EN 12671:2016

Chemicals used for treatment of water intended for human consumption - Chlorine dioxide generated in situ

This European Standard is applicable to chlorine dioxide generated on site for treatment of water intended for human consumption. It describes the characteristics for chlorine dioxide and specifies the composition and the corresponding test methods for chlorine dioxide. It gives information on its use in water treatment. It also determines the rules relating to safe handling and use of chlorine dioxide generated on site (see Annex B).

Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Vor Ort erzeugtes Chlordioxid

Diese Europäische Norm gilt für vor Ort erzeugtes Chlordioxid zur Aufbereitung von Wasser für den menschlichen Gebrauch. Sie beschreibt die Eigenschaften von Chlordioxid und legt die Zusammensetzung sowie die ent¬sprechenden Prüfverfahren für Chlordioxid fest. Sie enthält Angaben für dessen Anwendung in der Wasser¬aufbereitung. Sie legt darüber hinaus Regeln für die sichere Handhabung und Verwendung von vor Ort erzeugtem Chlordioxid fest (siehe Anhang B).

Produits chimiques utilisés pour le traitement de l’eau destinée à la consommation humaine - Dioxyde de chlore généré in situ

La présente Norme européenne est applicable au dioxyde de chlore généré in situ pour le traitement de l’eau destinée à la consommation humaine. Elle décrit les caractéristiques du dioxyde de chlore et précise la composition et les méthodes d’essai correspondantes du dioxyde de chlore. Elle donne des informations sur son emploi pour le traitement de l’eau. Elle fixe également les règles relatives à la sécurité d’emploi et de manipulation du dioxyde de chlore généré in situ (voir l’Annexe B).

Kemikalije, ki se uporabljajo za pripravo pitne vode - Klorov dioksid, proizveden na kraju samem

Ta dokument se uporablja za klorov dioksid, proizveden mestu uporabe, ki se uporablja za pripravo pitne vode. Opisuje lastnosti klorovega dioksida ter določa sestavo in ustrezne preskusne metode v povezavi z njim. Podaja informacije za njegovo uporabo pri pripravi vode. Določa tudi pravila za varno ravnanje s klorovim dioksidom, proizvedenim na mestu uporabe, in njegovo uporabo.

General Information

• Status: Published
• Publication Date: 30-Aug-2016
• Withdrawal Date: 29-Nov-2016
• ICS: 71.100.80 - Chemicals for purification of water
• Technical Committee: CEN/TC 164 - Water supply
• Drafting Committee: CEN/TC 164/WG 9 - Drinking water treatment
• Current Stage: 9092 - Decision on results of review/2YR ENQ - revise - Review Enquiry
• Completion Date: 23-Jun-2022
• Ref Project: SIST EN 12671:2016 - Chemicals used for treatment of water intended for human consumption - Chlorine dioxide generated in situ

Relations

• Replaces: EN 12671:2009 - Chemicals used for treatment of water intended for human consumption - Chlorine dioxide generated in situ
• Effective Date: 01-Jun-2016

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 12671:2016
01-julij-2016
1DGRPHãþD
SIST EN 12671:2009

Kemikalije, ki se uporabljajo za pripravo pitne vode - Klorov dioksid, proizveden na

kraju samem
Chemicals used for treatment of water intended for human consumption - Chlorine
dioxide generated in situ
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Vor Ort
erzeugtes Chlordioxid

Produits chimiques utilisés pour le traitement de l’eau destinée à la consommation

humaine - Dioxyde de chlore généré in situ
Ta slovenski standard je istoveten z: EN 12671:2016
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 .HPLNDOLMH]DþLãþHQMHYRGH Chemicals for purification of
water
SIST EN 12671:2016 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 12671:2016
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SIST EN 12671:2016
EN 12671
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2016
EUROPÄISCHE NORM
ICS 71.100.80 Supersedes EN 12671:2009
English Version
Chemicals used for treatment of water intended for human
consumption - Chlorine dioxide generated in situ

Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den

destinée à la consommation humaine - Dioxyde de menschlichen Gebrauch - Vor Ort erzeugtes

chlore généré in situ Chlordioxid
This European Standard was approved by CEN on 18 March 2016.

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
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12671:2016 E

worldwide for CEN national Members.
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SIST EN 12671:2016
EN 12671:2016 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Description ........................................................................................................................................................ 6

3.1 Identification .................................................................................................................................................... 6

3.1.1 Chemical name ................................................................................................................................................. 6

3.1.2 Synonym or common name ......................................................................................................................... 6

3.1.3 Relative molecular mass ............................................................................................................................... 6

3.1.4 Empirical formula ........................................................................................................................................... 6

3.1.5 Chemical formula ............................................................................................................................................ 6

3.1.6 CAS Registry Number .................................................................................................................................... 6

3.1.7 EINECS reference ............................................................................................................................................ 6

3.2 Presentation form ........................................................................................................................................... 7

3.3 Physical properties ......................................................................................................................................... 7

3.3.1 Appearance ........................................................................................................................................................ 7

3.3.2 Density ................................................................................................................................................................ 7

3.3.3 Solubility in water ........................................................................................................................................... 7

3.3.4 Vapour pressure .............................................................................................................................................. 7

3.3.5 Boiling point at 101,3 kPa ........................................................................................................................... 8

3.3.6 Crystallization point ....................................................................................................................................... 8

3.3.7 Specific heat ...................................................................................................................................................... 8

3.3.8 Viscosity (dynamic) ........................................................................................................................................ 8

3.3.9 Critical temperature ...................................................................................................................................... 8

3.3.10 Critical pressure .............................................................................................................................................. 8

3.3.11 Physical hardness ........................................................................................................................................... 8

3.3.12 Dissolution heat ............................................................................................................................................... 8

3.4 Chemical properties ....................................................................................................................................... 8

4 Purity criteria ................................................................................................................................................... 9

4.1 General ................................................................................................................................................................ 9

4.2 Composition of in situ generated product .............................................................................................. 9

4.3 Impurities and main by-products ............................................................................................................. 9

4.4 Chemical parameters ..................................................................................................................................... 9

5 Test methods ................................................................................................................................................. 10

5.1 Sampling .......................................................................................................................................................... 10

5.2 Determination of chlorine dioxide and chlorite concentrations ................................................ 10

5.2.1 General ............................................................................................................................................................. 10

5.2.2 Principle .......................................................................................................................................................... 10

5.2.3 Reagents .......................................................................................................................................................... 11

5.2.4 Apparatus ........................................................................................................................................................ 12

5.2.5 Procedure........................................................................................................................................................ 12

5.2.6 Expression of results ................................................................................................................................... 13

6 Labelling, distribution and storage ....................................................................................................... 13

6.1 Labelling according to the EU legislation ........................................................................................... 13

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6.2 Means of distribution .................................................................................................................................. 15

6.3 Storage, stability ........................................................................................................................................... 15

Annex A (informative) General information on chlorine dioxide ............................................................ 16

A.1 Origin ................................................................................................................................................................ 16

A.1.1 Raw materials ................................................................................................................................................ 16

A.1.2 Manufacturing process ............................................................................................................................... 16

A.2 Use ...................................................................................................................................................................... 17

A.2.1 Function ........................................................................................................................................................... 17

A.2.2 Form in which it is used.............................................................................................................................. 17

A.2.3 Treatment dose ............................................................................................................................................. 17

A.2.4 Means of application .................................................................................................................................... 17

A.2.5 Secondary effects .......................................................................................................................................... 17

A.2.6 Removal of excess product ........................................................................................................................ 17

A.3 Spectrometric method for specific determination of CIO ............................................................ 17

A.3.1 Principle ........................................................................................................................................................... 17

A.3.2 Reagents ........................................................................................................................................................... 18

A.3.3 Apparatus ........................................................................................................................................................ 18

A.3.4 Procedure ........................................................................................................................................................ 19

A.3.5 Precision .......................................................................................................................................................... 20

A.3.6 Specificity ........................................................................................................................................................ 20

A.4 Determination of chlorite and chlorate ions contents in aqueous chlorine dioxide as

produced by the reactors ........................................................................................................................... 20

A.4.1 General ............................................................................................................................................................. 20

A.4.2 Sample collection and preparation ........................................................................................................ 20

A.4.3 Principle ........................................................................................................................................................... 20

A.4.4 Reagents ........................................................................................................................................................... 20

A.4.5 Apparatus ........................................................................................................................................................ 21

A.4.6 Procedure ........................................................................................................................................................ 21

A.4.7 Expression of results ................................................................................................................................... 22

A.4.8 Detection limit ............................................................................................................................................... 22

Annex B (normative) General rules relating to safety .................................................................................. 23

B.1 Rules for safe handling and use ............................................................................................................... 23

B.2 Emergency procedures ............................................................................................................................... 23

B.2.1 First aid ............................................................................................................................................................ 23

B.2.2 Spillage ............................................................................................................................................................. 23

B.2.3 Fire ..................................................................................................................................................................... 23

Bibliography ................................................................................................................................................................. 24

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SIST EN 12671:2016
EN 12671:2016 (E)
European foreword

This document (EN 12671:2016) 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 November 2016, and conflicting national standards

shall be withdrawn at the latest by November 2016.

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 12671:2009.

Significant technical differences between this edition and EN 12671:2009 are as follows:

a) deletion of reference to EU Directive 67/548/EEC of June 27, 1967 in order to take into account the

latest Regulation in force (see [3]);

b) Subclause 6.2 – updating of risk and safety labelling according to EU Regulation [3] and its latest

Adaptations to Technical Progress).

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,

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.
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SIST EN 12671:2016
EN 12671:2016 (E)
Introduction

In respect of potential adverse effects on the quality of water intended for human consumption, caused

by the product covered by this document:

1) 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;

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 product remain in force.

NOTE 1 Conformity with this 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 document is subject to regulation or

control by National Authorities.

NOTE 2 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 [2]).

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SIST EN 12671:2016
EN 12671:2016 (E)
1 Scope

This European Standard is applicable to chlorine dioxide generated on site for treatment of water

intended for human consumption. It describes the characteristics for chlorine dioxide and specifies the

composition and the corresponding test methods for chlorine dioxide. It gives information on its use in

water treatment. It also determines the rules relating to safe handling and use of chlorine dioxide

generated on site (see Annex B).
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 3165, Sampling of chemical products for industrial use — Safety in sampling
ISO 6206, Chemical products for industrial use — Sampling — Vocabulary
3 Description
3.1 Identification
3.1.1 Chemical name
Chlorine dioxide.
3.1.2 Synonym or common name
None.
3.1.3 Relative molecular mass
67,46.
3.1.4 Empirical formula
ClO .
3.1.5 Chemical formula
_ _
O Cl O (resonance structure).
3.1.6 CAS Registry Number
10049-04-4.
3.1.7 EINECS reference
233-162-8.
1) Chemical Abstracts Service Registry Number.
2) European Inventory of Existing Commercial Chemical Substances.
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3.2 Presentation form

For water treatment, chlorine dioxide is generated in situ as an aqueous solution on or near the site of

use and transferred to the site of use.
3.3 Physical properties
3.3.1 Appearance

The pure product is an orange gas or liquid, which forms a yellow solution in water.

NOTE If the solution becomes red-brown, it is a sign of decomposition.
3.3.2 Density
Gas: 3,09 g/l, (2,4 g/l relative, air = 1) at 273 K and 101,3 kPa .
Liquid: 1,64 g/ml at 20 °C.
3.3.3 Solubility in water

In Table 1 the solubility values (S) for chlorine dioxide are given in grams per cubic meter (g/m ) water

at a pressure of 101,3 kPa for different temperatures:
Table 1 — Solubility values
Temperature of water S
g / mHO
( )
g / m gas
0 70 ± 0,7
5 (60,3)
10 (53,7)
15 45
20 (42,7)
25 (33)
30 (30,1)
35 26,5 ± 0,8
NOTE 1 S is a ratio, not an absolute value of concentration.

NOTE 2 The S values are directly measured values except those in brackets which are extrapolated data.

3.3.4 Vapour pressure

The vapour pressure of pure chlorine dioxide as a function of temperature is given in Table 2.

3) 100 kPa = 1 bar.
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EN 12671:2016 (E)
Table 2 — Vapour pressure of pure chlorine dioxide
Temperature Vapour pressure
[C°] [kPa]
0 82,3
5 90,4
10 98,8
11 100,5
20 116,5 (extrapolated)
25 125,8 (extrapolated)
30 135,3 (extrapolated)
35 145,1 (extrapolated)
40 155,0 (extrapolated)
3.3.5 Boiling point at 101,3 kPa
11 °C (for pure chlorine dioxide).
3.3.6 Crystallization point
- 59 °C (for pure chlorine dioxide).
3.3.7 Specific heat

The specific heat of solutions of chlorine dioxide is very similar to that of pure water.

3.3.8 Viscosity (dynamic)

The dynamic viscosity of solutions of chlorine dioxide is very similar to that of pure water.

3.3.9 Critical temperature
153 °C (for pure chlorine dioxide).
3.3.10 Critical pressure
Not applicable.
3.3.11 Physical hardness
Not applicable.
3.3.12 Dissolution heat
The heat of the dissolution in water is – 26,8 kJ/mol (exothermic).
3.4 Chemical properties

Chlorine dioxide is a molecule containing an unpaired electron and has the characteristics of a

“molecule-free-radical”. Relevant Redox potentials of chlorine dioxide and related molecules are (E

values at 25 °C in volts):
4) 100 kPa = 1 bar.
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SIST EN 12671:2016
EN 12671:2016 (E)
+ - - E = 1,57 V
HCIO + 3H + 4e ⇒ CI + 2H O
2 2
- - E = 1,15 V
CIO (dissolved gas) + 1e ⇒ CIO
2 2
- - + ⇒ ClO + H O E = 1,15 V
2 2 0
CIO + 1e + 2H
- - E = 0,95 V
ClO (dissolved liquid) + 1e ⇒ CIO
2 2
- - + - E = 0,78 V
CIO + 4e + 4 H ⇒ CI + 2H O
2 2
4 Purity criteria
4.1 General

This European Standard specifies the minimum purity requirements for chlorine dioxide generated in

situ 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 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.
4.2 Composition of in situ generated product

Chlorine dioxide (ClO ) is produced as aqueous solution on or near the site of use. For safety reasons

the aqueous ClO solution without intermediate storage in a storage tank (i.e. without headspace) shall

not exceed a concentration of 20 g/l.

The concentration of the aqueous ClO solution with intermediate storage in a storage tank (i.e. with

headspace) should not exceed a concentration of 3 g/l, to ensure an adequate distance to the explosion

limit (see B.1).
4.3 Impurities and main by-products

Impurities and main by-products of the starting products used for the generation (indicated in A.1.1)

can be found in the in situ generated product in respective proportional concentrations.

Inadequate design, operation and maintenance of reactors can give rise to the formation of chlorine and

traces of chlorate ion and, eventually, the presence of unreacted chlorite, chlorate and/or chlorine (see

[6]); for analysis see 5.2 and A.4.
4.4 Chemical parameters

NOTE For the purpose of this standard, "chemical parameters" are those defined in the EU Directive

98/83/EC of 3 November 1998 (see [1]).

Limits of chemical parameters being potentially present in chlorine dioxide solution have been specified

in the corresponding EN standards of the starting products (indicated in A.1.1).
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5 Test methods
5.1 Sampling

Sampling of chlorine dioxide solutions shall avoid photochemical decompositions, losses by evaporation

of the product and consumption by the glassware and dilution water. Samples shall be taken at the exit

of the reactor or from the storage tank with a sampling tube and the analytical procedures started as

fast as possible.

In order to achieve these objectives the following step by step procedure shall be adopted:

— sampling shall be made in accordance with the general requirements given in ISO 3165 and take

ISO 6206 into account;

— all glassware shall be conditioned immediately before sampling, with the solution under

investigation and this preliminary rinsing sample shall be discarded;

— liquid samples for analytical control shall be introduced directly into the analytical reagent

solutions; the sampling device and procedure shall ensure that the sample is directly contacted

with the analytical reagent without running along the walls of the analytical glassware;

— the sample vessels shall be stoppered, leaving minimal head-space, to store the sample with

reagent mixture;

— at high concentration of chlorine dioxide (>10 g/l) the samples shall be collected in a vessel,

containing water; the analytical result shall be corrected accordingly for the dilution factor;

— titration analysis shall preferably be carried out immediately after sampling and reaction;

— if immediate titration or measurement is not possible, prior to the analytical measurements the

sample plus reagent shall be stored in the dark at low temperature about 5 °C and contact with

ambient air shall be avoided;

— if immediate collection and analysis are not possible, sample the reactor effluent in a 250 ml conical

flask stored on crushed ice and, by introducing the liquid at the bottom of the flask and fill the flask

completely allowing overflow of chlorine dioxide solution.

The volume of the samples shall be adjusted in accordance with the analytical procedure described

hereafter.
5.2 Determination of chlorine dioxide and chlorite concentrations
5.2.1 General

This standard method concerns the determination of chlorine dioxide and chlorite concentrations in

stored solution.
NOTE Other oxidizing agents could interfere with the determination.
5.2.2 Principle
5.2.2.1 General

Phosphate-buffered iodide is first reacted with the chlorine dioxide sample and titrated at pH 7,2 and

subsequently acidified to pH 2 and titration is continued.
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5.2.2.2 With iodometry at pH 7,2
- -
ClO + l ⇒ ClO +1/2 l (1)
2 2 2
and
- -
Cl + 2 l ⇒ l + 2Cl (2)
2 2
5.2.2.3 Subsequent iodometry at pH 2
- - + -
ClO + 4 I + 4 H ⇒ Cl + 2 H O + 2 I (3)
2 2 2

The ratio of equivalents titrated at pH 7,2 and pH 2 shall be 1 to 4 within a deviation of less than 3 %

and indicate at least 97 % of the expected yield. If not appropriate, adjustments and an additional

control as given in 5.2.2.4 may be made, and more selective controls made occasionally according to the

methods described in A.3 and A.4.
5.2.2.4 Chlorite determination

Determination of chlorite concentration after degassing of a separate sample followed by iodometry at

pH 2 (reaction is as in 5.2.2.3 and measure only the chlorite concentration of the sample). The degassing

procedure is given in A.4.1.
5.2.3 Reagents

All reagents shall be of a recognized analytical grade and the water used shall conform to grade 3 in

accordance w
...