EN ISO 19071:2016

Leather - Chemical tests - Determination of chromium (VI) and the reductive potential for chromium tanning agents (ISO 19071:2016)

ISO 19071:2016 specifies a test method for the determination of chromium (VI) content in chromium tanning agents. The results give information about the reductive potential of the chromium tanning agent.

Leder - Chemische Prüfungen - Bestimmung von Chrom (VI) und deren Reduktionspotential für Chrom-Gerbstoffe (ISO 19071:2016)

Diese Internationale Norm legt ein Prüfverfahren zur Bestimmung des Gehalts an Chrom(VI) in Chrom-Gerbstoffen fest. Die Ergebnisse liefern Angaben zum Reduktionspotential des Chrom-Gerbstoffes.

Cuir - Essais chimiques - Détermination de la teneur en chrome (VI) et du potentiel de réduction des agents de tannage au chrome (ISO 19071:2016)

ISO 19071:2016 spécifie une méthode d'essai permettant de déterminer la teneur en chrome (VI) dans les agents de tannage au chrome. Les résultats obtenus donnent des informations sur le potentiel de réduction de l'agent de tannage au chrome.

Usnje - Kemični preskusi - Določevanje kroma (VI) in zmanjšani potencial kromovih sredstev za strojenje (ISO 19071:2016)

Ta mednarodni standard določa preskusno metodo za določevanje vsebnosti kroma (VI) v kromovih sredstvih za strojenje. Rezultati zagotavljajo informacije o zmanjšanem potencialu kromovega sredstva za strojenje.

General Information

• Status: Published
• Publication Date: 05-Apr-2016
• Withdrawal Date: 30-Oct-2016
• 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: 06-Apr-2016
• Due Date: 27-Mar-2016
• Completion Date: 06-Apr-2016
• Ref Project: SIST EN ISO 19071:2016 - Leather - Chemical tests - Determination of Chromium (VI) and the reductive potential for chromium tanning agents (ISO 19071:2016)

Overview

EN ISO 19071:2016 / ISO 19071:2016 specifies a chemical test method for the determination of chromium (VI) content and the reductive potential of chromium tanning agents used in leather manufacture. Published by ISO and adopted by CEN, this standard provides a validated laboratory procedure for accurate chromium (VI) measurement where reducing substances in commercial tanning agents can affect recoveries.

Key topics and requirements

• Scope: Determination of Cr(VI) in chromium tanning agents; results indicate the agent’s reductive potential.
• Principle: Dissolve the tanning agent in water, react Cr(VI) with 1,5‑diphenylcarbazide to form a coloured complex, extract the complex into n‑hexanol, and measure absorbance by photometry at 540 nm.
• Standard addition procedure: Because reducing substances can lower measured Cr(VI) recovery, the method uses the standard addition technique (multiple spiked levels) to correct for reductive interference.
• Sample preparation: Homogenize product; solid samples powdered if necessary. Typical mass and dilution steps are specified for reproducible results.
• Reagents and apparatus: Analytical-grade reagents (e.g., phosphoric acid, diphenylcarbazide, potassium dichromate stock), separation funnel, horizontal shaker, spectrophotometer and 20 mm cell (or equivalent).
• Quality control: Daily recovery check with a 15 µg Cr(VI) control; calibration curve levels typically 5, 10, 20, 25, 35 µg Cr(VI). Water for analytical use in accordance with ISO 3696 is normative.
• Reporting: Results expressed as Cr(VI) content and commentary on reductive potential of the tanning agent.

Practical applications and users

• Leather tanneries and chemical suppliers use EN ISO 19071:2016 for product quality control of chromium tanning agents.
• Analytical and testing laboratories implement the method to quantify Cr(VI) for compliance testing and material characterization.
• Regulatory and compliance teams rely on the standard to support obligations under chemical regulations (e.g., REACH) by demonstrating accurate Cr(VI) measurement in the presence of reducing agents.
• R&D and formulation teams can use results to evaluate stabilisation, storage effects, and the reductive behaviour of tanning formulations.

Related standards

• ISO 3696 - Water for analytical laboratory use (referenced for reagent water quality).
• EN ISO 19071:2016 is the CEN-adopted version of ISO 19071:2016.

This standard is essential where sensitive and interference‑aware measurement of chromium (VI) in leather tanning products is required. Keywords: EN ISO 19071:2016, ISO 19071:2016, chromium (VI), chromium tanning agents, reductive potential, leather chemical tests, standard addition procedure.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2016
8VQMH.HPLþQLSUHVNXVL'RORþHYDQMHNURPD9,LQ]PDQMãDQLSRWHQFLDO
NURPRYLKVUHGVWHY]DVWURMHQMH,62
Leather - Chemical tests - Determination of Chromium (VI) and the reductive potential for
chromium tanning agents (ISO 19071:2016)
Leder - Chemische Prüfungen - Bestimmung von Chrom (VI) und deren
Reduktionspotential für Chrom-Gerbstoffe (ISO 19071:2016)
Cuir - Essais chimiques - Détermination de la teneur en chrome (VI) et du potentiel de
réduction des agents de tannage au chrome (ISO 19071:2016)
Ta slovenski standard je istoveten z: EN ISO 19071:2016
ICS:
59.140.30 Usnje in krzno Leather and furs
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 19071
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2016
EUROPÄISCHE NORM
ICS 59.140.30
English Version
Leather - Chemical tests - Determination of chromium (VI)
and the reductive potential for chromium tanning agents
(ISO 19071:2016)
Cuir - Essais chimiques - Détermination de la teneur en Leder - Chemische Prüfungen - Bestimmung von
chrome (VI) et du potentiel de réduction des agents de Chrom (VI) und deren Reduktionspotential für Chrom-
tannage au chrome (ISO 19071:2016) Gerbstoffe (ISO 19071:2016)
This European Standard was approved by CEN on 13 February 2016.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19071:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 19071:2016) has been prepared by Technical Committee 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 2016, and conflicting national standards shall
be withdrawn at the latest by October 2016.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 19071:2016 has been approved by CEN as EN ISO 19071:2016 without any modification.

INTERNATIONAL ISO
STANDARD 19071
IULTCS/IUC 35
First edition
2016-03-01
Leather — Chemical tests —
Determination of chromium (VI) and
the reductive potential for chromium
tanning agents
Cuir — Essais chimiques — Détermination de la teneur en chrome
(VI) et du potentiel de réduction des agents de tannage au chrome
Reference numbers
ISO 19071:2016(E)
IULTCS/IUC 35:2016(E)
©
ISO 2016
ISO 19071:2016(E)
IULTCS/IUC 35:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
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Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2016 – All rights reserved

ISO 19071:2016(E)
IULTCS/IUC 35:2016(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Principle . 1
4 Reagents . 1
5 Apparatus . 2
6 Sampling and sample preparation . 2
7 Determination of chromium (VI) content using the standard addition procedure.2
7.1 General . 2
7.2 Procedure . 2
8 Quality control . 3
9 Calculation and expression of the results . 3
10 Test report . 5
Bibliography . 6
ISO 19071:2016(E)
IULTCS/IUC 35:2016(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
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committee has been established has the right to be represented on that committee. International
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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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
ISO 19071 was prepared by the Chemical Testing 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, the secretariat of
which is held by UNI, in acc
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