SIST EN 937:2016

SLOVENSKI STANDARD
kSIST FprEN 937:2015
01-november-2015
Kemikalije, ki se uporabljajo za pripravo pitne vode - Klor
Chemicals used for treatment of water intended for human consumption - Chlorine
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Chlor
Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation
humaine - Chlore
Ta slovenski standard je istoveten z: FprEN 937
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 .HPLNDOLMH]DþLãþHQMHYRGH Chemicals for purification of
water
kSIST FprEN 937:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST FprEN 937:2015

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kSIST FprEN 937:2015


FINAL DRAFT
EUROPEAN STANDARD
FprEN 937
NORME EUROPÉENNE

EUROPÄISCHE NORM

September 2015
ICS 71.100.80 Will supersede EN 937:2009
English Version

Chemicals used for treatment of water intended for human
consumption - Chlorine
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Chlore menschlichen Gebrauch - Chlor
This draft European Standard is submitted to CEN members for unique acceptance procedure. 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, 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.

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: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprEN 937:2015 E
worldwide for CEN national Members.

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kSIST FprEN 937:2015
FprEN 937:2015 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Description . 6
3.1 Identification . 6
3.2 Commercial form . 7
3.3 Physical properties . 7
3.4 Chemical properties . 8
4 Purity criteria . 8
4.1 General . 8
4.2 Composition of commercial product . 8
4.3 Impurities and main by-products . 8
4.4 Chemical parameters . 9
5 Test methods . 9
5.1 General . 9
5.2 Sampling . 9
5.3 Analysis . 9
6 Labelling - Transportation - Storage . 9
6.1 Means of delivery . 9
6.2 Labelling in accordance with EU legisation . 10
6.3 Transportation regulations and labelling . 11
6.4 Marking . 12
6.5 Storage . 12
Annex A (informative) General information on chlorine . 13
A.1 Origin . 13
A.2 Use . 13
Annex B (informative) General rules relating to safety . 14
B.1 Rules for safe handling and use . 14
NOTE Further safety and technical information can be obtained from Euro Chlor (see [5, 6,
7, 8]). . 14
B.2 Emergency procedures . 14
Annex C (informative) Determination of nitrogen trichloride (molecular absorption
spectrometry) . 15
C.1 General . 15
C.2 Principle . 15
C.3 Reaction . 15
C.4 Reagents . 15
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C.5 Apparatus . 16
C.6 Sampling and samples . 17
C.7 Procedure . 17
C.8 Calculation and expression of the results . 20
Bibliography . 22

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FprEN 937:2015 (E)
European foreword
This document (FprEN 937:2015) 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 Unique Acceptance Procedure.
This document will supersede EN 937:2009.
Differences between this edition and EN 937:2009 are editorial in order to harmonize the text with
other standards in this series:
a) deletion of reference to Directive 67/548/EEC of 27th June 1967 in order to take into account the
latest Regulation in force (see [2]);
b) amendment of subclause 6.2 according to [2];
c) deletion of reference to Directive 98/8/EC of 16 February 1998 in order to take into account the
latest Regulation in force (see [3]).
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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.
This product is a biocide and needs to comply with the relevant legislation in force. In the European
Union, at the time of publication, this legislation is Regulation (EU) No 528/2012 [3].
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1 Scope
This European Standard is applicable to chlorine used for treatment of water intended for human
consumption. It describes the characteristics of chlorine and specifies the requirements and the
corresponding test methods for chlorine. It gives information on its use in water treatment.
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)
ISO 1552, Liquid chlorine for industrial use — Method of sampling (for determining only the volumetric
chlorine content)
ISO 2120, Liquid chlorine for industrial use — Determination of the content of chlorine by volume in the
vaporized product
ISO 2121, Liquid chlorine for industrial use — Determination of water content — Gravimetric method
ISO 6206, Chemical products for industrial use — Sampling — Vocabulary
3 Description
3.1 Identification
3.1.1 Chemical name
Chlorine.
3.1.2 Synonym or common name
Liquid chlorine.
3.1.3 Relative molecular mass
70,91.
3.1.4 Empirical formula
Cl .
2
3.1.5 Chemical formula
Cl .
2
1)
3.1.6 CAS Registry Number
7782-50-5.

1) Chemical Abstracts Service Registry Number.

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2)
3.1.7 EINECS reference
231-959-5.
3.2 Commercial form
Pressurized liquefied gas.
3.3 Physical properties
3.3.1 Appearance
Liquid chlorine is a clear, amber coloured liquid. Chlorine gas is greenish yellow, 2,5 times heavier than
air. It has a suffocating and characteristic odour.
3.3.2 Density
Liquid: 1,409 g/ml at 20 °C.
Gas:
3
— 3,169 kg/m at 101.3 kPa at 0 °C;
3
— 2,945 kg/m at 101.3 kPa at 20 °C.
3.3.3 Solubility (in water)
7,26 g/l at 20 °C and 100 kPa.
3.3.4 Vapour pressure
669 kPa at 20 °C.
3)
3.3.5 Boiling point at 100 kPa
- 34 °C.
3.3.6 Liquefaction point
- 101 °C at 100 kPa.
3.3.7 Specific heat
Liquid: 920 J/(kg.K) at - 34 °C.
Gas: 475 J/(kg.K) at 0 °C.
3.3.8 Viscosity (dynamic)
-8
Gas: 1 333 × 10 Pa.s at 20 °C.
-4
Liquid: 4,78 × 10 Pa.s at - 34 °C.
3.3.9 Critical temperature
144 °C.

2) European Inventory of Existing Commercial Chemical Substances.
3) 100 kPa = 1 bar.

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3.3.10 Critical pressure
7 710,83 kPa.
3.3.11 Physical hardness
Not applicable.
3.4 Chemical properties
Chlorine is a very strong oxidizing agent and can react violently with some gases such as hydrogen.
Almost all metals form chlorides in the presence of chlorine. Organic compounds including mineral oils
and greases react very quickly with chlorine.
The standard redox potential of gaseous chlorine in neutral aqueous solution at 25 °C and 101.3 mbar
is:
- - 0
Cl + 2e = 2 Cl E =+1,36 V (1)
2 (gas) (aq)
4 Purity criteria
4.1 General
This European Standard specifies the minimum purity requirements for chlorine 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.
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 the product standard.
Limits have been given for impurities and chemicals 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 at least a volume fraction of 99,5 % chlorine.
4.3 Impurities and main by-products
The product shall conform to the requirements specified in Table 1.
Table 1 — Impurities
Impurities Limit in mg/kg of product
Water (H 0) 20
2
a
Nitrogen trichloride (NCl3) 20
a
Valid for containers with a net mass of max. 1 000 kg liquid
chlorine. For tanks with a higher capacity the limit shall be lowered to
10 mg/kg due to safety concerns (see [4] for further details).
NOTE 1 Other by-products consist of inert gases (nitrogen, oxygen, carbon dioxide, hydrogen) in variable
proportions which are not relevant for the purposes described in this European Standard.
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NOTE 2 Carbon tetrachloride, which is used in some chlorine manufacturing plants as an auxiliary solvent in
chlorine processing, and other chlorinated hydrocarbons originating from rubberised or plastic piping might be
present in traces in chlorine, but are not relevant due to the low dosage of chlorine to water intended for human
consumption. Chlorine can also contain traces of bromine, depending on the purity of the salt used in the
electrolytic process and the subsequent chlorine processing.
4.4 Chemical parameters
Heavy metals, which might be present in traces in liquid chlorine, are no relevant chemical parameters
for gaseous chlorine that is applied in water treatment. Cyanide, pesticides and polycyclic aromatic
hydrocarbons are not by-products of the manufacturing process.
NOTE For the purpose of this standard, "chemical parameters" are those defined in the EU Directive
98/83/EC of November 3, 1998 ([1]). For their parametric values in drinking water see [1].”
5 Test methods
5.1 General
The composition of chlorine is usually controlled and monitored by the supplier and not intended to be
performed by users. The methods given for sampling and analysis are intended for use in case of
dispute, and shall be carried out by very competent personnel only.
Due to the potential safety risks when performing sampling and analysis, it is strongly recommended to
take advice of the chlorine producers or specialised laboratories.
5.2 Sampling
Take a sample of liquid chlorine, taking account of ISO 6206, in accordance with the following
techniques:
— ISO 1552 for the determination of chlorine content;
— ISO 2121 for the determination of water content.
5.3 Analysis
5.3.1 Determination of chlorine content
The chlorine content shall be determined in accordance with ISO 2120.
5.3.2 Determination of water content
The water content shall be determined in accordance with ISO 2121.
5.3.3 Determination of nitrogen trichloride content
The nitrogen trichloride content shall be determined in accordance with Annex C.
6 Labelling - Transportation - Storage
6.1 Means of delivery
Chlorine shall be delivered in transportable pressure equipment (cylinders, pressure drums, tanks,
portable tanks, etc.). (See [7]).
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.
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4)
6.2 Labelling in accordance with EU legisation
At the time of publication of this European Standard, the following labelling requirements shall apply to
chlorine:
— Signal Word:

Danger

— Hazard Statements:

H270 May cause or intensify fire; oxidiser

H331 Toxic if inhaled

H319 Causes serious eye irritation

 H335 May cause respiratory irritation
Figure 1 — GHS04

H315 Causes skin irritation

H400 Very toxic to aquatic life

Figure 2 — GHS03

4) See [2].

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Figure 3 — GHS06

Figure 4 — GHS06
The Regulation [2] contains a list of substances classified by the EU. Substances not listed in this
Regulation should be classified on the basis of their intrinsic properties according to the criteria in the
Regulation by the person responsible for the marketing of the substance.
Chlorine used for treatment of water intended for human consumption is applied as a biocidal product.
Therefore, additional labelling requirements according to Regulation (EU) No 528/2012 (see [3]) shall
be applied.
6.3 Transportation regulations and labelling
5)
Chlorine is listed as UN Number 1017.
6)
...