EN 12931:2008

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kemikalije, ki se uporabljajo za pripravo pitne vode - Kemikalije za uporabo v sili - Natrijev dikloroizociaourat, brez vodeProdukte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Produkte für den Notfall - Natriumdichlorisocyanurat, wasserfreiProduits chimiques pour le traitement de l'eau destinée à la consommation humaine - Produits chimiques utilisés en cas d'urgence - Dichloroisocyanurate de sodium, anhydreChemicals used for treatment of water intended for human consumption - Chemicals for emergency use - Sodium dichloroisocyanurate, anhydrous71.100.80Chemicals for purification of water13.060.20Pitna vodaDrinking waterICS:Ta slovenski standard je istoveten z:EN 12931:2008SIST EN 12931:2008en,fr,de01-november-2008SIST EN 12931:2008SLOVENSKI
STANDARDSIST EN 12931:20001DGRPHãþD

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12931July 2008ICS 71.100.80Supersedes EN 12931:2000
English VersionChemicals used for treatment of water intended for humanconsumption - Chemicals for emergency use - Sodiumdichloroisocyanurate, anhydrousProduits chimiques pour le traitement de l'eau destinée à laconsommation humaine - Produits chimiques utilisés encas d'urgence - Dichloroisocyanurate de sodium, anhydreProdukte zur Aufbereitung von Wasser für denmenschlichen Gebrauch - Produkte für den Notfall -Natriumdichlorisocyanurat, wasserfreiThis European Standard was approved by CEN on 28 June 2008.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: rue de Stassart, 36
B-1050 Brussels© 2008 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12931:2008: ESIST EN 12931:2008

General information on sodium dichloroisocyanurate, anhydrous.19 Annex B (normative)
General rules relating to safety.21 Annex C (normative)
Determination of arsenic, antimony and selenium (atomic absorption spectrometry hydride technique).23 Bibliography.30
 Deletion of reference to EU Directive 80/778/EEC of July 15, 1980 in order to take into account the latest Directive in force (see [1]). Other amendments a) section 3.1.2 – inclusion of “Troclosene sodium” as a synonym; b) section 3.1.7 – corrected typo for EINECS reference {“220-767-7” instead of “2-207-67-7”}; c) section 5.2.3.2.2 – corrected typo {“dichromate” instead of “dichrormate”}; d) section 6.1 – inclusion of big bags as permitted means of delivery; e) section 6.2 – updating of risk and safety labelling according to EU directives (Annex I of the Directive 67/548EEC and its latest Adaptations to Technical Progress): 1) addition of N: Dangerous for the environment; 2) addition of R phrase:  R 50/53: Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. 3) addition of S phrases:  S2: Keep out of the reach of children.  S 60: This material and its container must be disposed of as hazardous waste.  S 61: Avoid release to the environment. Refer to special instructions/safety data sheets. f) section 6.4 – addition of “Troclosene sodium” as one possible chemical name. 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, SIST EN 12931:2008

1) Chemical Abstracts Service Registry Number. 2) European Inventory of Existing Commercial Chemical Substances. SIST EN 12931:2008

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, required dosage, contents of other impurities and additives used in the product not stated in this 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.
3) 100 kPa = 1 bar SIST EN 12931:2008

Limit mg/kg of product
Type 1 Type 2 Arsenic (As) max. 10 10 Cadmium (Cd) max. 1 1 Chromium (Cr) max. 6 10 Mercury (Hg) max. 0,02 0,02 Nickel (Ni) max. 3 5 Lead (Pb) max. 4 15 Antimony (Sb) max. 5 5 Selenium (Se) max. 1 1 NOTE Cyanide, which does not exist in a strong oxidizing medium such as sodium dichloroisocyanurate, is not a relevant chemical parameter. Pesticides and polycyclic aromatic hydrocarbons are not by-products of the manufacturing process. For parametric values of sodium dichloroisocyanurate 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 described in ISO 8213. SIST EN 12931:2008

Alternatively a standard volumetric solution can be prepared by the following procedure: Dissolve 24,8 g Na2S2O3 . 5 H2O in a 1 000 ml one-mark volumetric flask in about 0,75 l water. After the temperature has equalized, make up to the mark with water and mix thoroughly.
To standardize: Weigh, to the nearest 0,1 mg, 3,600 g (m) of dry potassium iodate. Dissolve in water in a 1000 ml one-mark volumetric flask, make up to the mark with water and mix (standard reference solution c(1/6 KIO3) = 0,1 mol/l ). Place 200 ml of water in a 500 ml stoppered conical flask, add (2 ± 0,5) g of potassium iodide and stir to dissolve. Then introduce, by means of a pipette, 10,0 ml of sodium thiosulfate solution for standardization, add (15 ± 1) ml of hydrochloric acid solution (diluted 1 + 1 by volume) and (5 ± 1) ml of starch solution (5.2.1.3.4).
Titrate immediately with the potassium iodate standard reference solution until the appearance of a blue coloration persisting for at least 30 s occurs. Record the volume (V1) of iodate used.
The actual concentration, c, of the sodium thiosulfate standard volumetric solution (Na2S2O3.5H2O), expressed in moles per litre is given by the following equation :
VcV11c×=
(1)
where
c1 is the concentration, expressed in moles per litre, of the potassium iodate standard reference solution [c(1/6 KIO3) = 0,1 mol/l ];
V is the volume, in millilitres, of the sodium thiosulfate standard volumetric solution used for the standardization (V= 10 ml);
V1
is the volume, in millilitres, of potassium iodate standard reference solution used in the titration. 5.2.1.2.4 Starch solution, mass fraction 1 %. Make a slurry with (1 ± 0,1) g starch and (5 ± 1) ml water. Add (90 ± 5) ml boiling water to the slurry. Stir to dissolve it and cool the solution. This solution needs refrigeration to avoid the decomposition of the starch which results in a vague end point. Keep the solution cool and use it within one week. SIST EN 12931:2008

5.2.1.3.1 Ordinary laboratory apparatus and glassware. 5.2.1.4 Procedure 5.2.1.4.1 Test portion Weigh, to the nearest 0,1 mg, 0,25 g of the laboratory sample (m0) into a tared stoppered weighing bottle. 5.2.1.4.2 Determination Transfer the test portion to a 200 ml volumetric flask. Add 10 ml of water and 10 ml of glacial acetic acid (5.2.1.2.2), stir for 5 min and then add 100 ml of water and 2 g of potassium iodide (5.2.1.2.1), and mix to dissolve and wait 10 min. Titrate with the sodium thiosulfate standard volumetric solution (5.2.1.2.3) to a light yellow colour. Add 5 ml of the starch solution (5.2.1.2.4) and continue titration to the disappearance of the blue black colour. Record the volume (V1) of the sodium thiosulfate standard volumetric solution used. 5.2.1.5 Expression of results The chlorine (Cl2) content, C1, expressed as a mass fraction in %, is given by the following equation: 100003545,0011×××=mcVC (2) where V1 is the volume, in millilitres, of the sodium thiosulfate solution (5.2.1.2.3) used for the titration; m0 is the mass, in grams, of the test portion (5.2.1.4.1); 0,003545 is the mass, in grams, of chlorine (Cl2) corresponding to 1,00 ml of sodium thiosulfate solution, c(Na2S2O3.5H2O) = 0,1 mol/l; c is the actual concentration, expressed in moles per litre of the sodium thiosulfate standard volumetric solution (5.2.1.2.3). 5.2.1.6 Accuracy The result is accurate to within ± 0,1 %. 5.2.2 Impurities 5.2.2.1 Water 5.2.2.1.1 Principle The water content in sodium dichloroisocyanurate is determined by the mass loss after heating in an oven. The temperature is set at a low level because sodium dichloroisocyanurate can lose chlorine on heating. SIST EN 12931:2008

10021x−=1mmmw (3) where m1 is the mass, in grams, before drying; m2 is the mass, in grams, after drying. 5.2.2.2 Sodium chloride 5.2.2.2.1 General This method applies to products with sodium chloride contents in the range of mass fraction from 0 %
to 0,05 % . 5.2.2.2.2 Principle The sodium dichloroisocyanurate anhydrous is acidified and then digested to remove all traces of available chlorine. Sodium is analysed in solution by atomic absorption spectrometry. 5.2.2.2.3 Reagents
All reagents shall be of a recognized analytical grade and the water used shall conform to grade 3 in accordance with EN ISO 3696. 5.2.2.2.3.1 Sulfuric acid concentrated, (H2SO4) mass fraction 95 % minimum. 5.2.2.2.3.2 Sodium standard stock solution c (Na) = 1 000 µg/ml.
Weigh 2,542 g of sodium chloride that has been previously dried for 1 h at 110 °C. Dissolve with water and make up to the mark with water in a 1 000 ml one-mark volumetric flask. Mix well. 5.2.2.2.4 Apparatus Ordinary laboratory apparatus and glassware, together with the following: SIST EN 12931:2008

product is given by the following equation: 00010542122010032××××=mcC, (4) where m3 is the mass, in grams, of the test portion; c is the concentration, in micrograms per millilitre, of sodium in the test portion as determined from the calibration graph. 5.2.2.2.7 Repeatability limit The absolute difference between two single test results, obtained under repeatability conditions, shall not be greater than the repeatability value, r, as calculated from the following equation:
r = 0,025 z
(5) where
z
is the mean of the two results, expressed in mass fraction in % . SIST EN 12931:2008

: in accordance with ISO 8288:1986, Method A;  Cr
: in accordance with EN 1233;  As, Se and Sb
: in accordance with the method given in Annex C. These methods provide an interim result (y) expressed in milligrams per litre which needs to be converted to give the final concentration according to the equation in 5.2.3.1.4. 5.2.3.1.4 Expression of results From the interim result (y) determined (see 5.2.3.1.3.3), the content, C3, of chemical parameter in the laboratory sample, expressed in milligrams per kilogram of product is given by the following equation: SIST EN 12931:2008

5.2.3.2.1 Principle The element mercury in determined by flameless atomic absorption spectometry in accordance with EN 1483. 5.2.3.2.2 Reagents All reagents shall be of a recognized analytical grade and the water used shall conform to the grade 3 specified in EN ISO 3696. 5.2.3.2.2.1 Potassium permanganate solution, c(KMnO4) = 50 g/l. 5.2.3.2.2.2 Sulfuric acid, concentrated, density p = 1,84 g/ml. 5.2.3.2.2.3 Hydroxylammonium chloride solution, c(NH2OH.HCl) = 100 g/l. 5.2.3.2.2.4 Potassium dichromate solution, c(K2Cr2O7) = 4 g/l in a volume fraction 50 %
nitric acid solution. 5.2.3.2.3 Procedure 5.2.3.2.3.1 Test portion Weigh to the nearest 0,01g, 10 g (m5) of the laboratory sample into a glass beaker. 5.2.3.2.3.2 Test solution Quantitatively transfer the test portion to a 100 ml (V1) volumetric flask. Make up to the mark with water (solution A). Pipette 10 ml of the solution A. Transfer into a 250 ml conical flask, add 60 ml of water, 20 ml of a potassium permanganate solution (5.2.3.2.2.1) and five 1 ml portions of sulfu
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