oSIST prEN 15028:2020

SLOVENSKI STANDARD
01-julij-2020
Kemikalije, ki se uporabljajo za pripravo pitne vode - Natrijev klorat
Chemicals used for treatment of water intended for human consumption - Sodium
chlorate
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Natriumchlorat
Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation
humaine - Chlorate de sodium
Ta slovenski standard je istoveten z: prEN 15028
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 Kemikalije za čiščenje vode Chemicals for purification of
water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2020
ICS 71.100.80 Will supersede EN 15028:2012
English Version
Chemicals used for treatment of water intended for human
consumption - Sodium chlorate
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Chlorate de menschlichen Gebrauch - Natriumchlorat
sodium
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 164.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15028:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Description . 5
4.1 Identification . 5
4.2 Commercial form . 6
4.3 Physical properties . 6
4.4 Chemical properties . 8
5 Purity criteria . 8
5.1 General. 8
5.2 Composition of commercial product . 8
5.3 Impurities and main by-products . 9
5.4 Chemical parameters. 9
6 Test methods . 9
6.1 Sampling . 9
6.2 Analysis . 10
7 Labelling - transportation - storage . 15
7.1 Means of delivery . 15
)
7.2 Labelling according to the EU legislation . 15
7.3 Transportation regulations and labelling . 17
7.4 Marking . 17
7.5 Storage . 17
Annex A (informative) General information on sodium chlorate . 18
Annex B (normative) General rules relating to safety . 19
Annex C (normative) Environmental, health and safety precautions within chemical
laboratory . 20
Bibliography . 21

European foreword
This document (prEN 15028:2020) has been prepared by Technical Committee CEN/TC 164 “Water
supply”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 15028:2012.
In comparison with the previous edition, the following technical modifications have been made:
a) modification of 7.3 on transportation regulations and labelling, adding the sentence “The user must
be aware of the incompatibilities between transported products.”;
b) modification of 7.4 on marking. The requirements of marking are also applied to the accompanying
documents.
Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused
by the product covered by this document:
a) this document 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 document 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 document is subject to regulation
or control by national authorities.
1 Scope
This document is applicable to sodium chlorate used for treatment of water intended for human
consumption. It describes the characteristics of sodium chlorate and specifies the requirements and the
corresponding test methods for sodium chlorate. It gives information on its use in water treatment. It
also determines the rules relating to safe handling and use of sodium chlorate (see normative Annex B)
and gives the environmental, health and safety precautions within chemical laboratory (see
normative Annex C).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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)
EN ISO 11885, Water quality - Determination of selected elements by inductively coupled plasma optical
emission spectrometry (ICP-OES) (ISO 11885)
EN ISO 12846, Water quality - Determination of mercury - Method using atomic absorption spectrometry
(AAS) with and without enrichment (ISO 12846)
ISO 3165, Sampling of chemical products for industrial use - Safety in sampling
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 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
4 Description
4.1 Identification
4.1.1 Chemical name
Sodium chlorate
4.1.2 Synonym or common names
None (for the processes related to treatment of drinking water)
NOTE Commercial names of formulations might exist. Purity needs to be checked in case of use for treatment
of water.
4.1.3 Relative molecular mass
106,45
4.1.4 Empirical formula
NaClO
4.1.5 Chemical formula
NaClO
1)
4.1.6 CAS Registry Number
7775-09-9
2)
4.1.7 EINECS reference
231-887-4
4.2 Commercial form
Sodium chlorate is commercially available in crystalline form or as a powder and as an aqueous
solution.
4.3 Physical properties
4.3.1 Appearance and odour
The product is a colourless solid as a powder or the product is a faint blue to colourless solution.
4.3.2 Density
The density of an aqueous solution of sodium chlorate is given in Table 1.
Table 1 — Density of sodium chlorate solution
Concentration of aqueous solution of Density

sodium chlorate solution
(g/ml at 20 °C)
(Mass fraction in %)
30 1,24
40 1,33
50 1,44
4.3.3 Solubility in water
The solubility of sodium chlorate in water is given in Table 2.

1) Chemical Abstracts Service Registry Number.
2) European Inventory of Existing Commercial Chemical Substances.
Table 2 — Solubility of sodium chlorate
Temperature Solubility
(°C) (g/l)
10 650
20 700
40 780
60 880
4.3.4 Vapour pressure
Not applicable (thermal decomposition occurs at ≥ 400 °C)
3)
4.3.5 Boiling point at 100 kPa
The boiling point of aqueous solutions of sodium chlorate is given in Table 3.
Table 3 — Boiling point at 100 kPa of aqueous solutions of sodium chlorate
Concentration of aqueous solution of 400 450 500 550 600 650 700
sodium chlorate (g NaClO /kg of
saturated solution)
Boiling point (°C) 106 107 109 110 111 113 116
4.3.6 Crystallization
The crystallization point of aqueous solutions of sodium chlorate depending on concentration in water
is given in Table 4.
Table 4 — Crystallization point of sodium chlorate aqueous solutions
Concentration of aqueous solution of Crystallization point
sodium chlorate
(°C)
(mass fraction in %)
40 −20
45 0
50 20
55 32
60 55
4.3.7 Melting point
The melting point (of the solid) is 248 °C; and the thermal decomposition is at ≥ 400 °C.
4.3.8 Viscosity (dynamic)
The relative viscosity of aqueous solutions of mass fraction of 40 % of sodium chlorate compared with
water at the same temperature between 25 °C and 35 °C is 2,07.

3) 100 kPa = 1 bar.
4.3.9 Critical temperature in aqueous solution
Not applicable.
4.3.10 Critical pressure
Not applicable.
4.3.11 Physical hardness
Not applicable.
4.4 Chemical properties
The sodium chlorate is a strong oxidizing agent.
NOTE 1 When an acidic sodium chlorate solution is treated with a reducing agent (e.g. hydrogen peroxide
(EN 902) or oxalic acid), chlorine dioxide can be formed.
NOTE 2 The formation of chlorine dioxide can also be obtained by acidification if the acid applied is capable of
acting as a reducing agent in the current environment.
For the purpose of drinking water treatment, one should use acids of quality in accordance with existing
standards for the purpose: hydrochloric acid (EN 939); sulfuric acid (EN 899); phosphoric acid
(EN 974).
For additional information on sodium chlorate, see Annex A.
5 Purity criteria
5.1 General
This document specifies the minimum purity requirements for sodium chlorate 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 be user and when necessary to relevant authorities.
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.
5.2 Composition of commercial product
The sodium chlorate is commercially available as solid forms usually with a minimum dry mass fraction
of 99 % of NaClO .
Commercial solutions if used for water treatment shall be certified to be made-up on the basis of the
product with a dry mass fraction of 99 %. No additional substances like colorants shall be added to the
basic product or to the solutions.
The content of sodium chlorate in commercially available solutions shall be within 3 % of the
manufacturer's declared value.
5.3 Impurities and main by-products
NOTE Sodium chlorate in crystalline form contains normally a maximum mass fraction of 0,1 % of sodium
chloride (as NaCl).
5.4 Chemical parameters
The product shall conform to the requirements specified in Table 5.
Table 5 — Chemical parameters
Parameter Limit in sodium chlorate
(mass fraction 100 %)
(mg/kg)
Arsenic (As) max. 1
Cadmium (Cd) max. 1
Chromium (Cr) max. 5
Mercury (Hg) max. 1
Nickel (Ni) max. 1
Lead (Pb) max. 1
Antimony (Sb) max. 1
Selenium (Se) max. 1
NOTE Cyanide which does not exist in a strong oxidizing medium such
as sodium chlorate is not a relevant chemical parameter. Pesticides and
polycyclic aromatic hydrocarbons are not by-products of the
manufacturing process. For parametric values of sodium chlorate on trace
metal content in drinking water, see [1].
6 Test methods
6.1 Sampling
6.1.1 General
Observe the recommendations of ISO 3165 and take account of ISO 6206.
6.1.2 Solid
Prepare the laboratory sample(s) required by the relevant procedure described in ISO 8213.
6.1.3 Liquid
6.1.3.1 Sampling from drums and bottles
6.1.3.1.1 General
6.1.3.1.1.1 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.
6.1.3.1.1.2 If the design of the container is such (for example, a narrow-necked bottle) 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 6.1.3.1.1.3.
6.1.3.1.1.3 Examine the surface of the liquid. If there are signs of surface contamination, take
samples from the surface as described in 6.1.3.1.2. Otherwise, take samples as described in 6.1.3.1.3.
6.1.3.1.2 Surface sampling
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 that, when the other
selected containers have been sampled
...