EN ISO 17234-2:2011

Leather - Chemical tests for the determination of certain azo colorants in dyed leathers - Part 2: Determination of 4-aminoazobenzene (ISO 17234-2:2011)

ISO 17234-2:2011 is supplementary to ISO 17234-1 and describes a special procedure to detect the use of certain azo colorants in commodities, which can release 4-aminoazobenzene. The procedure also detects 4-aminoazobenzene (Solvent Yellow 1) which is already available as free amine in commodities without reducing pretreatment.
Azo colorants that are able to form 4-aminoazobenzene generate, under the conditions of ISO 17234‑1, the amines aniline and 1,4-phenylenediamine. The presence of these 4-aminoazobenzene colorants cannot be reliably ascertained without additional information (e.g. the chemical structure of the colorant used) or without a special procedure.

Leder - Chemische Prüfungen zur Bestimmung bestimmter Azofarbstoffe in gefärbten Ledern - Teil 2: Bestimmung von 4-Aminoazobenzol (ISO 17234-2:2011)

Dieser Teil von ISO 17234 stellt eine Ergänzung zu ISO 17234-1 dar und beschreibt ein spezielles Verfahren,
um die Verwendung von bestimmten Azofarbstoffen, die 4-Aminoazobenzol freisetzen können, in Bedarfsgegenständen
zu ermitteln. Das Verfahren detektiert auch 4-Aminoazobenzol (Solvent Yellow 1), das bereits als
freies Amin ohne eine reduzierende Vorbehandlung in Bedarfsgegenständen vorhanden ist.
Azofarbstoffe, die in der Lage sind 4-Aminoazobenzol abzuspalten, erzeugen unter den Bedingungen nach
ISO 17234-1 die Amine Anilin und 1,4-Phenylendiamin. Die Anwesenheit dieser 4-Aminoazobenzol-Farbstoffe
kann nicht ohne weitere Informationen (z. B. die chemische Struktur des verwendeten Farbstoffes) oder ohne
ein spezielles Verfahren zuverlässig ermittelt werden.
Die Verwendung von bestimmten Azofarbstoffen, die durch reduktive Spaltung der Azogruppe(n) eines oder
mehrere der anderen aromatischen Amine freisetzen können, die in Anhang XVII der Verordnung (EG)
Nr. 1907/2006 des Europäischen Parlaments und des Rates zur Registrierung, Bewertung, Zulassung und
Beschränkung chemischer Stoffe (REACH) gelistet sind, mit Ausnahme von 4-Aminoazobenzol, kann mit
diesem Verfahren nicht quantitativ bestimmt werden.

Cuir - Essais chimiques pour le dosage de certains colorants azoïques dans les cuirs teints - Partie 2: Dosage du 4-aminoazobenzène (ISO 17234-2:2011)

L'ISO 17234-2:2011 est complémentaire à l'ISO 17234-1 et décrit un mode opératoire spécial permettant de détecter l'utilisation dans des produits de certains colorants azoïques, qui peuvent libérer du 4-aminoazobenzène. Le mode opératoire détecte également le 4-aminoazobenzène (Solvent Yellow 1) qui est déjà disponible comme amine libre dans les produits sans prétraitement de réduction.
Les colorants azoïques qui sont capables de former du 4-aminoazobenzène génèrent, dans les conditions de l'ISO 17234-1, les amines aniline et 1,4-phénylènediamine. La présence de ces colorants 4-aminoazobenzène ne peut pas être établie de façon fiable sans information complémentaire (par exemple la structure chimique du colorant utilisé) ou sans un mode opératoire spécial.

Usnje - Kemični preskusi za določevanje določenih azo barvil na barvanem usnju - 2. del: Določevanje 4-aminoazobenzena (ISO 17234-2:2011)

Ta del ISO 17234 dopolnjuje ISO 17234-1 in opisuje poseben postopek za odkrivanje uporabe nekaterih azobarvil v proizvodih, ki lahko sproščajo 4-aminobenzen. Postopek zaznava tudi 4-aminoazobenzen (Solvent Yellow 1), ki je v proizvodih že razpoložljiv kot prosti amin brez predhodne reducirne obdelave. Iz azobarvil, ki lahko tvorijo 4-aminoazobenzen, lahko v okoliščinah, navedenih v ISO 17234-1, nastajata amin anilin in 1,4-fenilendiamin. Prisotnosti teh 4-aminoazobenzenskih barvil ni mogoče zanesljivo dokazati brez dodatnih informacij (npr. kemijske strukture uporabljenega barvila) ali brez posebnega postopka. S to metodo ni mogoče količinsko določati uporabe nekaterih azobarvil, ki lahko z redukcijsko cepitvijo svojih azoskupin sproščajo enega ali več drugih aromatskih aminov, navedenih v Prilogi XVII Uredbe (ES) Evropskega parlamenta in Sveta št. 1907/2006 o registraciji, evalvaciji, avtorizaciji in omejevanju kemikalij(REACH), razen 4-aminoazobenzena.

General Information

• Status: Published
• Publication Date: 14-Mar-2011
• Withdrawal Date: 29-Sep-2011
• ICS: 59.140.30 - Leather and furs
• Technical Committee: CEN/TC 289 - Leather
• Drafting Committee: CEN/TC 289/WG 1 - Chemical test methods
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 15-Mar-2011
• Due Date: 19-Jan-2012
• Completion Date: 15-Mar-2011
• Ref Project: SIST EN ISO 17234-2:2011 - Leather - Chemical tests for the determination of certain azo colorants in dyed leathers - Part 2: Determination of 4-aminoazobenzene (ISO 17234-2:2011)

Overview

EN ISO 17234-2:2011 (ISO 17234-2:2011) specifies a chemical test procedure for the detection and determination of 4‑aminoazobenzene in dyed leathers. This part is supplementary to ISO 17234‑1 and is intended to reveal the use of certain azo colorants (including Solvent Yellow 1) that can release 4‑aminoazobenzene either as a free amine or after reductive cleavage. The standard is published by CEN in collaboration with IULTCS and is directly relevant to regulatory compliance under REACH (EC No. 1907/2006, Annex XVII) where 4‑aminoazobenzene is prohibited.

Key topics and technical requirements

• Scope: Special procedure to detect azo colorants that can form 4‑aminoazobenzene; complementary to ISO 17234‑1.
• Principle: Degrease and reductively cleave samples using sodium dithionite in alkaline medium at (40 ± 2) °C in a closed vessel. Released 4‑aminoazobenzene is extracted into tert‑butyl methyl ether and concentrated for analysis.
• Analytical methods: Identification/determination by HPLC with DAD (preferred for quantification), HPLC‑MS, GC‑MS, CE‑DAD; qualitative confirmation by TLC/HPTLC. Positive findings from one method must be confirmed by an alternative method.
• Sampling and sample prep: Follow ISO 2418 (sampling location) and ISO 4044 (preparation of chemical test samples).
• Reagents and standards: Use analytical‑grade reagents (NaOH, sodium dithionite, solvents), certified 4‑aminoazobenzene standard and appropriate internal standards for GC.
• Safety: 4‑aminoazobenzene is a suspected human carcinogen; strict lab safety and disposal procedures required.
• Reporting & reliability: Includes calibration, system checks and guidance on calculation with/without internal standard and method reliability.

Practical applications and users

This standard is primarily used for:

• Regulatory compliance testing (REACH / Annex XVII) for prohibited aromatic amines.
• Quality control in leather manufacturing and finishing to ensure dyes do not release hazardous amines.
• Independent testing laboratories and third‑party conformity assessment bodies performing chemical safety testing on dyed leathers and leather goods.
• Importers, brand owners and product safety managers verifying supplier compliance and preventing hazardous azo colorant use.

Keywords: EN ISO 17234-2:2011, 4‑aminoazobenzene testing, azo colorants, leather chemical tests, HPLC DAD, GC‑MS, REACH compliance.

Related standards

• ISO 17234‑1 - Determination of certain aromatic amines from azo colorants (complements Part 2)
• ISO 2418 - Sampling location for leather tests
• ISO 4044 - Preparation of chemical test samples
• REACH (EC No. 1907/2006) - Annex XVII restrictions on 4‑aminoazobenzene

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2011
8VQMH.HPLþQLSUHVNXVL]DGRORþHYDQMHGRORþHQLKD]REDUYLOQDEDUYDQHPXVQMX
GHO'RORþHYDQMHDPLQRD]REHQ]HQD,62
Leather - Chemical tests for the determination of certain azo colorants in dyed leathers -
Part 2: Determination of 4-aminoazobenzene (ISO 17234-2:2011)
Leder - Chemische Prüfungen zur Bestimmung bestimmter Azofarbstoffe in gefärbten
Ledern - Teil 2: Bestimmung von 4-Aminoazobenzol (ISO 17234-2:2011)
Cuir - Essais chimiques pour le dosage de certains colorants azoïques dans les cuirs
teints - Partie 2: Dosage du 4-aminoazobenzène (ISO 17234-2:2011)
Ta slovenski standard je istoveten z: EN ISO 17234-2:2011
ICS:
59.140.30 Usnje in krzno Leather and furs
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 17234-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2011
ICS 59.140.30
English Version
Leather - Chemical tests for the determination of certain azo
colorants in dyed leathers - Part 2: Determination of 4-
aminoazobenzene (ISO 17234-2:2011)
Cuir - Essais chimiques pour le dosage de certains Leder - Chemische Prüfungen zur Bestimmung bestimmter
colorants azoïques dans les cuirs teints - Partie 2: Dosage Azofarbstoffe in gefärbten Ledern - Teil 2: Bestimmung von
du 4-aminoazobenzène (ISO 17234-2:2011) 4-Aminoazobenzol (ISO 17234-2:2011)
This European Standard was approved by CEN on 10 March 2011.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17234-2:2011: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 17234-2:2011:2011) has been prepared by Technical Committee CEN/TC 289
“Leather”, the secretariat of which is held by UNI, in collaboration with the International Union of Leather
Technologists and Chemists Societies.
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 2011, and conflicting national standards shall be
withdrawn at the latest by September 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
INTERNATIONAL ISO
STANDARD 17234-2
IULTCS/IUC
20-2
First edition
2011-03-15
Leather — Chemical tests for the
determination of certain azo colorants in
dyed leathers —
Part 2:
Determination of 4-aminoazobenzene
Cuir — Essais chimiques pour le dosage de certains colorants azoïques
dans les cuirs teints —
Partie 2: Dosage du 4-aminoazobenzène

Reference number
ISO 17234-2:2011(E)
IULTCS/IUC 20-2:2011(E)
©
ISO 2011
ISO 17234-2:2011(E)
IULTCS/IUC 20-2:2011(E)
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ii © ISO 2011 – All rights reserved

ISO 17234-2:2011(E)
IULTCS/IUC 20-2:2011(E)
Contents Page
Foreword .iv
1 Scope.1
2 Normative references.1
3 General .1
4 Principle .2
5 Safety precautions .2
6 Apparatus.2
7 Reagents .3
8 Sampling .3
9 Procedure.4
9.1 Degreasing .4
9.2 Reductive cleavage .4
9.3 Separation and concentration of 4-aminoazobenzene.4
9.4 Calibration solution.4
9.5 Check of the analytical system .5
9.6 Chromatographic analyses .5
10 Evaluation .5
10.1 Calculation with internal standard.5
10.2 Calculation without internal standard.5
10.3 Reliability of the method.6
11 Test report.6
Annex A (informative) Chromatographic analyses .7
Annex B (informative) Reliability of the method.14
Annex C (informative) Assessment guide — Interpretation of analytical results .15
Bibliography.16

ISO 17234-2:2011(E)
IULTCS/IUC 20-2:2011(E)
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 17234-2 was prepared by the European Committee for Standardization (CEN) Technical Committee
CEN/TC 289, Leather, in collaboration with the Chemical Test Commission of the International Union of
Leather Technologists and Chemists Societies (IUC Commission, IULTCS), in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement). This method is technically
similar to the method in IUC 20-2.
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.
ISO 17234 consists of the following parts, under the general title Leather — Chemical tests for the
determination of certain azo colorants in dyed leathers:
⎯ Part 1: Determination of certain aromatic amines derived from azo colorants
⎯ Part 2: Determination of 4-aminoazobenzene

iv © ISO 2011 – All rights reserved

ISO 17234-2:2011(E)
INTERNATIONAL STANDARD
IULTCS/IUC 20-2:2011(E)
Leather — Chemical tests for the determination of certain azo
colorants in dyed leathers —
Part 2:
Determination of 4-aminoazobenzene
1 Scope
This part of ISO 17234 is supplementary to ISO 17234-1 and describes a special procedure to detect the use
of certain azo colorants in commodities, which can release 4-aminoazobenzene. The procedure also detects
4-aminoazobenzene (Solvent Yellow 1) which is already available as free amine in commodities without
reducing pretreatment.
Azo colorants that are able to form 4-aminoazobenzene generate, under the conditions of ISO 17234-1, the
amines aniline and 1,4-phenylenediamine. The presence of these 4-aminoazobenzene colorants cannot be
reliably ascertained without additional information (e.g. the chemical structure of the colorant used) or without
a special procedure.
The use of certain azo colorants, which may release, by reductive cleavage of their azo group(s), one or more
of the other aromatic amines listed in Annex XVII of Regulation (EC) No. 1907/2006 of the European
Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals
(REACH), except 4-aminoazobenzene, cannot be determined quantitatively with this method.
2 Normative references
The following referenced documents are indispensable for the application 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.
ISO 2418, Leather — Chemical, physical and mechanical and fastness tests — Sampling location
ISO 4044, Leather — Chemical tests — Preparation of chemical test samples
3 General
Certain azo colorants may release by reductive cleavage of their azo group(s), 4-aminoazobenzene, which is
proscribed under Annex XVII of Regulation (EC) No. 1907/2006 of the European Parliament and of the
Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).
Table 1 — 4-aminoazobenzene proscribed under Regulation REACH 1907/2006/Annex XVII
No. CAS number Index number EC number Substance
22 60-09-3 611-008-00-4 200-453-6 4-aminoazobenzene
ISO 17234-2:2011(E)
IULTCS/IUC 20-2:2011(E)
4 Principle
After degreasing, the leather sample is treated with sodium dithionite in an alkaline solution at 40 °C in a
closed vessel. 4-Aminoazobenzene, which is released in the process, is transferred to a tert-butyl methyl ether
phase by means of liquid/liquid extraction. An aliquot of the tert-butyl methyl ether phase is used for analysis.
The detection and determination of 4-aminoazobenzene is performed using high-performance liquid
chromatography (HPLC) with a diode array detector (DAD) or mass selective detector (HPLC/MS), capillary
gas chromatography with a mass-selective detector (GC/MS) or capillary electrophoresis with a diode array
detector (CE/DAD), or qualitatively with thin-layer chromatography (TLC, HPTLC).
If 4-aminoazobenzene is detected by one chromatographic method, confirmation shall be made using one or
more alternative methods. Amine quantification is performed by HPLC/DAD.
5 Safety precautions
5.1 The compound 4-aminoazobenzene is classified as a substance suspected to be a human carcinogen.
Any handling and disposal of this substance shall be in strict accordance with the appropriate national health
and safety regulations.
5.2 It is the user's responsibility to use safe and proper techniques when handling materials in this test
method. Consult manufacturers for specific details, such as material safety data sheets and other
recommendations.
5.3 Good laboratory practice should be followed. Wear safety glasses in all laboratory areas, and a dust
respirator and single-use gloves while handling powder colorants and 4-aminoazobenzene.
5.4 Users should comply with any national and local safety regulations.
6 Apparatus
Usual laboratory equipment and, in particular, the following.
6.1 Suitable reaction vessel, of temperature-resistant glass with a gastight closure.
6.2 Heating source, that generates a temperature of (40 ± 2) °C.
6.3 Separator, with a revolution speed of more than 3 000 r/min.
6.4 Vacuum rotary evaporator.
6.5 Pipettes, in required or variable sizes.
6.6 Ultrasonic bath, at least 160 W, with controllable heating.
−1
6.7 Horizontal shaker, with a sufficient frequency of 5 s , path length 2 cm to 5 cm.
6.8 Polypropylene or polyethylene syringe, 2 ml.
6.9 Instrumental equipment
6.9.1 Gas chromatography (GC), with mass-selective detector (MS).
6.9.2 High-performance liquid chromatography (HPLC), with gradient elution and diode array
detector (DAD) or mass-selective detector (MS).
2 © ISO 2011 – All rights reserved

ISO 17234-2:2011(E)
IULTCS/IUC 20-2:2011(E)
6.9.3 Thin-layer chromatography (TLC), or high-performance thin-layer chromatography (HPTLC)
equipment, including relevant detection.
...