to EU Directive 80/778/EEC of 15 July 1980 in order to take account of the latest Directive in force. According to the CEN/CENELEC Internal Regulations, the
21、national standards organisations 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,
22、 Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. DIN EN 12121:2013-02 EN 12121:2012 (E) 4 Introduction In respect of potential adverse effects on the quality of water intended for human consu
23、mption caused by the product covered by this European Standard: a) this European Standard provides no information as to whether the product may be used without restriction in any of the Member States of the EU or EFTA; b) it should be noted that, while awaiting the adoption of verifiable European cr
24、iteria, existing national regulations concerning the use and/or the characteristics of this product remain in force. NOTE Conformity with this European Standard does not confer or imply acceptance or approval of the product in any of the Member States of the EU or EFTA. The use of the product covere
25、d by this European Standard is subject to regulation or control by National Authorities. DIN EN 12121:2013-02 EN 12121:2012 (E) 5 1 Scope This European Standard is applicable to sodium disulfite used for treatment of water intended for human consumption. It describes the characteristics of sodium di
26、sulfite and specifies the requirements and the corresponding test methods for sodium disulfite. It gives information on its use in water treatment. It also determines the rules relating to safe handling and use (see Annex B). 2 Normative references The following documents, in whole or in part, are n
27、ormatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 3696, Water for analytical laboratory use Specifica
28、tion and test methods (ISO 3696) ISO 3165, Sampling of chemical products for industrial use Safety in sampling ISO 3629, Photography Processing chemicals Specifications for potassium metabisulfite ISO 5993, Sodium hydroxide for industrial use Determination of mercury content Flameless atomic absorpt
29、ion spectrometric method ISO 6206, Chemical products for industrial use Sampling Vocabulary ISO 6353-1, Reagents for chemical analysis Part 1: General test methods ISO 8213, Chemical products for industrial use Sampling techniques Solid chemical products in the form of particles varying from powders
30、 to coarse lumps ISO 9297, Water quality Determination of chloride Silver nitrate titration with chromate indicator (Mohrs method) ISO 22743, Water quality Determination of sulfates Method by continuous flow analysis (CFA) 3 Description 3.1 Identification 3.1.1 Chemical name Sodium disulfite. 3.1.2
31、Synonym or commons names Sodium metabisulfite, sodium pyrosulfite. 3.1.3 Relative molecular mass 190,10. 3.1.4 Empirical formula Na2S2O5. DIN EN 12121:2013-02 EN 12121:2012 (E) 6 3.1.5 Chemical formula Na2S2O5.3.1.6 CAS-Registry Number 1)7681-57-4. 3.1.7 EINECS reference 2)231-673-0. 3.2 Commercial
32、form The product is a crystalline powder.3.3 Physical properties 3.3.1 Appearance and odour The product is a white, free-flowing fine crystalline powder with a slight odour of sulfur dioxide. 3.3.2 Density The density of the product is 2,7 g/cm3at 20 C. The bulk density is approximately 1,3 g/cm3at
33、20 C. 3.3.3 Solubility (in water) The solubility of the product in water is 540 g/l at 20 C. 3.3.4 Vapour pressure Not applicable. 3.3.5 Boiling point at 100 kPa 3)Not applicable. 3.3.6 Crystallisation point The product decomposes above 150 C. 3.3.7 Specific heat Not known. 1) Chemical Abstracts Ser
34、vice Registry Number. 2)European Inventory of Existing Commercial Chemical Substances. 3)100 kPa = 1 bar. DIN EN 12121:2013-02 EN 12121:2012 (E) 7 3.3.8 Viscosity dynamic Not applicable. 3.3.9 Critical temperature Not applicable. 3.3.10 Critical pressure Not applicable. 3.3.11 Physical hardness Not
35、applicable. 3.4 Chemical properties The solution is weakly acid. The pH value of a saturated aqueous solution of sodium disulfite is between 4,5 and 5,0. Sodium disulfite dissolves in water forming sodium hydrogen sulfite. At elevated temperatures ( 150 C) or on contact with acids sulfur dioxide is
36、generated. Sodium disulfite reacts violently with oxidising agents; e.g. with sodium hypochlorite or hydrogen peroxide. 4 Purity criteria 4.1 General This European Standard specifies the minimum purity requirements for sodium disulfite used for the treatment of water intended for human consumption.
37、Limits are given for impurities commonly present in the product. Depending on the raw material and the manufacturing process other impurities may be present and, if so, this shall be notified to the user and when necessary to relevant authorities. Users of this product should check the national regu
38、lations in order to clarify whether it is of appropriate purity for treatment of water intended for human consumption, taking into account raw water quality, required dosage, contents of other impurities and additives used in the products not stated in this product standard. Limits have been given f
39、or impurities and chemical parameters where these are likely to be present in significant quantities from the current production process and raw materials. If the production process or raw materials leads to significant quantities of impurities, by-products or additives being present, this shall be
40、notified to the user. 4.2 Composition of commercial product The content of sodium disulfite shall not be less than a mass fraction of 95 % (Na2S2O5). The concentration of sodium disulfite shall be within 5 % of the manufacturers declared value. DIN EN 12121:2013-02 EN 12121:2012 (E) 8 4.3 Impurities
41、 and main by-products The sum of the content of sodium sulfate and sodium chloride shall not exceed a mass fraction of 5 % of the commercial product. 4.4 Chemical parameters The product shall conform to the requirements specified in Table 1. Table 1 Chemical parameters Parameter Limit mg/kg of comme
42、rcial product Antimony (Sb) max 1 Arsenic (As) max 1 Cadmium (Cd) max 1 Chromium (Cr) max 1 Lead (Pb) max 5 Mercury (Hg) max 1 Nickel (Ni) max 1 Selenium (Se) max 1 NOTE Other chemical parameters and indicator parameters are not relevant in sodium disulfite because the raw materials used in the manu
43、facturing process are free of them. For parametric values of sodium disulfite on trace metal content in drinking water, see 1. 5 Test methods 5.1 Sampling Observe the general recommendations of ISO 3165 and take account of ISO 6206. Prepare the laboratory sample(s) required by the relevant procedure
44、 described in ISO 8213. 5.2 Analyses 5.2.1 General All reagents shall be of a recognised analytical grade and the water used shall conform to the grade 3 specified in EN ISO 3696. 5.2.2 Main product 5.2.2.1 General The sodium disulfite content shall be determined by the method for potassium disulfit
45、e described in ISO 3629. DIN EN 12121:2013-02 EN 12121:2012 (E) 9 5.2.2.2 Principle Sodium disulfite is oxidised with a fixed volume of iodine. The excess of added iodine is titrated with sodium thiosulfate. The determination includes other sulfites in addition to Na2S2O5, therefore the second titra
46、tion, as described in ISO 3629, is omitted for the purpose of this determination. 5.2.2.3 Calculation The formula given in ISO 3629 for potassium disulfite has to be adapted for sodium disulfite. The sodium disulfite content CB1B, expressed as a mass fraction in %, is given by the following formula:
47、 CB1= 4,76 ()()10032ccVm(1) where c2is the actual concentration, in moles per litre, of the sodium thiosulfate solution; c3is the actual concentration, in moles per litre, of the iodine solution; V is the volume, in millilitres, of the sodium thiosulfate solution used for the titration; m is the mas
48、s, in grams, of the test portion used for the titration; 4,76 is a conversion factor for the mass of sodium disulfite equivalent to 1 mole of iodine (i.e. 47,6) X the conversion factor for millilitres to litres (i.e. 0,001) X 100 (for percentage); 100 is the volume, in millilitres of iodine solution
49、 added for total oxidation. 5.2.3 Impurities 5.2.3.1 Sulfate The sulfate content shall be determined in accordance with ISO 22743. 5.2.3.2 Chloride The chloride content shall be determined in accordance with ISO 9297. 5.2.4 Chemical parameters 5.2.4.1 General The content of chemical parameters shall be determined using the procedures specified in Table 2. DIN EN 12121:2013-02 EN 12121:2012 (E) 10 Table 2 Procedures for the determination of chemical parameters Element
