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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 896:1999 The Europe
2、an Standard EN 896:1998 has the status of a British Standard ICS 71.100.80 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Chemicals used for treatment of water intended for human consumption Sodium hydroxide Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:21:16 GMT+
3、00:00 2006, Uncontrolled Copy, (c) BSI BS EN 896:1999 This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 February 1999 BSI 02-1999 ISBN 0 580 306
4、42 9 Amendments issued since publication Amd. No.DateText affected National foreword This British Standard is the English language version of EN 896:1998. The UK participation in its preparation was entrusted to Technical Committee CII/59, Chemicals for drinking water treatment, which has the respon
5、sibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organiza
6、tions represented on this committee can be obtained on request to its secretary. The United Kingdom did not support this standard at the CEN Enquiry stage and voted against its acceptance at the Formal Vote stage. The principal UK objections were as follows. a) The limits for sodium chloride and sod
7、ium chlorate in Table 1 are expressed as percentages of the sodium hydroxide content whereas the analytical methods described in annex B give the results as the percentage chloride content of the product and the sodium chlorate content in grams per litre in the measured test solution, respectively.
8、Similarly, the limits for toxic substances in Table 2 are expressed as milligrams per kilogram of sodium hydroxide but the calculation described in B.3.6.2 gives the results as milligrams per kilogram of the product and, for mercury, the result of the determination in accordance with ISO 5666-1 will
9、 be in micrograms per litre of test solution. b) In B.2.3.2 the concentrations of sodium carbonate and sodium hydrogen carbonate in the eluant solution are not stated. c) There is confusion regarding the operation of the spectrometer used for the determinations of antimony, arsenic, cadmium, chromiu
10、m, lead, nickel and selenium. The parameters and operating conditions are specified in Table B.3 but the instructions in B.3.5.4.1 require the parametres to be set in accordance with the operating manual of the instruments manufacturer. If there are any conflicts between these two requirements, the
11、BSI technical committee recommends that the parameters in question be set in accordance with the operating manual. Additional information Article 8 of the Council of the European Community Directive 80/778/EEC relating to the quality of water intended for human consumption requires Member States to
12、ensure that substances used in the preparation of drinking water do not cause any contravention of the maximum admissible concentrations prescribed in annex 1 to the Directive. This requirement is given effect in England and Wales by regulation 25 of the Water Supply (Water Quality) Regulation 1989
13、(similar provisions apply in Scotland and Northern Ireland). Regulation 25 makes provision for attaching conditions of use to chemicals which are authorized for use in public water supplies. Details of conditions of use are contained in the Secretary of States List of Approved Products published by
14、the Drinking Water Inspectorate, Floor 2/A1, Ashdown House, 123 Victoria Street, London, SW1E 6DE. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled Interna
15、tional Standards Correspondence Index, or by using the Find facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a Briti
16、sh Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 11 and a back cover. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:21:16 GMT+00:00 2006, Uncontrolled Copy,
17、(c) BSI CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref. No. EN 89
18、6:1998 E EUROPEAN STANDARDEN 896 NORME EUROPE ENNE EUROPA ISCHE NORM August 1998 ICS 71.100.80 Descriptors: potable water, water treatement, chemical compounds, sodium hydroxide, description, physical properties, chemical properties, impurities, toxic substances, tests, labelling, storage, utilizati
19、on English version Chemicals used for treatment of water intended for human consumption Sodium hydroxide Produits chimiques utilise s pour le traitement de leau destine e a la consommation humaine Hydroxyde de sodium Produkte zur Aufbereitung von Wasser fu r den menschlichen Gebrauch Natriumhydroxid
20、 This European Standard was approved by CEN on 22 July 1998. 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 refer
21、ences concerning such national standards may be obtained on application to the Central Secretariat 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 in
22、to its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal,
23、Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:21:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 EN 896:1998 BSI 02-1999 Foreword This European Standard has been prepared by Technical Committee CEN/TC 164, Water supply, the Secretariat
24、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 1999, and conflicting national standards shall be withdrawn at the latest by February 1999. According to the CEN
25、/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden
26、, Switzerland and the United Kingdom. Contents Foreword2 Introduction3 1Scope3 2Normative references3 3Description3 3.1Identification3 3.2Commercial forms3 3.3Physical properties3 3.4Chemical properties4 4Purity criteria4 4.1General4 4.2Composition of commercial product4 4.3Impurities and main by-pr
27、oducts4 4.4Toxic substances5 5Test methods5 5.1Sampling5 5.2Analyses5 6Labelling Transportation Storage5 6.1Means of delivery5 6.2Risk and safety labelling according to the EU Directives6 6.3Transportation regulations and labelling6 6.4Marking6 6.5Storage6 Annex A (informative) General information o
28、n sodium hydroxide7 Annex B (normative) Analytical methods7 Annex C (normative) General rules relating to safety11 Annex D (informative) Bibliography11 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:21:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 3 EN 896:1998 BSI 02-1999 1) Chemica
29、l Abstracts Service Registry Number. 2) European Inventory of Existing Commercial Chemical Substances 3) 100 kPa = 1 bar. Introduction In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by this Standard: 1) this Standard prov
30、ides no information as to whether the product may be used without restriction in any of the Member States of the EU or EFTA; 2) 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 pr
31、oduct remain in force. 1 Scope This European Standard is applicable to sodium hydroxide used for treatment of water intended for human consumption. It describes the characteristics of sodium hydroxide and specifies the requirements and the corresponding test methods for sodium hydroxide. It gives in
32、formation on its use in water treatment. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated refer
33、ences, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN ISO 3696, Water for analytical laboratory use Specific
34、ation and test methods. (ISO 3696:1987) ISO 979, Sodium hydroxide for industrial use Method of assay. ISO 3165, Sampling of chemical products for industrial use Safety in sampling. ISO 3196, Sodium hydroxide for industrial use Determination of carbonates content Titrimetric method. ISO 5666-1:1983,
35、Water quality Determination of total mercury by flameless atomic absorption spectrometry Part 1: Method after digestion with permanganate peroxodisulfate. ISO 6206, Chemical products for industrial use Sampling Vocabulary. ISO 8213, Chemical products for industrial use Sampling techniques Solid chem
36、ical products in the form of particles varying from powders to coarse lumps. 3 Description 3.1 Identification 3.1.1 Chemical name Sodium hydroxide. 3.1.2 Synonym or common name Caustic soda. 3.1.3 Relative molecular mass 40. 3.1.4 Empirical formula NaOH. 3.1.5 Chemical formula NaOH. 3.1.6 CAS Regist
37、ry Number1) 1310-73-2. 3.1.7 EINECS reference2) 215-185-5. 3.2 Commercial forms The product is available as flakes, pearls, solid, or as an aqueous solution of different concentrations. 3.3 Physical properties 3.3.1 Appearance Solid: White, deliquescent. Solution: Clear, slightly turbid colourless s
38、olution, slightly viscous. 3.3.2 Density Solid: 2,1 g/cm3. Bulk density of pearls: about 1,2 kg/dm3. Solution of concentration of 50 % (m/m): 1,52 g/ml at 20 8C. 3.3.3 Solubility (in water) Highly soluble at all temperatures above 20 8C (partial crystallization occurs above concentration 55 % (m/m)
39、(see Figure 1). 3.3.4 Vapour pressure Solution of concentration of 50 % (m/m): 120 Pa at 20 8C; 450 Pa at 40 8C; 5 000 Pa at 80 8C. 3.3.5 Boiling point at 100 kPa3) About 145 8C for a solution of concentration of 50 % (m/m). 3.3.6 Crystallization point +12 8C for a solution of concentration of 50 %
40、(m/m) (see Figure 1). Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:21:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 EN 896:1998 BSI 02-1999 NaOH concentration in % (m/m) Figure 1 3.3.7 Specific heat 3 220 J/kgK at 20 8C for a solution of concentration of 50 % (m/m). 3.3.8 Viscosi
41、ty (dynamic) For a solution of concentration of 50 % (m/m): 100 Pas at 20 8C; 25 Pas at 40 8C; 5 Pas at 80 8C. 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 Solutions of sodium hydroxide are strong
42、ly alkaline. Dilution of sodium hydroxide is very exothermic. 4 Purity criteria 4.1 General Limits have been given for impurities and toxic substances where these are likely to be present in significant quantities from the current production process and raw materials. If a change in the production p
43、rocess or raw materials leads to significant quantities of other impurities or by-products being present, this shall be notified to the user. 4.2 Composition of commercial product The product shall contain not less than 96 % (m/m) of NaOH for the solid form. Typical concentration for solutions of so
44、dium hydroxide is either 50 % (m/m) or 30 % (m/m), and shall be in any case within the manufacturers stated tolerance. 4.3 Impurities and main by-products The product shall conform to the requirements specified in Table 1. The concentration limits refer to pure NaOH 100 % (m/m). Table 1 Impurities I
45、mpurity Limit % (m/m) of NaOH Sodium chloride (NaCl)1)max. 2,4 Sodium carbonate (Na2CO3)2)max. 0,4 Sodium chlorate (NaClO3)3)max. 0,7 1) Too high concentrations can cause problems with some ion exchange resins. 2) Sodium carbonate is formed in contact with atmospheric carbon dioxide. 3)The presence
46、of any oxidizing agent in sodium hydroxide is to be avoided. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:21:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 5 EN 896:1998 BSI 02-1999 4.4 Toxic substances NOTEFor the purpose of this standard, toxic substances are those defined in the
47、EU Directive 80/778/EEC of 15 July, 1980 (see D.1). The content of toxic substances shall conform to with the requirements specified in Table 2. The concentration limits are specified in milligrams per kilogram of NaOH. Table 2 Toxic substances ElementLimit mg/kg of NaOH Type 1Type 2 Arsenic (As)max
48、.210 Cadmium (Cd)max.15 Chromium (Cr)max.110 Mercury (Hg)max.0,11 Nickel (Ni)max.210 Lead (Pb)max.520 Antimony (Sb)max.55 Selenium (Se)max.55 NOTECyanides, pesticides and polycyclic aromatic hydrocarbons are not relevant toxic substances as listed in EU Directive 80/778/EEC because they are not like
49、ly to be found in the raw materials. 5 Test methods 5.1 Sampling Take a sample in accordance with ISO 8213, taking account of ISO 3165 and also ISO 6206. The nature of the caustic alkalis requires special care to be taken at all points of sampling and preparation for analysis. Sampling techniques shall be such as to limit or prevent atmospheric exposure since sodium hydroxides, both as aqueous solutions or as anhydrous products, rapidly absorb moisture and carbon dioxide (and other acid gases) from th