1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 12120:2012Chemicals used for treatmentof water intended for humanconsumption Sodiumhydrogen sulfiteCopyright European Committee for Standardization Provided by IHS under li
2、cense with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 12120:2012. It supersedes BS EN 12120:2005 which is withdrawn.The UK participation in its preparatio
3、n was entrusted to Technical Committee CII/59, Chemicals for drinking water treatment.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for i
4、ts correct application. The British Standards Institution 2013. Published by BSI Standards Limited 2013ISBN 978 0 580 77779 0 ICS 71.100.80 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy
5、 and Strategy Committee on 28 February 2013.Amendments issued since publicationDate T e x t a f f e c t e dCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EUROPEA
6、N STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12120 November 2012 ICS 71.100.80 Supersedes EN 12120:2005English Version Chemicals used for treatment of water intended for human consumption - Sodium hydrogen sulfite Produits chimiques utiliss pour le traitement de leau destine la consommation humaine
7、 - Hydrognosulfite de sodium Produkte zur Aufbereitung von Wasser fr den menschlichen Gebrauch - Natriumhydrogensulfit This European Standard was approved by CEN on 23 September 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving
8、this European Standard the 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 officia
9、l versions (English, French, 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 Au
10、stria, 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, Swe
11、den, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management 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
12、Members. Ref. No. EN 12120:2012: ECopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EN 12120:2012 (E) 2 Contents Page Foreword 3Introduction . 41 Scope 52 Normative
13、 references 53 Description . 54 Purity criteria 75 Test methods 86 Labelling Transportation Storage . 15Annex A (informative) General information on sodium hydrogen sulfite . 17Bibliography 19Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo repr
14、oduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EN 12120:2012 (E) 3 Foreword This document (EN 12120:2012) has been prepared 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
15、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 withdrawn 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
16、 rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 12120:2005. The significant technical differences between this edition and EN 12120:2005 are as follows: Modification of 6.2 on labelling, deletion of the reference to
17、 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 national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, C
18、yprus, 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 and the Uni
19、ted Kingdom. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EN 12120:2012 (E) 4 Introduction In respect of potential adverse effects on the quality of water inte
20、nded for human consumption 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 ve
21、rifiable European criteria, 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 o
22、f the product covered by this European Standard is subject to regulation or control by National Authorities. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EN 12
23、120:2012 (E) 5 1 Scope This European Standard is applicable to sodium hydrogen sulfite used for treatment of water intended for human consumption. It describes the characteristics of sodium hydrogen sulfite and specifies the requirements and the corresponding test methods for sodium hydrogen sulfite
24、. It gives information on its use in water treatment. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest e
25、dition of the referenced document (including any amendments) applies. EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696) ISO 418, Photography Processing chemicals Specifications for anhydrous sodium sulfite ISO 3165, Sampling of chemical products for industria
26、l use Safety in sampling ISO 5993, Sodium hydroxide for industrial use Determination of mercury content Flameless atomic absorption spectrometric method ISO 6206, Chemical products for industrial use Sampling Vocabulary ISO 6353-1, Reagents for chemical analysis Part 1: General test methods ISO 9297
27、, Water quality Determination of chloride Silver nitrate titration with chromate indicator (Mohrs method) ISO 22743, Water quality Determination of sulphates Method by continuous flow analysis (CFA) 3 Description 3.1 Identification 3.1.1 Chemical name Sodium hydrogen sulfite. 3.1.2 Synonym or common
28、s name Sodium bisulfite. 3.1.3 Relative molecular mass 104,6. 3.1.4 Empirical formula NaHSO3. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EN 12120:2012 (E) 6
29、3.1.5 Chemical formula NaHSO3.3.1.6 CAS-Registry Number 1)7631-90-5. 3.1.7 EINECS reference 2)231-548-0. 3.2 Commercial form The product is an aqueous solution with an usual concentration of approximately a mass fraction of 40 % NaHSO3. This corresponds to 520 g NaHSO3per litre. 3.3 Physical propert
30、ies 3.3.1 Appearance and odour The product is a yellowish liquid with a slight odour of sulfur dioxide. 3.3.2 Density The density of the product is 1,3 g/ml to 1,5 g/ml at 20 C. 3.3.3 Solubility (in water) The product is miscible with water. 3.3.4 Vapour pressure The vapour pressure of a solution of
31、 mass fraction of 40 % NaHSO3 is 4 kPa3) at 20 C. 3.3.5 Boiling point at 100 kPa 3)The product decomposes at 100 C. 3.3.6 Crystallisation point A solution of mass fraction of 40 % NaHSO3crystallises at 2 C. 3.3.7 Specific heat The specific heat of the product is 3,15 kJ/(kg K). 1) Chemical Abstracts
32、 Service Registry Number. 2) European Inventory of Existing Commercial Chemical Substances. 3)100 kPa = 1 bar. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EN
33、12120:2012 (E) 7 3.3.8 Viscosity dynamic The viscosity of a solution of mass fraction of 40 % NaHSO3is 4 mPa.s at 25 C. 3.3.9 Critical temperature Not applicable. 3.3.10 Critical pressure Not applicable. 3.3.11 Physical hardness Not applicable. 3.4 Chemical properties The solution is weakly acid. Th
34、e pH value of a commercial solution of mass fraction of 40 % is between 4,5 and 5,0. NaHSO3exists in solution only; if the solution is evaporated the salt which is formed is sodium disulfite. At elevated temperatures ( 100C) sulfur dioxide is generated. Sodium hydrogen sulfite reacts violently with
35、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 hydrogen sulfite used for the treatment of water intended for human consumption. Limits are given for impurities commonly pr
36、esent 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 regulations in order to clarify whether it is o
37、f 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 for impurities and chemical parameters where
38、 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 notified to the user. 4.2 Composition of co
39、mmercial product The commercial product has a concentration of NaHSO3of approximately 520 g/l, which relates to a content of mass fraction of 40 % NaHSO3, corresponding to a mass fraction of 25 % SO2. The concentration of sodium hydrogen sulfite shall be within 5 % of the manufacturers declared valu
40、e. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 12120:2012EN 12120:2012 (E) 8 4.3 Impurities and main by-products The sum of the content of sodium sulfate and sodium chl
41、oride shall not exceed a mass fraction of 5 % of the commercial product, i.e. solution of mass fraction of 40 % NaHSO3. 4.4 Chemical parameters The product shall conform to the requirements specified in Table 1. Table 1 Chemical parameters Parameter Limit mg/kg of commercial product (mass fraction o
42、f 40 % NaHSO3) 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 hydrogen sulfite because the raw materials used in
43、the manufacturing process are free of them. For parametric values of sodium hydrogen sulfite on trace metal content in drinking water, see 1. 5 Test methods 5.1 Sampling 5.1.1 General Observe the general recommendations of ISO 3165 and take account of ISO 6206. 5.1.2 Sampling from drums and bottles
44、5.1.2.1 General 5.1.2.1.1 Mix the contents of each container to be sampled by shaking the container, by rolling it or by rocking it from side to side, taking care not to damage the container or spill any of the liquid. 5.1.2.1.2 If the design of the container is such (for example, a narrow-necked bo
45、ttle) that it is impracticable to use a sampling implement, take a sample by pouring after the contents have been thoroughly mixed. Otherwise, proceed as described in 5.1.2.1.3. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or ne
46、tworking permitted without license from IHS-,-,-BS EN 12120:2012EN 12120:2012 (E) 9 5.1.2.1.3 Examine the surface of the liquid. If there are signs of surface contamination, take samples from the surface as described in 5.1.2.2. Otherwise, take samples as described in 5.1.2.3. 5.1.2.2 Surface sampli
47、ng Take a sample using a suitable ladle. Lower the ladle into the liquid until the rim is just below the surface, so that the surface layer runs into it. Withdraw the ladle just before it fills completely and allow any liquid adhering to the ladle to drain off. If necessary, repeat this operation so
48、 that, when the other selected containers have been sampled in a similar manner, the total volume of sample required for subsequent analysis is obtained. 5.1.2.3 Bottom sampling Take a sample using an open sampling tube, or a bottom-valve sampling tube, suited to the size of container and the viscosity of the liquid. When using an open sampling tube, close it at the top and then lower the bottom end to the bottom of the container. Open the tube and move it rapidly so that the bottom of the tube traverses t
