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http://news.excite.ca/news/r/011126/09/odd-eurocoins-dc Nov. 26, 2001

Euro Coins Could Cause Skin Disease - Mon, Nov 26 9:21 AM EST STOCKHOLM (Reuters) - Two of the eight euro coins due to come into circulation in January release so much nickel that people allergic to the metal could develop hand eczema, according to a study obtained by Reuters on Friday…

…study by a Swedish dermatologist and British laboratory scientist said. Earlier studies which tested French, British and Swedish coins containing nickel were also found to have the potential to cause nickel allergies, it said…

…Fifteen percent of all women and two to five percent of men in the industrialized world are prone to nickel allergy.

…The study, published earlier this year in the journal Contact Dermatitis, was written by dermatologist Carola Liden at Sweden's Karolinska Institute and Stephen Carter of Britain's Laboratory of the Government Chemist in Middlesex. The one- and two-euro coins have a potential nickel release up to 100 times greater than the EU directive's upper limit, the study found.


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31994L0027European Parliament and Council Directive 94/27/EC of 30 June 1994 amending for the 12th time Directive 76/769/EEC on the approximation of the laws, regulations and administrative provisions of the Member States relating to restrictions on the marketing and use of certain dangerous substances and preparationsOfficial Journal L 188 , 22/07/1994 P. 0001 - 0002

ANNEX '28. Nickel CAS No 7440-0-20 EINECS No 2311114 and its compoundsMay not be used: ..2. in products intended to come into direct and prolonged contact with the skin such as:- earrings,- necklaces, bracelets and chains, anklets, finger rings,- wrist-watch cases, watch straps and tighteners,- rivet buttons, tighteners, rivets, zippers and metal marks, when these are used in garments

if the rate of nickel release from the parts of these products coming into direct and prolonged contact with the skin is greater than

0,5 μg/cm²/week


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Risques allergiques des euros: des scientifiques français contestent les tests

PARIS, 12 sept (AFP) - Des scientifiques français ont mis en cause jeudi une étude suisse publiée dans la revue Nature, selon laquelle les pièces de 1 et 2 euros présenteraient des risques pour les personnes allergiques au nickel.

Dans un communiqué à l'AFP, Thomas Govers et Paul-Guy Fournier, du CNRS, co-auteurs d'un article sur "la contamination par le nickel et d'autres métaux lors de la manipulation des pièces de monnaie", assurent que "les tests utilisés par les chercheurs de Zurich ne sont pas appropriés pour évaluer le risque allergique dû au nickel".

"En effet, selon le communiqué, ces tests sont des tests de solubilisation sur des périodes longues alors que la manipulation courante d'une pièce de monnaie ne dure que quelques secondes. Dans ce cas, le transfert de contamination métallique est surtout dû au frottement et non pas à un phénomène de dissolution".

Selon les chercheurs français, dont l'étude a été publiée ce mois-ci aux Comptes Rendus de l'Académie des Sciences où elle a été présentée par le prix Nobel de physique Pierre-Gilles de Gennes, "des tests qui simulent de manière réaliste la manipulation journalière montrent que les pièces de 1 et 2 euros transfèrent environ deux fois moins de nickel que les anciennes pièces françaises en nickel".


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June 2002

Phys. Chem. News 6 (2002) 82-92

CONTAMINATION PROVOQUEE PAR DES MONNAIES EN EUROS ET EN FRANCS FRANÇAIS DUE A LA LIXIVIATION ET AU FROTTEMENT

P.-G. Fournier, T. Govers, M. Abani, H. Boughaleb, M. Monkade


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C. R. Physique 3 (2002) 749–758

Contamination par le nickel et d’autres métaux lors de la manipulation des pièces de monnaie – comparaison entre francs français et euros

P.-G. Fournier , T.R. Govers , J. Fournier , M. Abani

Reçu le 1er mars 2002 ; accepté le 26 juin 2002

Note présentée par Pierre-Gilles de Gennes.


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Solvation experiments are not appropriate to evaluate metal

contamination resulting from the handling of coins

Manipulation tests offer a reliable means to evaluate such

metal contamination


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Polishing test is a reliable method to evaluate « reservoir »

accessible to metal transfer during the handling of coins

Potential nickel contamination from a used 2€ is lower than that from a used 2F by a factor 2.4

… but by only a factor 2.4 rather than by a factor 7


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« Baskets » of 10 of each of 8 different denominations

Ratios of euros to French francs

Only 2 of the 8 euro coins contain nickel !


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Both in manipulation tests and in patch tests, the 1- and

2€ coins behave like any other copper-nickel piece


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Ongoing


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"Monolayer" ≈ 1015 atoms/cm2 ; MW Ni = 58.7

Accessible nickel on 2€ ≈ 5μg on 2*2.67 cm2

= (0.9E-6 g/cm2 * 6E23 atoms / 58.7g) / 1015 atoms/cm2

≈ 9 monolayers

Nickel contamination from single manipulation of 2€ ≈ 0.25 μg on 2*2.67 cm2

≈ 0.5 monolayer


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"Monolayer" ≈ 1015 atoms/cm2 ; MW Ni = 58.7

Accessible nickel on 2€ ≈ 5μg on 2*2.67 cm2

= (0.9E-6 g/cm2 * 6E23 atoms / 58.7g) / 1015 atoms/cm2

≈ 9 monolayers

Nickel contamination from single manipulation of 2€ ≈ 0.25 μg on 2*2.67 cm2

≈ 0.5 monolayer

Or :

Density of nickel and of copper ≈ 9 g/cm3

Spherical particle of 10 μm radius ≈ 3.8 E-8 g of which ≈ E-8 g nickel if 25%

Accessible nickel on 2€ ≈ 5μg ≈ 500 particles of 10 μm

Nickel contamination from single manipulation of 2€ ≈ 0.25 μg

≈ 25 particles of 10 μm


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de Jesus et al. Surf. Sci. 1996

Sputtering of polished 1€

Oxidation of Ni foil 5E-6 Torr O2


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de Jesus et al. Surf. Sci. 1996

From comparison with oxidation experiments by de Jesus

et al. conclude that copper-nickel surface is covered by

about 2 nm oxide layer ( 10 monolayers)


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10 seconds sputtering measurably increases Ni°

contribution

Polishing the coin (equivalent to about 20 manipulations)

does not

Considering that 10 sec. sputtering removes about

1 monolayer or less, conclude that 1 manipulation

removes significantly less than 1/20 of a monolayer

Measured contamination corresponds to about 0.5

monolayers

Particulates must make up major part of transferred

contamination


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  • Also in favour of particles hypothesis:

  • Contamination new coins ≈ composition of coin

  • Copper on used pure-nickel coins

  • « Playing » test  contamination enhanced

  • and ≈ composition coins

  • - Handling cleans coins

  • Contamination upon air exposure builds up slowly, if at all

  • in usage, rapid build-up of contamination


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  • If particles make up major part of contamination,

  • two aspects to allergic risk,

  • which is due to dissolved ions:

  • How much contamination is transferred ? This we know.


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  • If particles make up major part of contamination, two aspects

  • to allergic risk, which is due to dissolved ions:

  • How much contamination is transferred ? This we know.

  • How fast do particles dissolve ?


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How fast do particles dissolve ?


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The density d of nickel and of copper-nickel alloys is about 9 g/cm3. Equating ρ to the sums of the metal release rates obtained in our patch tests, one finds:

ρ ≈ 30 μg/cm2/week for pure nickel

ρ ≈ 85 μg/cm2/week for copper-nickel alloy

If R0 is of the order of 1 μm 

t1/2≈ 6 weeks for pure nickel

t1/2 ≈ 2 weeks for copper-nickel alloy

!!


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  • TENTATIVE conclusion, depending on particle properties:

  •  Particles will remain on the fingers until person washes hands

  •  Relative risk of nickel allergy ≈ amount of nickel transferred

  • times relative rate of solubilisation

  • 1- and 2€ compared to other copper-nickel coins :

  • Transfer twice as low, similar solubilisation  50% lower risk

  • 1- and 2€ compared to pure-nickel coins :

  • transfer twice as low, solubilisation three times faster

  • 50% higher risk

  • Introduction of euro has reduced allergic risk mainly because

    6 out of 8 coins do not contain nickel


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Druska & Strehblow , Corrosion Sci. 1996


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TENTATIVE

recommendation:

IF Ni maintained

Replace

Cu75Ni25

by

Ni100

Replace

Cu75Zn20Ni5

by

Cu92Al6Ni2

Thanks for your interest !


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