EN 896:2012
(Main)Chemicals used for treatment of water intended for human consumption - Sodium hydroxide
Chemicals used for treatment of water intended for human consumption - Sodium hydroxide
This European Standard is applicable to sodium hydroxide used for treatment of water intended for human consumption. It describes the characteristics and specifies the requirements and the corresponding test methods for sodium hydroxide. It gives information on its use in water treatment. It also determines the rules relating to safe handling and use (see Annex C).
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Natriumhydroxid
Diese Europäische Norm gilt für Natriumhydroxid zur Aufbereitung von Wasser für den menschlichen Gebrauch. Sie beschreibt die Eigenschaften von Natriumcarbonat und legt die Anforderungen sowie die entsprechenden Prüfverfahren für Natriumhydroxid fest. Sie gibt Informationen für die Anwendung von Natriumchlorid in der Wasseraufbereitung. Sie legt darüber hinaus Regeln für die sichere Handhabung und Verwendung fest (siehe Anhang C).
Produits chimiques utilisés pour le traitement de l’eau destinée à la consommation humaine - Hydroxyde de sodium
La présente Norme européenne s’applique à l’hydroxyde de sodium utilisé pour le traitement de l’eau destinée à la consommation humaine. Elle décrit les caractéristiques de l’hydroxyde de sodium et spécifie les exigences et les méthodes d’essai correspondantes. Elle donne des informations sur son emploi dans le traitement de l’eau. Elle détermine également les règles relatives à la manipulation et à l’utilisation en toute sécurité (voir l’Annexe C).
Kemikalije, ki se uporabljajo za pripravo pitne vode - Natrijev hidroksid
Ta evropski standard obravnava natrijev hidroksid, ki se uporablja za pripravo pitne vode. Opisuje značilnosti natrijevega hidroksida ter določa zahteve in ustrezne preskusne metode zanj. Standard podaja informacije za uporabo natrijevega hidroksida pri pripravi vode. Določa tudi pravila za varno ravnanje in uporabo (glej dodatek C).
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2013
1DGRPHãþD
SIST EN 896:2005
Kemikalije, ki se uporabljajo za pripravo pitne vode - Natrijev hidroksid
Chemicals used for treatment of water intended for human consumption - Sodium
hydroxide
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch -
Natriumhydroxid
Produits chimiques utilisés pour le traitement de l’eau destinée à la consommation
humaine - Hydroxyde de sodium
Ta slovenski standard je istoveten z: EN 896:2012
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 .HPLNDOLMH]DþLãþHQMHYRGH Chemicals for purification of
water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 896
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2012
ICS 71.100.80 Supersedes EN 896:2005
English Version
Chemicals used for treatment of water intended for human
consumption - Sodium hydroxide
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Hydroxyde de menschlichen Gebrauch - Natriumhydroxid
sodium
This European Standard was approved by CEN on 16 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 national
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 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, Hungary, 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
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 896:2012: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Description .5
4 Purity criteria .8
5 Test methods . 10
6 Labelling – Transportation – Storage . 12
Annex A (informative) General information on sodium hydroxide . 15
Annex B (normative) Analytical methods . 16
Annex C (normative) General rules relating to safety . 26
Bibliography . 27
Foreword
This document (EN 896:2012) 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 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 rights.
CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 896:2005.
Significant technical differences between this edition and EN 896:2005 are as follows:
a) 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 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, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Introduction
In respect of potential adverse effects on the quality of water intended 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 verifiable 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 of the product covered by this European Standard is subject to regulation or
control by National Authorities.
1 Scope
This European Standard is applicable to sodium hydroxide used for treatment of water intended for human
consumption. It describes the characteristics and specifies the requirements and the corresponding test methods
for sodium hydroxide. It gives information on its use in water treatment. It also determines the rules relating to safe
handling and use (see Annex C).
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 edition of the
referenced document (including any amendments) applies.
EN ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696)
EN ISO 12846:2012, Water quality — Determination of mercury — Method using atomic absorption spectrometry
(AAS) with and without enrichment (ISO 12846:2012)
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 6206, Chemical products for industrial use — Sampling — Vocabulary
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 hydroxide.
3.1.2 Synonym or common name
Caustic soda.
3.1.3 Relative molecular mass
40,0.
3.1.4 Empirical formula
NaOH.
3.1.5 Chemical formula
NaOH.
1)
3.1.6 CAS Registry Number
1310-73-2.
2)
3.1.7 EINECS reference
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: the product is white, deliquescent.
Liquid: the product is a clear solution, slightly turbid colourless solution, slightly viscous.
3.3.2 Density
Solid : the density of this product is 2,1 g/cm .
3.
The bulk density of pearls is 1,2 kg/dm
Liquid : the density of solution is 1,52 g/ml for a product concentration of mass fraction of 50 % at 20 °C.
3.3.3 Solubility in water
The product is highly soluble at all temperatures above 20 °C (partial crystallization occurs above concentration of
mass fraction of 55 %, (see Figure 1).
1) Chemical Abstracts Service Registry Number.
2) European Inventory of Existing Commercial Chemical Substances.
Key
1 temperature in °C.
2 NaOH concentration in mass fraction in %
Figure 1 — Solubility of sodium hydroxide
3.3.4 Vapour pressure
Solution of concentration of mass fraction of 50 %
- 120 Pa at 20 °C;
- 450 Pa at 40 °C;
- 5 000 Pa at 80 °C.
3)
3.3.5 Boiling point at 100 kPa
145 °C for a solution of concentration of mass fraction of 50 %.
3.3.6 Crystallization point
+ 12 °C for a solution of concentration of mass fraction of 50 % (see Figure 1).
3.3.7 Specific heat
3 220 J/(kg K) at 20 °C for a solution of concentration of mass fraction of 50 %.
3.3.8 Viscosity (dynamic)
For a solution of concentration of mass fraction of 50 %:
- 100 Pa.s at 20 °C;
- 25 Pa.s at 40 °C;
- 5 Pa.s at 80 °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 solutions of sodium hydroxide are strongly alkaline.
Dilution of sodium hydroxide is very exothermic.
4 Purity criteria
4.1 General
This European Standard specifies the minimum purity requirements for sodium hydroxide 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.
3) 100 kPa = 1 bar.
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 products 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 leads
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 product shall contain not less than a mass fraction of 96 % of NaOH for the solid form. Typical concentration
for solutions of sodium hydroxide is either a mass fraction of 50 % or 30 % , and shall be in any case within the
manufacturer’s 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 mass fraction of 100 %.
Table 1 — Impurities
Impurity Limit
in mass fraction in
% of NaOH
max. 2,4
a)
Sodium chloride (NaCl)
max. 0,4
b)
Sodium carbonate (Na CO )
2 3
max. 0,7
c)
Sodium chlorate (NaClO )
a) Too high concentrations can cause problems with some ion exchange resins.
b) Sodium carbonate is formed in contact with atmospheric carbon dioxide.
c) The presence of any oxidizing agent in sodium hydroxide is to be avoided.
4.4 Chemical parameters
The product shall conform to the requirements specified in Table 2.
Table 2 — Chemical parameters
Limit in
Parameter mg/kg of NaOH
Type 1 Type 2
Arsenic (As) max. 2 10
Cadmium (Cd) max. 1 5
Chromium (Cr) max. 1 10
Mercury (Hg) max. 0,1 1
Nickel (Ni) max. 2 10
Lead (Pb) max. 5 20
Antimony (Sb) max. 5 5
Selenium (Se) max. 5 5
NOTE Cyanides, pesticides and polycyclic aromatic hydrocarbons are
not relevant in sodium hydroxide. For parametric values of sodium
hydroxide on trace metal content in drinking water, see [1].
5 Test methods
5.1 Sampling
Prepare the laboratory sample(s) required by the relevant procedure described in ISO 8213, observe the
recommendations of ISO 3165 and also take into account ISO 6206. The nature of caustic alkalis requires special
care at all points of sampling and preparation for analysis. Sampling techniques shall be such as to limit or prevent
atmospheric exposure since sodium hydroxides, either as aqueous solutions or as anhydrous products, rapidly
absorb moisture and carbon dioxide (and other acid gases) from the atmosphere. Additional precautions are
necessary if trace constituents are to be determined.
NOTE For sampling liquids see [2].
5.2 Analyses
5.2.1 Main product
5.2.1.1 Total alkalinity
The total alkalinity shall be determined by titration with an acid standard volumetric solution in accordance with
ISO 979.
5.2.1.2 Caustic alkalin
...
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