In 1991, Denmark banned the sale of nickel-releasing objects that contact the skin for prolonged times and which release approximately >0.5 micrograms/cm2/week as measured by a dimethylglyoxime (DMG) test.(15)
|Pink positive DMG test for nickel release from jeans’ button.
The amended Nickel Directive has now been subsumed into the REACH regulation (EC) Annex XVII.(16) This says that nickel:
1. "Shall not be used:
a. in all post assemblies which are inserted into pierced ears and other pierced parts of the human body unless the rate of nickel release from such post assemblies is less than 0.2µg/cm2/week (migration limit);
b. in articles intended to come into direct and prolonged contact with the skin such as:
- necklaces, bracelets and chains, anklets, finger rings,
- wrist-watch cases, watch straps and tighteners
- rivet buttons, tightener, rivets, zippers and metal marks, when these are used in garments, if the rate of nickel release from the parts of these articles coming into direct and prolonged contact with the skin is greater than 0.5µg/cm2/week; and
c. in articles such as those listed in point (b) where these have a non-nickel coating unless such coating is sufficient to ensure that the rate of nickel release from those parts of such articles coming into direct and prolonged contact with the skin will not exceed 0.5µg/cm2/week for a period of at least two years of normal use of the article.
2. Articles which are the subject of paragraph 1 shall not be placed on the market unless they conform to the requirements set out in those points."
It should be noted that the 0.5 micrograms nickel/cm2/week is as determined in the nickel release standard EN 1811 and it is understood that the release rates would not protect 100% of sensitized people from elicitation of ACD. However, clinical data indicates that the vast majority of sensitized individuals would not experience nickel ACD at this level of nickel release and individuals who were not previously sensitized would require substantially higher concentrations than 0.5 micrograms nickel/cm2/week to be released to the skin for nickel sensitization to occur.(17)
EN 1811:1998(18) (“Reference Test Method for Release of Nickel from Products Intended to Come into Direct and Pro-longed Contact with the Skin”) originally came into force in 1998 and its use to test articles for nickel release was successful in removing from the market many unsuitable articles that could have caused nickel dermatitis. However, the test was not sufficiently reliable and reproducible. With CEN (Comité Européen de Normalisation, European Committee for Standardization) Mandate M414, a standardization working group (CEN TC 347 WG 1) was set up in 2007 with the objective of improving the test procedure. A modified procedure incorporating a corrigendum in May 2012 (EN 1811:2011)(19) was approved, followed by an amendment in 2015 with the publication of the current EN 1811:2011+A1:2015. This amendment simplified the decision categories and provided a pass level of effectively 0.88 and 0.35 µg Ni/cm2/week for articles and piercings, respectively, to account for the combined measurement of uncertainty.
In parallel, following a mandate by the European Commission (M448), CEN TC 170 WG8 has developed a new standard on nickel release testing from spectacle frames and sunglasses, EN 16128:2015 (“Ophthalmic optics. Reference method for the testing of spectacle frames and sunglasses for nickel release”).
Also in used, though not approved for compliance testing, is the CR 12471:2002 standard, a “formalized” version of the DMG (dimethylglyoxime) test. It is a screening method to test for nickel release from alloys and coatings in items that come into direct and prolonged contact with the skin (a relatively easy, quick, and cheap method compared with EN 1811).
For coated products there is a requirement that the article should not release nickel above the specified limits after two years of normal use and this was covered by EN 12472:1998 (Method for the Simulation of Wear and Corrosion for the Detection of Nickel Release from Coated Item). This period of use was simulated by tumbling the articles in a mixture of abrasive paste and ceramic particles. However, this was judged too aggressive and, therefore, after considerable investigation, wood and nutshells replaced the ceramic particles and the method of tumbling was specified in more detail. This resulted in the re-issue of the standard as EN 12472:2005 and, after a corrigendum in 2009, as EN 12472:2005+A1:2009.
A very small part of the population is hypersensitive to nickel. These individuals react to lower concentrations of nickel on the skin than most nickel-sensitive individuals and potentially by oral exposure. Prevention of elicitation in these individuals is important and is done on a case-by-case basis. Regulation and prevention of nickel sensitization and nickel ACD of the general population is not intended to protect hypersensitive individuals.
15. Kanerva, L.; Sipiläinen-Malm, T.; Estlander, T.; Zitting, A.; Jolanki, R.; Tarvainen, K. 1994. Contact Dermatitis 31(5): 299-303.
16. European Commission. 2007. REACH Annex XVII, Restrictions on the manufacture, placing on the market and use of certain dangerous substances, preparations and articles. Official Journal of the European Union. 29.5.2007. L 136/139-40.http://www.reach-compliance.eu/english/REACH-ME/engine/sources/reach-annexes/launch-annex17.html (last accessed June 2016)
17. Gawkrodger, D.J. 1996. Nickel dermatitis: how much nickel is safe? Contact Dermatitis 35: 267-271.
18. European Committee for Standardization (CEN). 1998. EN 1811. Reference Test Method for Release of Nickel from Products Intended to Come into Direct and Prolonged Contact with the Skin. Brussels, CEN.
19. European Committee for Standardization (CEN). 2011. EN 1811:2011. 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. CEN/TC 347 - Methods for analysis of allergens. Brussels, CEN.