Nickel release from nickel particles in artificial sweat

Abstract

Nickel is widely used in a broad range of products, primarily made of alloys, used by humans on a daily basis. Previous assessments have shown that skin contact with some such products may cause nickel allergic contact dermatitis, induced by the release of nickel. However, data on nickel release from small nickel particles in artificial sweat for assessment of potential risks of workers in nickel-producing and nickel-using facilities are not available. The objective of this study was to fill this knowledge gap by determining nickel release from fine nickel powder ( approximately 4 microm diameter) of different loadings varying from 0.1 to 5 mg/cm(2), when immersed in artificial sweat. The amount of nickel released increased with increasing particle loading, whereas the highest release rate per surface area of particles was observed for the medium particle loading, 1 mg/cm(2), at current experimental conditions. All particle loadings showed time-dependent release rates, reaching a relative steady-state level of less than 0.1 microg/cm(2)/hr after 12 hr of immersion, whereby less than 0.5% of the nickel particle loading was released. Nickel release from particles was influenced by the surface composition, the active surface area for corrosion, particle size, and loading.

Nickel release and surface characteristics of fine powders of nickel metal and nickel oxide in media of relevance for inhalation and dermal contact

“…Nickel release studies were carried out by immersing a specific particle loading (100 mg/L: 5 mg/50 mL) in Artificial Lysosomal Fluid (ALF) of pH 4.5 at 37°C and in Artificial Sweat (ASW) of pH 6.5 at 30°C, both for exposures of 0.5, 2, 6, and 24 h. The loading of 0.1 g/L is recommended by the OECD transformation/dissolution protocol for aquatic acute tests (UN, 2009) and has previously been found to be suitable to avoid extensive particle agglomeration, compared with higher loadings (Hamel et al, 1998;Midander et al, 2006Midander et al, , 2007Turner, 2011). ALF was used to simulate intracellular inflammatory conditions in lung cells following phagocytosis (de Meringo et al, 1994), relevant to inhalation exposure.…”

“…For piercing assemblies, the nickel release limit allowed for the materials to remain in commerce is set to 0.2 lg Ni/cm 2 /week (EN, 2011). Many investigations have therefore focused on assessing the bioaccessibility of different nickel compounds, alloys, powders and/or massive material in artificial sweat (Hedberg et al, 2010b;Lidén and Carter, 2001;Lidén et al, 2008;Midander et al, 2007). Nickel-induced allergies are the most frequent reasons for contact dermatitis in the industrialized part of the world, affecting 15% of females and a few% of males (Lidén and Carter, 2001).…”

“…the bioaccessible fraction (the fraction of the sample that has been released or has been solubilized and available for uptake or absorption by humans). Due to the known relationship between the release of nickel ions and skin sensitization (Flint, 1998;Lidén and Carter, 2001;Lidén et al, 2008;Midander et al, 2007), any nickel-containing articles in direct and prolonged contact with the skin are classified as skin sensitizers when exceeding a release rate of 0.5 lg Ni/cm 2 /week, as measured by the European Standard reference test method EN 1811 (EN, 2011;EC, 2009). For piercing assemblies, the nickel release limit allowed for the materials to remain in commerce is set to 0.2 lg Ni/cm 2 /week (EN, 2011).…”

The detection and measurement of interleukin-6 in venous and capillary blood samples, and in sweat collected at rest and during exercise

“…Artificial sweat was prepared according to the standard reported previously (Midander et al 2007). Eight-point standard curves were set up for TBS/FCS and artificial sweat, while a three-point series spike with 10 pg.ml -1 rhIL-6 was prepared in real sweat.…”

Real-time colorimetric hydration sensor for sport activities

“…NaCl solutions in concentrations of 40, 26.5 and 47.9 mM were use as indicators of normal physiological condition, over-hydration and dehydration. The final optimized formulation was applied to artificial sweat of pH 6.7 according to EN1811 standard [22].…”