Chromium and Cobalt in Used Leather Items: A Danish Market Survey.

INTRODUCTION: Leather is a recognised source of contact allergy to chromium (Cr). Cobalt (Co) has also been identified as a potential leather-related allergen. OBJECTIVES: To assess the presence and release of Cr and Co in used leather items available on the Danish secondhand market. METHODS: Thirty-four used consumer leather items with expected direct skin contact during normal use were purchased from secondhand shops in Greater Copenhagen, Denmark. Cr and Co were measured using handheld X-ray fluorescence (XRF). Cr(VI) was measured according to International Organization for Standardization (ISO) standard 17 075-1 following pre-conditioning with ISO 10195. Extractable Co was analysed using ISO 17072-1 and inductively coupled plasma mass spectrometry. RESULTS: Cr(VI) was detected in 12/34 (35.3%) items, with an average concentration of 1.77 mg/kg (range: 0.52-4.16). Co was detected in 7/34 (20.6%) items, with an average concentration of 0.63 mg/kg (range: 0.33-1.44). Shoes accounted for most items with higher Cr(VI) concentrations. CONCLUSION: Used leather items may contain measurable levels of Cr(VI) and Co. Secondhand leather represents a relevant exposure scenario that should be considered in future exposure assessments and regulatory discussions.