prEN 16004

• Abstract:

  This European Standard is applicable to magnesium oxide used for treatment of water intended for human consumption. It describes the characteristics of magnesium oxide and specifies the requirements and the corresponding test methods for magnesium oxide. It gives information on its use in water treatment.

• Status: Not Published
• Publication Date: 29-Jun-2028
• 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: 4020 - Submission to enquiry - Enquiry
• Start Date: 01-Oct-2026
• Due Date: 19-Mar-2027
• Completion Date: 01-Oct-2026
• Ref Project: oSIST prEN 16004:2026 - Chemicals used for treatment of water intended for human consumption - Magnesium oxide

• Revises: EN 16004:2011 - Chemicals used for treatment of water intended for human consumption - Magnesium oxide
• Effective Date: 29-Apr-2026

prEN 16004 is a draft European Standard from CEN for magnesium oxide used in the treatment of water intended for human consumption. It specifies the product’s characteristics, purity criteria and test methods, and it also gives practical information on use, labelling, transport and storage for suppliers, laboratories and water-treatment users.

What does prEN 16004 specify?

prEN 16004 applies to magnesium oxide used for treating water intended for human consumption. The document describes the product, sets purity and chemical limits, and links those limits to test methods and handling information.

The standard is organized into:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Description
• Clause 4 Purity criteria
• Clause 5 Test methods
• Clause 6 Labelling - Transportation - Storage
• Annex A, which gives general information for users

Annex	What it covers
Annex A	General information on magnesium oxide, including origin, drinking-water impact, use, handling and emergency procedures

The introduction also notes that conformity with prEN 16004 does not by itself mean the product is approved for use in every EU or EFTA country, because national regulation and control still apply.

What are the key requirements of prEN 16004?

prEN 16004 is mainly a product specification. For a buyer, supplier or laboratory, the practical task is to verify the product identity, composition, impurities, trace metals, sampling and marking against the clauses and tables.

Product identity and form

Clause 4.1 identifies the material as magnesium oxide that may contain magnesium dihydroxide. Clause 4.2 says it is supplied as granular material in different particle-size ranges. In practice, this means the grade on the market is not a single pure chemical, but a commercial product with defined forms and composition.

Physical and chemical behaviour

Clause 4.3 describes the product as a grey, round granular material and gives its density, bulk density and solubility characteristics. Clause 4.4 says it acts as an alkali in water and reacts with carbon dioxide and water to form magnesium hydrogen carbonate. This matters for dosing, mixing and how the product changes water chemistry in service.

Commercial composition

Clause 5.2 and Table 1 set the composition limits for the commercial product, including the magnesium oxide content and the loss on ignition (LoI). In practice, this is the first check that a delivered batch has the expected strength and moisture/carbonate content.

Impurities and chemical parameters

Clause 5.3 and Table 2 limit common mineral impurities such as calcium compounds, silicon dioxide, aluminium oxide and iron oxide. Clause 5.4 and Table 3 limit chemical parameters such as antimony, arsenic, cadmium, chromium, lead, mercury, nickel and selenium. These limits are the main quality and drinking-water protection checks for procurement and incoming inspection.

Sampling and analysis

Clause 6 directs users to ISO 3165, ISO 6206 and EN 12485 for sampling and analytical work. That means conformity should be checked with the referenced procedures rather than with an informal plant method.

Delivery, marking and storage

Clause 7 allows delivery in bags, containers or as bulk material. It requires the product to be marked with the product description, trade name and grade, net mass, supplier or manufacturer name and address, and a statement of conformity to EN 16004. The product is to be kept dry and away from acids.

Use information

Annex A.3 says magnesium oxide products are used to adjust pH and hardness, neutralize mineral acids and operate in filters. Annex A.2 relates product purity to drinking-water impact and points to the Drinking Water Directive for limit values.

What terms does prEN 16004 define?

prEN 16004 uses product and control terms that matter in practice when specifying, buying and testing the material.

• Magnesium oxide - In this standard, the product can include magnesium dihydroxide, so the commercial material is not limited to a single chemical form.
• Loss on ignition (LoI) - The mass lost on heating, used here as a control on water and carbon dioxide content in the product.
• Dry substance - The basis used for composition and chemical-parameter limits after removing moisture.
• CAS Registry Number - The Chemical Abstracts Service identifier used for product identification.
• EINECS reference - The European Inventory of Existing Commercial Chemical Substances identifier used for identification.
• REACH - The EU chemicals regulation cited for classification and market responsibilities.
• Parametric values - Drinking-water limit values referenced in Annex A.2 when comparing product impact with water-quality limits.

Who uses prEN 16004?

prEN 16004 is used by manufacturers and suppliers of water-treatment chemicals, by laboratories that sample and test magnesium oxide, and by water utilities or treatment-plant operators that use the product for pH and hardness adjustment or for neutralizing mineral acids. It is also useful for buyers and quality managers who need a purchase specification, delivery checks and conformity marking.

What changed in prEN 16004 from the previous edition?

prEN 16004 will supersede EN 16004:2011. The draft notes editorial and technical changes to the product naming, a corrected density value, updated notes in Clause 4.4 and Clause 6.2, a new Annex A.2 on drinking-water impact, revised particle-size information in Annex A.3, the addition of EN 12902 as a reference method, an update to the Drinking Water Directive in the bibliography, and the addition of magnesium dihydroxide to the product description and Table 1.

Which standards are used with prEN 16004?

Reference	What it contributes
EN 12485	Test methods used for analysis and laboratory sample preparation
ISO 3165	General recommendations for sampling chemical products for industrial use
ISO 6206	Sampling vocabulary for industrial chemical products
EN 12902	Method cited in Annex A for determining particle size range

What does the prEN 16004 document contain?

prEN 16004 contains the product description, the purity criteria tables, the sampling and analysis rules, and the delivery, labelling and storage instructions. It also includes an informative annex with general information on origin, use, drinking-water impact, particle-size ranges, safe handling and emergency procedures. The bibliography links the standard to the Drinking Water Directive, REACH, classification and labelling rules, and EN 12902 for particle-size testing.

SLOVENSKI STANDARD
01-december-2026
Kemikalije, ki se uporabljajo za pripravo pitne vode - Magnezijev oksid
Chemicals used for treatment of water intended for human consumption - Magnesium
oxide
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch -
Magnesiumoxid
Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation
humaine - Oxyde de magnésium
Ta slovenski standard je istoveten z: prEN 16004
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
October 2026
ICS Will supersede EN 16004:2011
English Version
Chemicals used for treatment of water intended for human
consumption - Magnesium oxide
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Oxyde de menschlichen Gebrauch - Magnesiumoxid
magnésium
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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16004:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Description . 5
3.1 Identification . 5
3.2 Commercial forms . 6
3.3 Physical properties . 6
3.4 Chemical properties . 6
4 Purity criteria . 6
4.1 General. 6
4.2 Composition of commercial product . 7
4.3 Impurities and main by-product . 7
4.4 Chemical parameters. 7
5 Test methods . 8
5.1 Sampling . 8
5.2 Analyses. 8
6 Labelling - Transportation - Storage . 8
6.1 Means of delivery . 8
6.2 Risk and safety labelling according to the EU directives . 8
6.3 Transportation regulations and labelling . 8
6.4 Marking . 9
6.5 Storage . 9
Annex A (informative) General information on magnesium oxide. 10
A.1 Origin . 10
A.2 Impact of commercial products on drinking water quality . 10
A.3 Use . 11
A.4 Rules for safe handling and use . 11
A.5 Emergency procedures . 11
Bibliography . 12
European foreword
This document (prEN 16004:2026) 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 16004:2011.
to EN 16004:2011:
a) in 3.1.2 magnesite as a synonym or common name was corrected to magnesia and periclase, and
correcting the term in A.1.1 to periclase;
b) in 3.3.2 Density was corrected to 3,6 g/cm at 20 °C;
c) in 4.4 adjusting the NOTE to Table 3;
d) in 6.2 Note to 4) including [4] in direct reference to the Bibliography;
e) inserting a new “A.2 Impact of commercial products on drinking water quality” with a new
“Table A.1 Maximum impact of Magnesium oxide on chemical parameter contents of water. Drinking
water limit values based on Drinking Water Directive.”;
f) in A.3.3 amending and reducing Table A.2;
g) in A.3.3 including EN 12902 as reference method for the determination of the particle size range, and
including it in Bibliography;
h) in the Bibliography, the older Drinking Water Directive was replaced with the revised one;
i) magnesium dihydroxide has been added in 3.1 and followings to comply with products on the
market, and Table 1.
Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused
by the product covered by this Standard:
— this 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;
— 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 the 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.
1 Scope
This document is applicable to magnesium oxide used for treatment of water intended for human
consumption. It describes the characteristics of magnesium oxide with magnesium dihydroxide and
specifies the requirements and the corresponding test methods for magnesium oxide products. It gives
information on its use in water treatment.
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 12485, Chemicals used for treatment of water intended for human consumption - Calcium carbonate,
high-calcium lime, half-burnt dolomite, magnesium oxide, calcium magnesium carbonate and dolomitic lime
- Test methods
ISO 3165, Sampling of chemical products for industrial use — Safety in sampling
ISO 6206, Chemical products for industrial use — Sampling — Vocabulary
3 Terms and definitions
No terms and definitions are listed in this document.
4 Description
4.1 Identification
4.1.1 Genera
...