Bioaccessibility of nickel and cobalt in powders and massive forms of stainless steel, nickel- or cobalt-based alloys, and nickel and cobalt metals in artificial sweat.

Nickel (Ni) and cobalt (Co) are the most common metal allergens upon skin contact at occupational settings and during consumer handling of metals and alloys. A standardized test (EN, 1811) exists to assess Ni release from articles of metals and alloys in massive forms intended for direct and prolonged skin contact, but no corresponding test exists for other materials such as powders or massive forms of alloys placed on the market or to determine the release of Co, for which only limited data is available. Differences in Ni and Co release from massive forms of a range of common stainless steels and some high-alloyed grades compared to Ni and Co metals were therefore assessed in artificial sweat for 1 week at 30 °C according to EN 1811.

Mechanistic insight on the combined effect of albumin and hydrogen peroxide on surface oxide composition and extent of metal release from Ti6Al4V.

The titanium-aluminium (6 wt%)-vanadium (4 wt%) (Ti6Al4V) alloy is widely used as an orthopedic and dental implant material due to its high corrosion resistance in such environments. The corrosion resistance is usually determined by means of electrochemical methods, which may not be able to detect other chemical surface reactions. Literature findings report a synergistic effect of the combination of the abundant protein albumin and hydrogen peroxide (H O ) on the extent of metal release and corrosion of Ti6Al4V.

Surface passivity largely governs the bioaccessibility of nickel-based powder particles at human exposure conditions.

The European chemical framework REACH requires that hazards and risks posed by chemicals, including alloys and metals, are identified and proven safe for humans and the environment. Therefore, differences in bioaccessibility in terms of released metals in synthetic biological fluids (different pH (1.5-7.

Surface-rain interactions: differences in copper runoff for copper sheet of different inclination, orientation, and atmospheric exposure conditions.

Predictions of the diffuse dispersion of metals from outdoor constructions such as roofs and facades are necessary for environmental risk assessment and management. An existing predictive model has been compared with measured data of copper runoff from copper sheets exposed at four different inclinations facing four orientations at two different urban sites (Stockholm, Sweden, and Milan, Italy) during a 4-year period. Its applicability has also been investigated for copper sheet exposed at two marine sites(Cadiz, Spain, for 5 years, and Brest, France, for 9 years).

Adsorption of lysozyme on silver and its influence on silver release.

Silver is increasingly used in antimicrobial coatings of biomedical devices and implants to hinder infections. As proteins have been shown to largely influence the extent of released metals from various metal surfaces at biological conditions, silver may also be influenced in the same way. The aim of this study is to relate the structure of adsorbed lysozyme (LSZ) to the release of silver from metallic silver surfaces.

Release of Si from silicon, a ferrosilicon (FeSi) alloy and a synthetic silicate mineral in simulated biological media.

Unique quantitative bioaccessibility data has been generated, and the influence of surface/material and test media characteristics on the elemental release process were assessed for silicon containing materials in specific synthetic body fluids at certain time periods at a fixed loading. The metal release test protocol, elaborated by the KTH team, has previously been used for classification, ranking, and screening of different alloys and metals. Time resolved elemental release of Si, Fe and Al from particles, sized less than 50 µm, of two grades of metallurgical silicon (high purity silicon, SiHG, low purity silicon, SiLG), an alloy (ferrosilicon, FeSi) and a mineral (aluminium silicate, AlSi) has been investigated in synthetic body fluids of varying pH, composition and complexation capacity, simple models of for example dermal contact and digestion scenarios.

Inter-laboratory validation of bioaccessibility testing for metals.

Bioelution assays are fast, simple alternatives to in vivo testing. In this study, the intra- and inter-laboratory variability in bioaccessibility data generated by bioelution tests were evaluated in synthetic fluids relevant to oral, inhalation, and dermal exposure. Using one defined protocol, five laboratories measured metal release from cobalt oxide, cobalt powder, copper concentrate, Inconel alloy, leaded brass alloy, and nickel sulfate hexahydrate.

Critical review: Copper runoff from outdoor copper surfaces at atmospheric conditions.

This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chlorides, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate.

Corrosion and runoff rates of Cu and three Cu-alloys in marine environments with increasing chloride deposition rate.

Bare copper sheet and three commercial Cu-based alloys, Cu15Zn, Cu4Sn and Cu5Al5Zn, have been exposed to four test sites in Brest, France, with strongly varying chloride deposition rates. The corrosion rates of all four materials decrease continuously with distance from the coast, i.e.

New UK nickel-plated steel coins constitute an increased allergy and eczema risk.

Background: Nickel-plated steel coins have recently been introduced in the United Kingdom.

Objectives: To compare the performance and allergy risk of the new nickel-plated coins (five and ten pence) with those of the cupro-nickel coins being replaced.

Materials And Methods: Coin handling studies with assessment of skin exposure and metal release in artificial sweat were performed.

Risks of using membrane filtration for trace metal analysis and assessing the dissolved metal fraction of aqueous media--a study on zinc, copper and nickel.

Membrane filtration is commonly performed for solid-liquid separation of aqueous solutions prior to trace metal analysis and when assessing "dissolved" metal fractions. Potential artifacts induced by filtration such as contamination and/or adsorption of metals within the membrane have been investigated for different membrane materials, metals, applied pressures and pre-cleaning steps. Measurements have been conducted on aqueous solutions including well-defined metal standards, ultrapure water, and on runoff water from corroded samples.

Corrosion-induced release of the main alloying constituents of manganese-chromium stainless steels in different media.

The main focus of this paper is the assessment of release rates of chromium, nickel, iron and manganese from manganese-chromium stainless steel grades of low nickel content. The manganese content varied between 9.7 and 1.

Corrosion-induced release of Cu and Zn into rainwater from brass, bronze and their pure metals. A 2-year field study.

A 2-year field study has been conducted in an urban environment to provide annual release rates of copper and zinc from brass (20 wt% Zn) and copper and tin from bronze (6 wt% Sn) compared to sheets of their pure alloy constituents, copper and zinc. Despite relatively low nominal bulk alloy content, substantially more zinc was released from brass compared to copper. Both metals were released at a significantly slower rate from the brass alloy, compared to the pure metals.