SIST EN ISO 25712:2026

SLOVENSKI STANDARD
01-julij-2026
Kemikalije za industrijo strojenja usnja - Ugotavljanje celotne vsebnosti melamina
(ISO 25712:2026)
Chemicals for the leather tanning industry - Determination of the total content of
melamine (ISO 25712:2026)
Chemikalien für die Ledergerbereiindustrie - Bestimmung des Gesamtmelamingehalts
(ISO 25712:2026)
Produits chimiques pour l'industrie du tannage du cuir - Détermination de la teneur totale
en mélamine (ISO 25712:2026)
Ta slovenski standard je istoveten z: EN ISO 25712:2026
ICS:
59.140.10 Postopki in pomožni materiali Processes and auxiliary
materials
71.040.50 Fizikalnokemijske analitske Physicochemical methods of
metode analysis
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 25712
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2026
EUROPÄISCHE NORM
ICS 59.140.10
English Version
Chemicals for the leather tanning industry - Determination
of the total content of melamine (ISO 25712:2026)
Produits chimiques pour l'industrie du tannage du cuir Chemikalien für die Ledergerbereiindustrie -
- Détermination de la teneur totale en mélamine (ISO Bestimmung des Gesamtmelamingehalts (ISO
25712:2026) 25712:2026)
This European Standard was approved by CEN on 24 April 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 ISO 25712:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 25712:2026) has been prepared by Technical Committee ISO/IULTCS
"International Union of Leather Technologists and Chemists Societies" in collaboration with Technical
Committee CEN/TC 289 “Leather” the secretariat of which is held by UNI.
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 October 2026, and conflicting national standards shall
be withdrawn at the latest by October 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.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, 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.
Endorsement notice
The text of ISO 25712:2026 has been approved by CEN as EN ISO 25712:2026 without any modification.

International
Standard
ISO
IUC 443
First edition
Chemicals for the leather tanning
2026-04
industry — Determination of the
total content of melamine
Produits chimiques pour l'industrie du tannage du cuir —
Détermination de la teneur totale en mélamine
Reference number
ISO 25712:2026(en)
IUC 443:2026(en) © ISO 2026
ISO 25712:2026(en)
IUC 443:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 25712:2026(en)
IUC 443:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 1
6 Reagents . 2
7 Sampling and sample preparation . 4
8 Procedure . 4
8.1 Extraction .4
8.2 Instrumental analysis .4
9 Expression of results . 5
9.1 Calculation without internal standard .5
9.2 Calculation with internal standard .5
10 Precision . 5
11 Test report . 6
Annex A (informative) Chromatographic analysis operating parameters for LC-MS/MS . 7
Annex B (informative) Chromatographic analysis operating parameters for LC-UV or LC-DAD . 9
Annex C (informative) Precision . 10
Bibliography .11

iii
ISO 25712:2026(en)
IUC 443:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to further
the advancement of leather science and technology. IULTCS has three Commissions, which are responsible
for establishing international methods for the sampling and testing of leather. ISO recognizes IULTCS as an
international standardizing body for the preparation of test methods for leather.
This document was prepared by the Chemical Test Commission of the International Union of Leather
Technologists and Chemists Societies (IUC Commission, IULTCS), in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO 25712:2026(en)
IUC 443:2026(en)
Introduction
This document includes a procedure for analysing melamine in leather tanning chemicals using liquid
chromatography (LC) equipment.
In the leather industry, melamine can be present as a residual monomer in resins based on the polymerisation
of melamine, where melamine-formaldehyde resin is the more typical. This type of resin is present in
chemical products such as melamine-formaldehyde resin or compound products and is used in the retanning
stage of the tanning process.
At present, the official European Chemicals Agency (ECHA) classification recognized in the European Union
(EU) for melamine is the following:
[1]
— substance of very high concern (SVHC) and included in the candidate list for authorisation ;
[2]
— suspected to be Carcinogenic ;
[2]
— under assessment as Persistent, Bioaccumulative and Toxic ;
[2]
— under assessment as Endocrine Disrupting .

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ISO 25712:2026(en)
International Standard
IUC 443:2026(en)
Chemicals for the leather tanning industry — Det
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