CEN/TR 12471:2022

SLOVENSKI STANDARD
01-september-2022
Nadomešča:
SIST CR 12471:2004
Presejalna metoda za prisotnost niklja v izdelkih, vstavljenih v prebodene dele
človeškega telesa, in izdelkih, namenjenih neposrednemu in daljšemu stiku s kožo
Screening test for the presence of nickel in articles which are inserted into pierced parts
of the human body and articles intended to come into direct and prolonged contact with
the skin
Screeningverfahren für die Nickelabgabe aus Erzeugnissen, die in durchstochene
Körperteile eingeführt werden, und Erzeugnissen, die unmittelbar und länger mit der
Haut in Berührung kommen
Méthode de tri pour la libération du nickel sur les articles qui sont introduites dans les
parties percées du corps humain et les produits destinée à entrer en contact direct et
prolongé avec la peau
Ta slovenski standard je istoveten z: CEN/TR 12471:2022
ICS:
39.060 Nakit Jewellery
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TR 12471
TECHNICAL REPORT
RAPPORT TECHNIQUE
February 2022
TECHNISCHER BERICHT
ICS 39.060 Supersedes CR 12471:2002
English Version
Screening test for the presence of nickel in articles which
are inserted into pierced parts of the human body and
articles intended to come into direct and prolonged
contact with the skin
Méthode de tri pour la présence de nickel dans les Screeningverfahren für die Nickelabgabe aus
articles introduits dans les parties percées du corps Erzeugnissen, die in durchstochene Körperteile
humain et les produits destinés à entrer en contact eingeführt werden, und Erzeugnissen, die unmittelbar
direct et prolongé avec la peau und länger mit der Haut in Berührung kommen

This Technical Report was approved by CEN on 24 January 2022. It has been drawn up by the Technical Committee CEN/TC 347.

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United Kingdom.
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COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

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© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 12471:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Reagents . 5
6 Apparatus . 6
7 Procedure . 7
7.1 Preparation of solutions . 7
7.1.1 Dimethylglyoxime test solution . 7
7.1.2 Artificial sweat solution . 7
7.1.3 Dithiooxamide test solution . 7
7.1.4 Sodium acetate buffer solution . 8
7.1.5 Degreasing solution . 8
7.2 Sample preparation — Cleaning of the surfaces to be tested . 8
7.3 Test procedure . 8
7.4 Testing of interlayers or substrates under outer coatings — Abrasion of surfaces . 10
8 Interpretation of results . 10
9 Test report . 11
Bibliography . 12
European foreword
This document (CEN/TR 12471:2022) has been prepared by Technical Committee CEN/TC 347
“Methods for analysis of allergens”, the secretariat of which is held by SNV.
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.
This document supersedes CR 12471:2002.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
Introduction
This document provides a completely revised and restructured edition of CR 12471:2002, Screening
tests for nickel release from alloys and coatings in items that come into direct and prolonged contact with
the skin.
This document has been prepared for the detection of nickel release. The described method is cost-
effective. It has particular relevance in relation to nickel contact dermatitis. In order to decrease the
incidence of nickel contact dermatitis, the European Commission introduced in 1994 the Nickel
Directive (94/27/EC), which specified a limit value for nickel content in articles inserted into pierced
parts of the human body and a limit value for nickel release from articles intended to come into direct
and prolonged contact with the skin.
The Nickel Directive has been replaced by REACH regulation (EC) No 1907/2006 in 2006. According to
REACH regulation Annex XVII, entry no 27, the nickel release for articles inserted into pierced parts of
the human body, has to be less than 0,2 µg/cm /week, whereas for articles intended to come into direct
and prolonged contact with the skin, it is 0,5 µg/cm /week or less.
European Standard EN 1811, Reference test method for release of nickel from all post assemblies which
are inserted into pierced parts of the human body and articles intended to come into direct and prolonged
contact with the skin, is used to determine whether such articles are in compliance with the
Regulation (EC) No 1907/2006 of the European Parliament and of the Council (REACH), Annex XVII,
entry no 27, as amended.
1 Scope
This document provides a screening test based upon the use of dimethylglyoxime for detecting the
presence of nickel in articles that are inserted into pierced parts of the human body and those that are
intended to come into direct and prolonged contact with the skin.
This screening test is suitable for manufacturers and importers as a qualitative method for detecting the
presence of nickel in articles.
NOTE The reference method for the measurement of nickel release is EN 1811, or for spectacle frames and
sunglasses, EN 16128.
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 ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696)
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological 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 method is based on the formation of a red coloured metal complex when nickel ions react with a
solution of dimethylglyoxime in the presence of ammonia.
In order to increase the sensitivity of the screening test, pre-treatment with artificial sweat and heat is
used to induce corrosion of the surface, simulating the influence of sweat when the article is in contact
with the skin. This screening method provides a result in a short time.
5 Reagents
All reagents should be of pro analysis grade or better.
5.1 Deionized water, according to EN ISO 3696, grade 2.
5.2 Ammonia solution, 10 % ammonia.
This solution may be prepared from a more concentrated ammonia solution, for example, one with a
mass fraction of 24 % or 30 % NH .
5.3 Sodium chloride, NaCl.
5.4 DL-Lactic acid, CH CHOHCOOH, > 88 % (m/m).
5.5 Urea, CO(NH ) .
2 2
5.6 Dimethylglyoxime, C H N O , 99 % or test strips (6.8) containing dimethylglyoxime.
4 8 2 2
5.7 Ethanol, C H OH, > 95 % (V/V).
2 5
5.8 Sodium hydroxide, pellets, purity ≥ 98 %, anhydrous.
5.8.1 Preparation of 1 M sodium hydroxide solution:
Weigh 4 g ± 0,01 g sodium hydroxide (5.8), transfer to a 100 ml beaker and add 50 ml deionized
water (5.1). Stir and cool to room temperature. Transfer the solution to a 100 ml volumetric flask and
make up to volume with deionized water (5.1).
Alternatively, it is possible to use 1 M ready-to-use solution.
5.8.2 Preparation of 0,1 M sodium hydroxide solution:
Transfer 25 ml of the 1 M sodium hydroxide solution (5.8.1) to a 250 ml volumetric flask and make up
to volume with deionized water (5.1).
Alternatively, it is possible to use 0,1 M ready-to-use solution.
5.9 Hydrochloric acid, 32 % (m/m).
5.9.1 Preparation of 0,1 M hydrochloric acid:
Transfer 1 ml hydrochloric acid (5.9) to a 100 ml volumetric flask and make up to volume with
deionized water (5.1).
Alternatively, it is possible to use 0,1 M ready-to-use solution.
5.10 Sodium dodecyl sulfate or sodium alkyllauryl sulfate or another surface-active anionic
detergent.
Additionally, the following reagents are required for the test with dithiooxamide (7.3.8):
5.11 Dithiooxamide, C H N S .
2 4 2 2
5.12 Sodium acetate trihydrate, C H NaO ·3H O.
2 3 2 2
5.13 Acetic acid, glacial acetic acid, C H O .
2 4 2
6 Apparatus
6.1 Appropriate laboratory apparatus.
6.2 Flat-bottomed dish, made of glass or another non-metallic material. Not required for the pre-
test.
6.3 Graduated pipette, volume 50 µl.
6.4 Cotton-wool-tipped sticks (white cotton wool on a white stick).
6.5 pH-meter.
6.6 Laboratory oven, adjustable to a temperature of 50 °C ± 3 °C. Required for the laboratory test
(7.3.5).
6.7 Abrasive paper, between grade 600 and 1200 inclusive.
6.8 Dimethylglyoxime test strips for detection of nickel ions (optional).
6.9 Balance, with an accuracy of 0,01 g.
7 Procedure
7.1 Preparation of solutions
7.1.1 Dimethylglyoxime test solution
The 0,8 % dimethylglyoxime alcoholic solution is prepared as follows:
Weigh 0,8 g ± 0,05 g of dimethylglyoxime (5.6) into a 100 ml volumetric flask, dissolve in ethanol (5.7)
and make up to volume.
7.1.2 Artificial sweat solution
Fresh artificial sweat solution shall be prepared every day that testing is being performed.
The artificial sweat solution consists of deionized water (5.1) and the following:
— 0,5 % (m/m) sodium chloride (5.3);
— 0,1 % (m/m) lactic acid (5.4);
— 0,1 % (m/m) urea (5.5); and
— 1 M (5.8.1) and 0,1 M (5.8.2) sodium hydroxide solution.
The artificial sweat solution is prepared as follows:
Fill a 1 000 ml beaker with 900 ml deionized water (5.1). Add 1 g ± 0,01 g urea (5.5), 5 g ± 0,05 g
sodium chloride (5.3) and 1 g ± 0,01 g lactic acid (5.4) and stir until all added reagents are dissolved.
Calibrate a pH meter using suitable calibration solutions according to the manufacturer’s instructions.
Immerse the pH electrode into the artificial sweat solution and determine the pH. Slowly and carefully
add 1 M sodium hydroxide (5.8.1) drop by drop until a pH of 5,5 is reached; subsequently, slowly and
carefully add 0,1 M sodium hydroxide (5.8.2) with constant stirring until a stable pH of (6,5 ± 0,05) is
reached.
Measure the pH 10 min after the last addition of 0,1 M sodium hydroxide (5.8.2) in order to ensure that
the pH is still in the range of (6,5 ± 0,05).
Transfer the solution to a 1 000 ml volumetric flask and make up to volume with deionized water. Prior
to use, make sure that the pH of the artificial sweat solution is in the range of (6,5 ± 0,05).
If it is necessary to reduce the pH of the solution to (6,5 ± 0,05) prior to the test, carefully add
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