EN ISO 25712:2026

Chemicals for the leather tanning industry - Determination of the total content of melamine (ISO 25712:2026)

This document specifies a method for determining the total content (solvent extractable) of melamine in chemicals for the leather tanning industry.
This method requires the use of liquid chromatography (LC) with a triple quadrupole mass spectrometer (MS/MS), an ultraviolet (UV) detector, or diode array detector (DAD) to identify and quantify the melamine.

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)

Le présent document spécifie une méthode de détermination de la teneur totale (extractible au solvant) de mélamine dans les produits chimiques pour l'industrie du tannage du cuir.
Cette méthode exige l'utilisation d'une chromatographie en phase liquide (LC) avec un spectromètre de masse triple quadripoles (MS/MS), un détecteur ultraviolet (UV) ou un détecteur à barrette de diodes (DAD) pour identifier et quantifier la mélamine.

Kemikalije za industrijo strojenja usnja - Določevanje celotne vsebnosti melamina (ISO/FDIS 25712:2026)

General Information

• Status: Not Published
• Publication Date: 28-Apr-2026
• ICS: 59.140.10 - Processes and auxiliary materials
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: CEN/TC 289 - Leather
• Drafting Committee: CEN/TC 289/WG 6 - Test methods for tannery chemicals
• Current Stage: 6055 - CEN Ratification completed (DOR) - Publishing
• Start Date: 24-Apr-2026
• Due Date: 05-Mar-2027
• Completion Date: 24-Apr-2026
• Ref Project: kSIST FprEN ISO 25712:2026 - Chemicals for the leather tanning industry - Determination of the total content of melamine (ISO/FDIS 25712:2026)

Relations

• Consolidated By: ISO 25712:2026 - Chemicals for the leather tanning industry — Determination of the total content of melamine
• Effective Date: 12-Feb-2026

Overview

EN ISO 25712:2026 outlines an internationally recognized method for determining the total (solvent extractable) content of melamine in chemical substances used in the leather tanning industry. Developed jointly by CEN and ISO, this standard stipulates a robust analytical procedure utilizing liquid chromatography (LC), with detection performed using triple quadrupole mass spectrometry (MS/MS), an ultraviolet (UV) detector, or a diode array detector (DAD).

Melamine, a key component in melamine-formaldehyde resins used during retanning, is considered a Substance of Very High Concern (SVHC) in the European Union, drawing increased regulatory attention. Accurate, harmonized quantification of melamine in leather-processing chemicals is essential for safety, regulatory compliance, and quality assurance throughout the supply chain.

Key Topics

• Purpose: Establishes a standardized method for analyzing and quantifying total melamine in chemicals used for leather tanning.
• Scope: Applicable to all chemicals for the leather tanning industry containing or suspected of containing melamine, notably resins and compound products.
• Instrumentation:
  • LC-MS/MS: Delivers high sensitivity and low limits of quantification (LoQ), suitable for strict regulatory needs.
  • LC-UV and LC-DAD: Provides broader accessibility for laboratories, with higher (but still adequate) LoQ.
• Sample Preparation: Involves extraction in an acetonitrile:water mixture, with specific sample homogenization and preparation steps to ensure representative and reproducible results.
• Chromatographic Options:
  • Hydrophilic Interaction Liquid Chromatography (HILIC): Preferred for highly polar melamine, offering optimal separation.
  • Reversed Phase (RP) Chromatography (C8 or C18 columns): Provided as a practical alternative for widespread laboratory compatibility.
• Calculation Methods: Offers formulas for result calculation, both with and without the use of internal standards, to accommodate different laboratory protocols and instrumentation.
• Reporting: Specifies minimum requirements for the test report, including methodology, sample information, detection type, and quantitative result.

Applications

• Regulatory Compliance: Supports adherence to EU and international regulations regarding SVHC substances and reinforces documentation for REACH and other chemical safety frameworks.
• Quality Control in Leather Production: Enables manufacturers and suppliers of tanning chemicals to verify and document melamine levels, reducing risk to end-users and consumers.
• Supply Chain Integrity: Provides a harmonized standard that can be implemented globally, ensuring consistent quality and safety standards across markets.
• Laboratory Accreditation: Facilitates method adoption in both highly equipped (MS/MS) and broadly accessible (UV/DAD) laboratories by offering validated alternatives.
• Research and Development: Assists R&D teams in assessing raw materials or finished chemical formulations during product innovation or improvement projects.

Related Standards

• EN ISO 17025 - Requirements for testing and calibration laboratories.
• EN ISO 2418 - Leather - Chemical, physical and mechanical and fastness tests - Sampling location.
• ISO 4047 - Leather - Determination of Chromium(VI) content.
• REACH Regulation (EC) No. 1907/2006 - Registration, Evaluation, Authorization and Restriction of Chemicals in the EU, referencing SVHC such as melamine.
• IULTCS Methods - International standards for sampling and testing in the leather industry.
• EN ISO 2419 - Leather - Physical and mechanical tests - Sample preparation and conditioning.

By complying with EN ISO 25712:2026, Chemicals for the leather tanning industry - Determination of the total content of melamine, stakeholders across the leather value chain can ensure accurate melamine analysis, uphold regulatory requirements, and maintain the integrity of their products in international markets.

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 25712:2025
01-julij-2025
Kemikalije za industrijo strojenja usnja - Določevanje celotne vsebnosti melamina
(ISO/DIS 25712:2025)
Chemicals for the leather tanning industry - Determination of the total content of
melamine (ISO/DIS 25712:2025)
Chemikalien für die Ledergerbereiindustrie - Bestimmung des Gesamtmelamingehalts
(ISO/DIS 25712:2025)
Produits chimiques pour l'industrie du tannage du cuir - Détermination de la teneur totale
en mélamine (ISO/DIS 25712:2025)
Ta slovenski standard je istoveten z: prEN ISO 25712
ICS:
59.140.10 Postopki in pomožni materiali Processes and auxiliary
materials
71.040.50 Fizikalnokemijske analitske Physicochemical methods of
metode analysis
oSIST prEN ISO 25712:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 25712:2025
oSIST prEN ISO 25712:2025
DRAFT
International
Standard
ISO/DIS 25712
IUC 443
IULTCS
Chemicals for the leather tanning
Secretariat: ISO
industry – Determination of the
total content of melamine
Voting begins on:
2025-06-02
ICS: 59.140.10
Voting terminates on:
2025-08-25
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
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.
Reference number
ISO/DIS 25712:2025(en)
IUC 443:2025(en)
oSIST prEN ISO 25712:2025
DRAFT
ISO/DIS 25712:2025(en)
International
Standard
ISO/DIS 25712
IUC 443
IULTCS
Chemicals for the leather tanning
Secretariat: ISO
industry – Determination of the
total content of melamine
Voting begins on:
ICS: 59.140.10
Voting terminates on:
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Reference number
Published in Switzerland ISO/DIS 25712:2025(en)
IUC 443:2025(en)
ii
oSIST prEN ISO 25712:2025
ISO/DIS 25712:2025(en)
IUC 443:2025(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 . 6
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
oSIST prEN ISO 25712:2025
ISO/DIS 25712:2025(en)
IUC 443:2025(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
oSIST prEN ISO 25712:2025
ISO/DIS 25712:2025(en)
IUC 443:2025(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 .

v
oSIST prEN ISO 25712:2025
oSIST prEN ISO 25712:2025
ISO/DIS 25712:2025(en)
DRAFT International Standard
IUC 443:2025(en)
Chemicals for the leather tanning industry – Determination of
the total content of melamine
1 Scope
This document specifies a method for determining the total content (solvent extractable) of melamine in
chemicals for the leather tanning industry.
This method requires the use of liquid chromatography (LC) with a triple quadrupole mass spectrometer
(MS/MS), an ultraviolet (UV) detector, or diode array detector (DAD) to identify and quantify the melamine.
2 Normative references
There are no normative references in this document.
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 Principle
The chemical sample is extracted in a 50:50 (v/v) mixture of acetonitrile and water. Subsequently, an aliq
...