SIST EN 973:2009

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kemikalije, ki se uporabljajo za pripravo pitne vode - Natrijev klorid za regeneracijo ionskih izmenjevalnikovProdukte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Natriumchlorid zum Regenerieren von lonenaustauschernProduits chimiques utilisés pour le traitement de l'eau destinée à la consommation humaine - Chlorure de sodium pour la régénération des résines échangeuses d'ionsChemicals used for treatment of water intended for human consumption - Sodium chloride for regeneration of ion exchangers71.100.80Chemicals for purification of water13.060.20Pitna vodaDrinking waterICS:Ta slovenski standard je istoveten z:EN 973:2009SIST EN 973:2009en,fr,de01-december-2009SIST EN 973:2009SLOVENSKI
STANDARDSIST EN 973:2002/A1:2003SIST EN 973:20021DGRPHãþD



SIST EN 973:2009



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 973August 2009ICS 71.100.80Supersedes EN 973:2002
English VersionChemicals used for treatment of water intended for humanconsumption - Sodium chloride for regeneration of ionexchangersProduits chimiques utilisés pour le traitement de l'eaudestinée à la consommation humaine - Chlorure de sodiumpour la régénération des résines échangeuses d'ionsProdukte zur Aufbereitung von Wasser für denmenschlichen Gebrauch - Natriumchlorid zumRegenerieren von lonenaustauschernThis European Standard was approved by CEN on 23 July 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre:
Avenue Marnix 17,
B-1000 Brussels© 2009 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 973:2009: ESIST EN 973:2009



EN 973:2009 (E)
2 Contents page Foreword . 3Introduction . 41Scope . 52Normative references . 53Description . 53.1Identification . 53.2Commercial forms . 63.3Physical properties . 63.4Chemical properties . 84Purity criteria . 84.1General . 84.2Composition of commercial product . 84.3Impurities and main by-products . 84.4Chemical parameters . 95Test methods . 95.1Sampling . 95.2Analyses . 96Labelling – Transportation - Storage . 106.1Means of delivery . 106.2Risk and safety labelling in accordance with the EU directives
............................................................ 106.3Transportation regulations and labelling .................................................................................................. 106.4Marking ......................................................................................................................................................... 106.5Storage .......................................................................................................................................................... 11Annex A (informative)
General information on sodium chloride . 12A.1Origin . 12A.2Use . 12A.3Rules for safe handling and use . 12A.4Emergency procedures . 12Annex B (normative)
Analytical methods . 14B.1Determination of antimony, arsenic, cadmium, chromium, lead, nickel and selenium
(inductively coupled plasma optical emission spectrometry (ICP/OES)) . 14B.2Determination of total mercury (cold vapour atomic absorption spectrometry) . 18B.3Determination of water-soluble hexacyanoferrate (II) (molecular absorption spectrometry) . 23B.4Determination of potassium (Flame atomic absorption spectrometric method) . 27Annex C (informative)
Determination of cadmium, chromium, nickel and lead (flame atomic
absorption spectrometry . 30 C.1Determination of cadmium . 30C.2Determination of chromium . 34C.3Determination of nickel . 37C.4Determination of lead . 40Annex D (informative)
Determination of arsenic, antimony and selenium (atomic absorption spectrometry hydride technique) . 45D.1General principle. 45D.2Interferences . 45D.3Reagents . 45D.4Apparatus . 47D.5Procedure . 48D.6Calculation . 50Bibliography . 51 SIST EN 973:2009



EN 973:2009 (E)
3 Foreword This document (EN 973:2009) 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 a national standard, either by publication of an identical text or by endorsement, at the latest by February 2010, and conflicting national standards shall be withdrawn at the latest by February 2010. 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 973:2002. Differences between this edition and EN 973:2002 are editorial to harmonise the text with other standards in this series. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 973:2009



EN 973:2009 (E)
4 Introduction In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by this standard: a) this 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 criteria, existing national regulations concerning the use and/or the characteristics of this product remain in force. NOTE Conformity with the 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 covered by this European Standard is subject to regulation or control by National Authorities. SIST EN 973:2009



EN 973:2009 (E)
5 1 Scope This European Standard is applicable to sodium chloride intended for use only in water treatment apparatus, for the regeneration of ion exchangers, intended for water for human consumption. It describes the characteristics and specifies the requirements and the corresponding test methods for sodium chloride. It gives information on its use in water treatment. 2 Normative references The following referenced documents are indispensable for the application 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 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987) ISO 2479, Sodium chloride for industrial use – Determination of matter insoluble in water or in acid and preparation of principal solutions for other determinations ISO 2480, Sodium chloride for industrial use – Determination of sulphate content – Barium sulphate gravimetric method ISO 2482, Sodium chloride for industrial use – Determination of calcium and magnesium contents – EDTA complexometric methods ISO 2483, Sodium chloride for industrial use – Determination of the loss of mass at 110 °C ISO 3165, Sampling of chemical products for industrial use - Safety in sampling ISO 6206, Chemical products for industrial use – Sampling – Vocabulary ISO 6227, Chemical products for industrial use – General method for determination of chloride ions – Potentiometric method ISO 8213, Chemical products for industrial use – Sampling techniques – Solid chemical products in the form of particles varying from powders to coarse lumps 3 Description 3.1 Identification 3.1.1 Chemical name Sodium chloride. 3.1.2 Synonym or common name Salt. 3.1.3 Relative molecular mass 58,45. 3.1.4 Empirical formula NaCl. SIST EN 973:2009



EN 973:2009 (E)
6 3.1.5 Chemical formula NaCl. 3.1.6 CAS Registry Number1
7647-14-5. 3.1.7 EINECS Reference2
231-598-3. 3.2 Commercial forms The product is available as rock salt, sea salt or evaporated salt, and it is supplied as free-flowing crystals or their compacted forms. 3.3 Physical properties 3.3.1 Appearance The product is white and crystalline. 3.3.2 Density The density of the solid crystal is 2,16 g/cm3 at 20 °C. The bulk density depends on the particle size distribution. 3.3.3 Solubility (in water) The solubility of the product depends on the temperature as given in Figure 1.
1 Chemical Abstract Service Registry Number. 2 European Inventory of Existing Commercial Chemical Substances. SIST EN 973:2009



EN 973:2009 (E)
7
Key 1 Transition point
NaCl Æ NaCl.2H2O Figure 1 - Solubility curve for sodium chloride in water 3.3.4 Vapour pressure Not applicable. 3.3.5 Boiling point at 100 kPa3
Not applicable. 3.3.6 Melting point 802 °C. 3.3.7 Specific heat Approximately 850 J/(kg⋅K) at 25 °C for the solid. 3.3.8 Viscosity (dynamic) The viscosity of the saturated solution at 20 °C is approximately 1,9 mPa⋅s. 3.3.9 Critical temperature Not applicable. 3.3.10 Critical pressure Not applicable. 3.3.11 Physical hardness The hardness of solid salt is given as 2 to 2,5 on the Mohs' scale of hardness.
3 100 kPa = 1 bar. SIST EN 973:2009



EN 973:2009 (E)
8 3.4 Chemical properties Sodium chloride is stable, non-volatile and aqueous solutions have good electrical conductivity. Sodium chloride is decomposed by a number of acids. It reacts with sulfuric acid, phosphoric acid and strong oxidizing agents. The reactions are often complex and require heat for completion. NOTE Under certain conditions a sodium chloride solution can cause corrosion of metallic surfaces. 4 Purity criteria 4.1 General This European Standard specifies the minimum purity requirements for sodium chloride for regeneration of ion exchangers used for the treatment of water intended for human consumption. 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. NOTE Users of this product should check the national regulations in order to clarify whether it is of appropriate purity for treatment of water intended for human consumption, taking into account raw water quality, contents of other impurities and additives used in the products not stated in the product standard. Limits have been given for 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 lead to significant quantities of impurities, by-products or additives being present, this shall be notified to the user.
4.2 Composition of commercial product The content of sodium chloride in the dry product shall not be less than:  grade A: mass fraction 99,4 % of dry NaCl;  grade B: mass fraction 98,5 % of dry NaCl. NOTE An anticaking agent, sodium or potassium hexacyanoferrate 4, is allowed up to a maximum level in the final product of 20 mg/kg, expressed as the anhydrous hexacyanoferrate ion [Fe(CN)6]-4 and for the determination see B.3. 4.3 Impurities and main by-products The product shall conform to the requirements specified in Table 1 and Table 2. Table 1 – Impurities Impurity Limit Mass fraction % of NaCI content Water-insoluble matter
Grade A Grade B
max. 0,05 0,35
4 E number 535 or 536 (see [2]). SIST EN 973:2009



EN 973:2009 (E)
9 Table 2 – Moisture content Impurity Limit % (m/m) of NaCI content Moisture content
Dry salt Undried salt
max 0,6 5 Potassium, calcium, magnesium and sulfate are natural impurities. Their contents are not relevant. 4.4 Chemical parameters The product shall conform to the requirements specified in Table 3. Table 3 – Chemical parameters Parameter
Limits in mg/kg of commercial product Arsenic (As) max. 13 Cadmium (Cd) max. 1,3 Chromium (Cr) max. 13 Mercury (Hg) max. 0,26 Nickel (Ni) max. 13 Lead (Pb) max. 13 Antimony (Sb) max. 2,6 Selenium (Se) max. 2,6 NOTE Other chemical parameters and indicator parameters as listed in EU Directive 98/83/EC (see [1]) are not relevant in sodium chloride. 5 Test methods 5.1 Sampling A test sample of about 500 g shall be taken for analysis, ensuring that it is representative of the whole batch, and taking account of ISO 3165 and also ISO 6206. Prepare the laboratory sample(s) required in accordance with ISO 8213. NOTE It should be ensured that no trace of the impurities to be determined is introduced in the sample during the sampling operations. 5.2 Analyses 5.2.1 Main product The percentage mass fraction of sodium chloride (NaCI) shall be determined by calculation, on the basis of the results of the determinations of sulfate (according to ISO 2480), halogens (according to ISO 6227), calcium and magnesium (according to ISO 2482), potassium (see B.4) and loss of mass on drying (according to ISO 2483). Convert sulfate to calcium sulfate and unused calcium to calcium chloride, unless sulfate in sample exceeds the amount necessary to combine with calcium, in which case convert calcium to calcium sulfate and unused sulfate to magnesium sulfate and the remaining sulfate to sodium sulfate. Convert unused magnesium to magnesium chloride. Convert potassium to potassium chloride. Convert unused halogens to sodium chloride. Report the sodium chloride contents on a dry matter basis, multiplying the percentage of sodium chloride by 100/(100 - P), where P is the percentage mass fraction of the loss of mass on drying (see 5.2.2.2). SIST EN 973:2009



EN 973:2009 (E)
10 5.2.2 Impurities 5.2.2.1 Water-insoluble matter The content of water-insoluble matter shall be determined in accordance with ISO 2479. 5.2.2.2 Moisture content The loss of mass at 110 °C shall be determined in accordance with ISO 2483. 5.2.3 Chemical parameters 5.2.3.1 Arsenic, cadmium, chromium, nickel, lead, antimony, selenium The contents of chemical parameters, except for mercury, shall be determined by inductively coupled plasma optical emission spectrometry (ICP/OES) (see B.1). NOTE Alternatively, the determination of contents of some chemical parameters can be carried out by atomic absorption spectrometry (AAS) and the analytical methods are given in Annex C and Annex D. 5.2.3.2 Mercury The content of mercury shall be determined by cold vapour atomic absorption spectrometry (see B.2). 6 Labelling – Transportation - Storage 6.1 Means of delivery Sodium chloride shall be delivered in bulk or in bags. In order that the purity of the product is not affected, the means of delivery shall not have been used previously for any different product or it shall have been specially cleaned and prepared before use. 6.2 Risk and safety labelling in accordance with the EU directives 5 Sodium chloride is not subjected to labelling regulations. NOTE Annex I of the Directive 67/548/EEC on Classification, packaging and labelling of dangerous substances and its amendments and adaptations in the European Union contains a list of substances classified by the EU. Substances not in this Annex I should be classified on the basis of their intrinsic properties according to the criteria in the Directive by the person responsible for the marketing of the substance. 6.3 Transportation regulations and labelling Sodium chloride is not listed under a UN Number6 . Sodium chloride is not classified as a dangerous product for road, rail, sea and air transportation. 6.4 Marking Each container shall be marked with at least the following information:  the name "sodium chloride, regeneration salt" or "sodium chloride, salt for water softening”, "compacted dry salt" or "undried salt", trade name and grade;  the net mass;
5 See [3]. 6 United Nations Number. SIST EN 973:2009



EN 973:2009 (E)
11  the name and the address of the supplier and/or manufacturer;  the statement "this product conforms to EN 973". 6.5 Storage 6.5.1 Long term stability Sodium chloride is stable during long term storage, providing it is kept in a dry place. 6.5.2 Storage incompatibilities Sodium chloride shall be stored in hygienic and safe conditions so as to avoid any risk of contamination. The product shall not be allowed to come into contact with sulfuric acid, phosphoric acid and strong oxidizing agents. SIST EN 973:2009



EN 973:2009 (E)
12 Annex A
(informative)
General information on sodium chloride A.1 Origin
a) Rock salt: salt produced by mining salt deposits of different geological formations derived from ancient seas. b) Sea salt: salt produced by seawater evaporation via the action of sun and wind. c) Evaporated salt: salt produced by evaporating water from a salt solution in a special evaporator leading to the recrystallization of the salt. A.2 Use A.2.1 Function Regeneration of the resin in ion exchange apparatus is performed with a solution of sodium chloride. A.2.2 Form in which the product is used It is used in the form of a saturated solution that is diluted before being applied to the resin. A.2.3 Consumption of salt for regeneration of resins The consumption is variable and depends on the mineral content of water, the type of resin and the performance of the apparatus. A.2.4 Means of application An appropriate dosage device such as a metering pump controls the sodium chloride consumption. A.2.5 Secondary effects in ion exchange apparatus None. A.2.6 Removal of excess product Not applicable. A.3 Rules for safe handling and use No particular precaution is necessary. A.4 Emergency procedures A.4.1 First aid Not applicable. SIST EN 973:2009



EN 973:2009 (E)
13 A.4.2 Spillage The product should be collected, then the area should be rinsed with plenty of water. A.4.3 Fire Sodium chloride is not combustible. SIST EN 973:2009



EN 973:2009 (E)
14 Annex B
(normative)
Analytical methods B.1 Determination of antimony, arsenic, cadmium, chromium, lead, nickel and selenium (inductively coupled plasma optical emission spectrometry (ICP/OES)) B.1.1 General The range covered for each element is given in the Table B.1. Table B.1 - Concentration range Element Concentration range, in mg/kg of commercial product As 1,0 to 50 Cd 0,15 to 50 Cr 0,1 to 50 Ni 0,25 to 50 Pb 2,5 to 50 Sb 2,0 to 50 Se 1,0 to 50 NOTE Different types of ICP/OES instruments can have different performance levels. The performance depends also on the quality of the reagents. This means that the mentioned values should be considered as indicative values. The limits quoted in Table B.1 are based on the equation ()r10tionquantifica oflimit LOQs×=
where rs is the repeatability standard deviation of test samples having concentrations near the expected LOQ. B.1.2 Principle Dissolution of the sample with nitric acid (0,1 mol/l) and direct nebulization of the acid solution into an inductively coupled argon plasma formed by a high frequency. Measurement of the radiation at specific wavelengths using background correction. NOTE The use of reference element (internal standard) as scandium, yttrium, cobalt, etc. can improve the quality of the results especially using a simultaneous spectrometer. Every mention of this optional reagent (here scandium) is stated in brackets. B.1.3 Reagents All reagents shall be of recognized analytical grade and the water used shall conform to grade 3 in accordance with EN ISO 3696. Store all prepared solutions in polyethylene or polytetrafluorethylene (PTFE) flasks to prevent contamination. B.1.3.1 Nitric acid solution ρ ≈ 1,40 g/ml, mass fraction 65 %. B.1.3.2 Hydrochloric acid solution ρ ≈ 1,19 g/ml, mass fraction 37 %. B.1.3.3 Sodium chloride solution, c(NaCl) = 250 g/l. SIST EN 973:2009



EN 973:2009 (E)
15 Dissolve 250 g of very pure NaCl (high purity grade) with water and transfer to a 1 000 ml volumetric flask. Make up to the mark with water and mix. NOTE The contents of the particular elements in the high purity sodium chloride reagent should be less than one tenth of the lower limits quoted in Table B.1. B.1.3.4 Scandium (reference element) solution, c(Sc) = 50 mg/l. Transfer 50 ml of a scandium stock solution c(Sc) = 1 000 mg/l and 10 ml nitric acid (B.1.3.1) to a 1 000 ml volumetric flask. Make up to the mark with water and mix. B.1.3.5 As, Cd, Cr, Ni, Pb, Sb or Se element, stock solution, c(element) = 1 000 mg/l commercial solution. B.1.3.6 Argon, the pressure shall not less than 700 kPa and the argon used can be compress or liquefied gas. B.1.4 Apparatus Ordinary laboratory apparatus and glassware together with the following: NOTE All vessels (glassware, polyethylene, polypropylene and polytetrafluorethylene (PTFE) flasks) should be washed with hydrochloric acid c(HCl) ≈ 6 mol/l and water successively. B.1.4.1 Inductively coupled plasma optical emission spectrometer ICP/OES fitted with nebulizer for high salt concentration. This instrument can be simultaneous and/or sequential. Typical parameters and operating conditions for the spectrometer are given in Table B.2. Table B.2 - Typical parameters and operating conditions of the spectrometer Parameter Unit Specifications Type
monochromator or/and polychromator Argon humidifier (water)
Yes Argon (B.1.3.6) flows:
 plasma l/min 12 to 15  auxiliary l/min ≈ 1,5  nebulizer l/min ≈ 0,7 Sample flow ml/min ≈ 1,5 RF power W 1 000 to 1 250 Integration time: s
 simultaneous measurement
10  sequential measurement
3 B.1.5 Procedure B.1.5.1 Test portion Weigh, to the nearest 0,1 g, about 10 g of the laboratory sample (m). B.1.5.2 Test solution Transfer the test portion (B.1.5.1) and water to a 100 ml volumetric flask and stir to dissolve. Add 1 ml nitric acid (B.1.3.), [5 ml of scandium solution (B.1.3.4)], make up to the mark with water and mix. SIST EN 973:2009



EN 973:2009 (E)
16 B.1.5.3 Calibration and verification solutions Transfer 40 ml of sodium chloride solution (B.1.3.3), 1 ml of nitric acid (B.1.3.1), [5 ml of scandium solution (B.1.3.4)] and the volumes of mono-element solution (B.1.3.5) given in the Table B.3 to a series of 100 ml one-mark volumetric flasks. Make up to the mark with water and mix. Table B.3 - Calibration solutions for the different elements Calibration solution N° Mono-element solution ml Corresponding concentration (As, Cd, Cr, Ni, Pb, Sb, Se) mg/l 1 a 0 0 2 b 0,250 2,50 3 0,500 5,00 4 c 0,500 5,00 a Blank calibration solution. b Linearity verification solution. c Control solution prepared with different pipettes, flasks and if possible with different stock solutions. B.1.5.4 Determination B.1.5.4.1 Preparation of the apparatus Set all instrument parameters of the optical emission spectrometer (B.1.4.1) in accordance with the operating manual of the instrument's manufacturer. Prepare the analytical procedure including the lines shown in the Table B.4, with background correction, concentrations of calibration solutions 1 and 3 described in B.1.5.3 (and applying the reference technique). Table B.4 - Wavelength per element Element Wavelength nm
line background As 189,082
193,759
Cd 214,438
228,802
Cr 267,716
Ni 221,647 to be determined with Pb 168,220 each instrument Sb 217,581
Se 196,026
Sc 424,683
(internal standard) or
361,384
SIST EN 973:2009



EN 973:2009 (E)
17 B.1.5.4.2 Spectrometric measurements Repeat the measurements for at least five integration periods. Rinse with the blank calibration solution (solution 1) after each solution. Calibrate the instrument with the calibration solutions 1 and 3 (B.1.5.3). Control and check the linearity of the calibration curve by measurement of the following calibration solutions (B.1.5.3) considered as unknown solutions:  solution 3;  solution 1;  solution 1;  solution 2;  solution 4;  solutio
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