FprEN 889

• Abstract:

  This document is applicable to iron (II) sulfate heptahydrate and iron (II) sulfate monohydrate used for treatment of water intended for human consumption. It describes the characteristics of iron (II) sulfate heptahydrate and monohydrate, specifies the requirements and the corresponding analytical methods and gives information on their use in water treatment. It also specifies the rules relating to safe handling (Annex B) and describes the use of iron (II) sulfate (Annex A).

• Status: Not Published
• Publication Date: 09-Dec-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: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 29-Jun-2026
• Due Date: 08-Sep-2026
• Completion Date: 29-Jun-2026
• Ref Project: oSIST prEN 889:2025 - Chemicals used for treatment of water intended for human consumption - Iron (II) sulfate

• Referred By: EN ISO 17871:2020 - Gas cylinders - Quick-release cylinder valves - Specification and type testing (ISO 17871:2020)
• Effective Date: 28-Jan-2026
• Revises: EN 889:2023 - Chemicals used for treatment of water intended for human consumption - Iron (II) sulfate
• Effective Date: 04-Dec-2024

Overview

FprEN 889 is a draft European Standard developed by CEN (the European Committee for Standardization) that specifies the requirements for iron (II) sulfate heptahydrate and iron (II) sulfate monohydrate when used in the treatment of water intended for human consumption. The standard covers product characteristics, purity criteria, test methods, handling and safety, and provides guidance on appropriate use in water treatment processes. This ensures uniform quality and safety for chemicals used in drinking water treatment across Europe.

Iron (II) sulfate, also known as ferrous sulfate, is widely used as a coagulant in water purification. This standard supports compliance with EU regulations for potable water and aligns with the Drinking Water Directive (EU) 2020/2184.

Key Topics

• Product Forms

  • Iron (II) sulfate heptahydrate (damp or free-flowing crystals)
  • Iron (II) sulfate monohydrate (dry crystals)
  • Iron (II) sulfate solution

• Physical and Chemical Properties

  • Appearance: light green or grey crystals, dark green solution
  • Density and solubility specifications
  • Acidic and reducing chemical nature
  • Typical impurity limits (arsenic, cadmium, chromium, etc.)

• Purity and Quality Criteria

  • Defines grades and types with specific allowable impurity levels
  • Sets minimum iron (II) sulfate content:
    • Heptahydrate: at least 82% FeSO₄·7H₂O
    • Monohydrate: at least 82% FeSO₄·H₂O
  • Maximum concentrations for elements like lead, mercury, and nickel

• Test and Analytical Methods

  • Referenced methods for sampling and chemical analysis (EN 17215)
  • Ensures consistent approach to quality assurance in water treatment

• Labelling, Transportation, and Storage

  • Requirements for safe labelling according to EU directives
  • Guidelines for packaging, transport classification, and storage conditions
  • Emphasis on preventing product contamination and degradation

• Safety and Handling

  • Precautions for exposure, first aid, and spillage
  • Product is non-combustible, mildly acidic
  • Incompatibility with strong oxidizers and materials reactive with acids

Applications

• Municipal Water Treatment
  Iron (II) sulfate is primarily used as a coagulant in the purification of drinking water. It effectively assists in the removal of suspended solids, color, and organic matter, thereby improving water clarity and quality.

• Coagulation Processes
  When added to water, iron (II) sulfate facilitates coagulation and the subsequent formation and removal of precipitates. For best results, oxidation to the iron (III) state is often utilized, followed by sedimentation or filtration.

• Compliance and Traceability
  Use of products that meet FprEN 889 ensures proper control over contaminants, helps utilities meet drinking water quality standards, and supports traceability in procurement and application.

• Industrial and Emergency Water Treatment
  Beyond municipal use, iron (II) sulfate can be applied in temporary or emergency water treatment setups where rapid clarification is required.

Related Standards

• EN 17215
  Analytical methods for iron-based coagulants in water treatment, referenced for testing and quality control.

• Directive (EU) 2020/2184
  Drinking Water Directive - sets parametric values for substances in water intended for human consumption.

• Regulation (EC) No 1272/2008 (CLP Regulation)
  Classification, labelling, and packaging rules for chemicals and mixtures (including safety data sheet requirements).

Keywords: iron(II) sulfate, iron sulfate, water treatment chemicals, drinking water standards, CEN, EN 889, coagulant, water purification, water quality, safety in water treatment, chemical handling, regulatory compliance.

By adhering to FprEN 889, water treatment facilities can ensure the consistent application of high-quality chemicals, optimize treatment processes, and contribute to the delivery of safe and clean drinking water to consumers.

SLOVENSKI STANDARD
01-oktober-2025
Kemikalije, ki se uporabljajo za pripravo pitne vode - Železov (II) sulfat
Chemicals used for treatment of water intended for human consumption - Iron (II) sulfate
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Eisen(II)sulfat
Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation
humaine - Sulfate de fer (II)
Ta slovenski standard je istoveten z: prEN 889
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
prEN 889
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2025
ICS 71.100.80 Will supersede EN 889:2023
English Version
Chemicals used for treatment of water intended for human
consumption - Iron (II) sulfate
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Sulfate de fer menschlichen Gebrauch - Eisen(II)sulfat
(II)
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, Türkiye 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 889:2025 E
worldwide for CEN national Members.

prEN 889:2025 (E)
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 names . 6
4.1.2 Synonym or common names . 6
4.1.3 Relative molecular mass . 7
4.1.4 Empirical formula . 7
4.1.5 Chemical formula . 7
4.1.6 CAS Registry Number . 7
4.1.7 EINECS reference . 7
4.2 Commercial forms . 7
4.3 Physical properties . 8
4.3.1 Appearance . 8
4.3.2 Density . 8
4.3.3 Solubility (in water) . 8
4.3.4 Vapour pressure . 8
4.3.5 Boiling point at 100 kPa . 8
4.3.6 Melting point . 8
4.3.7 Specific heat . 8
4.3.8 Viscosity (dynamic) . 8
4.3.9 Critical temperature . 8
4.3.10 Critical pressure . 9
4.3.11 Physical hardness . 9
4.4 Chemical properties . 9
5 Purity criteria . 9
5.1 General . 9
5.2 Composition of commercial product . 9
5.3 The grade of the product . 9
5.4 The type of the product . 10
6 Test methods . 10
6.1 Sampling . 10
6.2 Analyses . 11
7 Labelling - Transportation - Storage . 11
7.1 Means of delivery . 11
7.2 Risk and safety labelling according to the EU Directives . 11
7.3 Transportation regulations and labelling . 12
7.4 Marking . 12
7.5 Storage . 12
7.5.1 Long term stability . 12
prEN 889:2025 (E)
7.5.2 Storage incompatibilities . 13
Annex A (informative) General information on iron (II) sulfate . 14
A.1 Origin . 14
A.1.1 Raw materials . 14
A.1.2 Manufacturing process . 14
A.2 Quality of commercial product . 14
A.3 Use . 16
A.3.1 Function . 16
A.3.2 Form in which it is used. 16
A.3.3 Treatment dose . 16
A.3.4 Means of application . 16
A.3.5 Secondary effects . 16
A.3.6 Removal of excess product . 17
Annex B (normative) General rules relating to safety . 18
B.1 General rules relating to safety . 18
B.2 Emergency procedures . 18
B.2.1 First aid . 18
B.2.2 Spillage . 18
B.2.3 Fire . 18
Bibliography . 19

prEN 889:2025 (E)
European foreword
This document (prEN 889:2025) 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 889:2023.
prEN 889:2025 includes the following significant technical changes with respect to EN 889:2023:
— update of the information related to limit values in Table 2 and Annex A.

prEN 889:2025 (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:
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.

prEN 889:2025 (E)
1 Scope
This document is applicable to iron (II) sulfate heptahydrate and iron (II) sulfate monohydrate used for
treatment of water intended for human consumption. It describes the characteristics of iron (II) sulfate
heptahydrate and monohydrate, specifies the requirements and the corresponding analytical methods
and gives information on their use in water treatment. It also determines the rules relating to safe
handling (Annex B) and use of iron (II) sulfate (Annex A).
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 17215, Chemicals used for treatment of water intended for human consumption — Iron-based
coagulants — Analytical methods
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Description
4.1 Identification
4.1.1 Chemical names
a) Iron (II) sulfate heptahydrate
b) Iron (II) sulfate monohydrate
c) Iron (II) sulfate solution
4.1.2 Synonym or common names
a) Ferrous sulfate, iron vitriol, copperas, green salt
b) Ferrous sulfate, monohydrate
c) Ferrous sulfate, solution
prEN 889:2025 (E)
4.1.3 Relative molecular mass
a) 278,02 g/mol
b) 169,96 g/mol
c) 151,94 g/mol
4.1.4 Empirical formula
a) FeSO ·7H O
4 2
b) FeSO ·H O
4 2
c)
...