EN 15077:2026

Chemicals used for treatment of swimming pool and spas water - Sodium hypochlorite

This document is applicable to sodium hypochlorite used directly or for the production of formulations for treating swimming pool and spas water. It describes the characteristics of sodium hypochlorite and specifies the requirements and the corresponding test methods for sodium hypochlorite. It gives information on its use for treating swimming pool and spas water.

Produkte zur Aufbereitung von Schwimm- und Badebeckenwasser - Natriumhypochlorit

Dieses Dokument ist anwendbar für Natriumhypochlorit, das direkt zur Aufbereitung von Schwimm- und Badebeckenwasser oder zum Herstellen von Zubereitungen für diesen Zweck verwendet wird. Es beschreibt die Eigenschaften von Natriumhypochlorit und legt die Anforderungen sowie die entsprechenden Prüfverfahren für Natriumhypochlorit fest. Es enthält Angaben zu dessen Anwendung bei der Aufbereitung von Schwimm- und Badebeckenwasser.

Produits chimiques utilisés pour le traitement de l'eau des piscines et des spas - Hypochlorite de sodium

Le présent document est applicable à l’hypochlorite de sodium utilisé directement ou pour préparer des formulations pour traiter l’eau des piscines et des spas. Il décrit les caractéristiques de l’hypochlorite de sodium et spécifie les exigences et les méthodes d’essais correspondantes applicables à l’hypochlorite de sodium. Il informe également sur son utilisation dans le cas du traitement de l’eau des piscines et des spas.

Kemikalije, ki se uporabljajo za pripravo bazenske vode - Natrijev hipoklorit

Ta dokument se uporablja za natrijev hipoklorit, ki se uporablja neposredno ali za proizvodnjo formulacij za obdelavo vode v bazenih in zdraviliščih. Opisuje lastnosti natrijevega hipoklorita ter določa zahteve in ustrezne preskusne metode za natrijev hipoklorit. Ponuja informacije o njegovi uporabi za obdelavo vode v bazenih in zdraviliščih.

General Information

• Status: Published
• Publication Date: 17-Mar-2026
• 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: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 18-Mar-2026
• Due Date: 15-May-2026
• Completion Date: 18-Mar-2026
• Ref Project: SIST EN 15077:2026 - Chemicals used for treatment of swimming pool water - Sodium hypochlorite

Relations

• Replaces: EN 15077:2013 - Chemicals used for treatment of swimming pool water - Sodium hypochlorite
• Effective Date: 07-Feb-2024
• Refers: EN 901:2024 - Chemicals used for treatment of water intended for human consumption - Sodium hypochlorite
• Effective Date: 15-Apr-2026

Overview

prEN 15077 (FprEN 15077) is a CEN draft European standard that specifies the characteristics, purity criteria, test methods and handling information for sodium hypochlorite used directly or for producing formulations to treat swimming pool and spa water. It updates and will supersede EN 15077:2013 and aligns labelling, transportation and storage guidance with current safety and classification rules. The standard applies to aqueous sodium hypochlorite solutions with active (available) chlorine up to about 18% by mass.

Key topics and technical requirements

• Product description and identification: chemical names (NaClO), CAS (7681-52-9), common names (liquid bleach), physical and chemical properties (clear yellow‑green solution, pH > 11, density 1.13–1.30 g/ml at 20 °C).
• Concentration and composition: supplied solutions up to 18% active chlorine; common concentrated products ≥12% active chlorine. Manufacturer’s declared concentration must be met or exceeded at delivery.
• Purity and impurities: limits for trace metals and by-products expressed per mg/kg of available chlorine (examples: arsenic, lead, cadmium, chromium, mercury, nickel, selenium) and limits on by-products such as sodium chlorate (not to exceed 5.4% mass fraction of available chlorine) and sodium bromate.
• Test methods: sampling and analysis referenced to EN 901.
• Labelling and hazard communication: GHS hazard statements for products ≥5% active chlorine (H314, H400, EUH031) and requirement for precautionary statements and extended SDS.
• Transportation and marking: UN 1791; ADR/RID Class 8, packing group II; users must be aware of incompatibilities during transport; means of delivery must be clearly marked (name/type displayed at viewing height).
• Storage and stability: protect from light and heat, store cool in appropriate containers (PE, PVC-GFR or rubber-lined/ plastic-coated steel); decomposition reduces active chlorine (example: ~1 g/L per day at 20 °C) and increases chlorates.

Practical applications and users

• Intended for manufacturers, formulators, pool operators, water treatment suppliers, transporters and regulatory bodies dealing with chemicals for pool and spa water treatment.
• Helps ensure product quality, safe handling, compliant labelling/transport, and consistent dosing for effective disinfection.
• Useful for procurement specifications, safety data sheets, quality control labs and compliance checks.

Related standards and references

• Normative reference: EN 901 (sampling and analysis for sodium hypochlorite).
• Mentions EU biocidal regulation (Regulation (EU) No 528/2012) and classification criteria (Regulation (EC) No 1272/2008).
• Supersedes EN 15077:2013 when adopted.

Keywords: sodium hypochlorite, swimming pool water treatment, pool chemicals, EN 15077, CEN, sodium chlorate, active chlorine, storage and labelling.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2026
Kemikalije, ki se uporabljajo za pripravo bazenske vode - Natrijev hipoklorit
Chemicals used for treatment of swimming pool water - Sodium hypochlorite
Produkte zur Aufbereitung von Schwimm- und Badebeckenwasser - Natriumhypochlorit
Produits chimiques utilisés pour le traitement de l’eau des piscines - Hypochlorite de
sodium
Ta slovenski standard je istoveten z: EN 15077:2026
ICS:
13.060.25 Voda za industrijsko uporabo Water for industrial use
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.

EN 15077
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2026
EUROPÄISCHE NORM
ICS 71.100.80 Supersedes EN 15077:2013
English Version
Chemicals used for treatment of swimming pool and spas
water - Sodium hypochlorite
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Schwimm- und
des piscines et des spas - Hypochlorite de sodium Badebeckenwasser - Natriumhypochlorit
This European Standard was approved by CEN on 26 January 2026.

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, 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, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15077:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Description . 6
4.1 Identification . 6
4.1.1 Chemical name . 6
4.1.2 Synonym or commons name . 6
4.1.3 Relative molecular mass . 6
4.1.4 Empirical formula . 6
4.1.5 Chemical formula . 6 ®
4.1.6 CAS-Registry Number  . 6
4.1.7 EINECS reference . 7
4.2 Commercial form . 7
4.3 Physical properties . 7
4.3.1 Appearance and odour . 7
4.3.2 Density . 7
4.3.3 Solubility in water . 7
4.3.4 Vapour pressure . 7
4.3.5 Boiling point at 100 kPa . 7
4.3.6 Crystallization and freezing point . 7
4.3.7 Specific heat . 7
4.3.8 Viscosity (dynamic) . 7
4.3.9 Critical temperature . 7
4.3.10 Critical pressure . 7
4.3.11 Physical hardness . 7
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 . 8
5.4 Chemical parameters. 9
6 Test methods . 9
7 Labelling – Transportation - Storage . 9
7.1 Means of delivery . 9
7.2 Labelling . 10
7.3 Transportation regulations and labelling . 11
7.4 Marking . 11
7.5 Storage . 11
7.5.1 General. 11
7.5.2 Long-term stability . 11
7.5.3 Storage incompatibilities . 11
Annex A (informative) General information on sodium hypochlorite . 12
A.1 Origin . 12
A.1.1 Raw materials . 12
A.1.2 Manufacturing process . 12
A.2 Use . 12
A.2.1 Function . 12
A.2.2 Form in which the product is used . 12
A.2.3 Treatment dose . 12
A.2.4 Means of application. 12
A.2.5 Secondary effects . 12
A.2.6 Removal of excess product . 12
A.3 Factors influencing active chlorine decay and chlorate formation [4] . 13
A.3.1 Example shape of curves presenting the active chlorine decay vs. temperature and storage
time . 13
A.3.2 Example shape of curves presenting the chlorate formation vs. time and temperature . 14
A.3.3 Influence of initial active concentration vs. storage . 15
Annex B (normative) General rules relating to safety . 16
B.1 Rules for safe handling and use . 16
B.2 Emergency procedures . 16
B.2.1 First aid . 16
B.2.2 Spillage . 16
B.2.3 Fire . 16
Bibliography . 17

European foreword
This document (EN 15077:2026) 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 September 2026, and conflicting national standards shall
be withdrawn at the latest by September 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 15077:2013.
a) modification of 7.3 on transportation regulations and labelling, adding the sentence “The user shall
be aware of the incompatibilities between transported products.”;
b) modification of 7.4 on marking, adding the note “at least the name and type of the product shall be
clearly marked or displayed at viewing height on the means of delivery”.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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, 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, Türkiye 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 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) 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 document does not confer or imply acceptance or approval of the product in any of
the Member States of the EU or EFTA. Local regulations and requirements can apply.
NOTE 2 This product is a biocide. At
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