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Background: It is often difficult to establish clinical relevance of metal exposure in cobalt-allergic patients. Dermatologists and patients may incorrectly assume that many metallic items release cobalt at levels that may cause cobalt dermatitis. Cobalt-allergic patients may be unaware that they are exposed to cobalt from handling work items, causing hand dermatitis.

SummaryThe history of chromium as an allergen goes back more than a century, and includes an interventional success with national legislation that led to significant changes in the epidemiology of chromium allergy in construction workers. The 2015 EU Leather Regulation once again put a focus on chromium allergy, emphasizing that the investigation of chromium allergy is still far from complete. Our review article on chromium focuses on the allergen's chemical properties, its potential exposure sources, and the allergen's interaction with the skin, and also provides an overview of the regulations, and analyses the epidemiological pattern between nations and across continents. We provide an update on the allergen from a dermatological point of view, and conclude that much still remains to be discovered about the allergen, and that continued surveillance of exposure sources and prevalence rates is necessary.Key words: allergic chromium dermatitis; allergy; chromium; chromium allergy; dermatitis; leather; metals; potassium dichromate; screening; spot test.Chromium is a transition metal with the atomic number 24. Industrialization and modern living have resulted in increased exposure to chromium ions for more than a century. Chromium salts can induce skin irritation and allergic contact dermatitis. These manifestations have been the basis for multiple studies, reports, and regulations (Table 1). We review chromium allergy from a dermatological perspective, providing an update combined with a historical perspective. Materials/MethodsFor the epidemiological part of this review article, a PubMed/MEDLINE literature search was performed on 10 December 2014, with the following search terms:'((((chromium or chromate or chrome or potassium dichromate) and (patch test or For a study to be included in the prevalence calculation, the prevalence rate had to be obtained from patch test clinics where the primary indication was dermatitis and not, for example, prosthesis insertion. Studies needed to report prevalence rates that would allow for calculations. Finally, we decided to only include studies published from 2004 and onwards, with the primary intention of performing an up-to-date review analysis on prevalence rates and trends during the last 10 years.The information for the remaining sections of this review article originated from a similar PubMed/ MEDLINE literature search performed with relevant search terms for the respective topics, focusing mainly on newer publications, but not neglecting older studies. The historical perspective of chromium allergy was mainly based on the doctoral theses by the Scandinavian dermatologists Bonnevie (7) . Statistical significance was predefined as a p-value of < 0.05. ResultsThe literature search resulted in a total of 1066 potential studies for the epidemiological part. Abstracts were then screened, and 132 articles were found to be relevant for further analysis. For the epidemiological comparison between Europe, North America, and Asia, a total of 31 studies were relevant. The Passivati...

Abstract-Electrochemical migration behavior of end terminals on ceramic chip resistors (CCRs) was studied using a novel experimental setup in varying sodium chloride concentrations from 0 to 1000 ppm. The chip resistor used for the investigation was 10-kΩ CCR size 0805 with end terminals made of 97Sn3Pb alloy. Anodic polarization behavior of the electrode materials was investigated using a microelectrochemical setup. Material makeup of the chip resistor was investigated using scanning electron microscopy (SEM)/energy dispersive spectroscopy and focused-ion-beam SEM. Results showed that the dissolution rate of the Sn and stability of Sn ions in the solution layer play a significant role in the formation of dendrites, which is controlled by chloride concentration and potential bias. Morphology, composition, and resistance of the dendrites were dependent on chloride concentration and potential.

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