Gold and Nickel Release From Gold-Plated Earrings Under Cysteine-Modified Artificial Sweat Conditions.

BACKGROUND

Contact allergy to gold is frequently observed in patch testing, although with low clinical relevance. Nickel allergy, in contrast, is common, clinically relevant, and nickel release from jewellery remains a regulatory concern. Standardised artificial sweat tests show no detectable gold release from gold-containing jewellery.

OBJECTIVES

To assess surface composition and the release of nickel and gold from gold-plated earrings under clinically relevant biochemical conditions.

METHODS

Ten pairs of low-cost gold-plated earrings were analysed by scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS) and X-ray fluorescence. Metal release was assessed using a cysteine-modified artificial sweat solution at 30°C for 168 h. Gold and nickel concentrations were quantified by inductively coupled plasma mass spectrometry.

RESULTS

Nickel release was detected in 10/10 earrings (median: 2.1 μg/cm2, range: 0.00032-10.0) frequently exceeding the EU regulatory limit. Gold release was detected in 4/10 earrings (median: 0.00092 μg/cm2, range: 0.00041-0.21). Gold was identified by cross-sectional SEM/EDS in a subset of components (6/20) but was not detected by top-down XRF analysis.

CONCLUSION

Nickel release from gold-plated earrings was widespread and often exceeded regulatory limits, indicating that gold plating does not reliably prevent nickel exposure. Gold release occurred in some earrings, but the clinical relevance remains uncertain.