Metal concentration analysis and dermal exposure risk modeling of heavy metal impurities in cosmetics products marketed in Seoul, Korea.

This study assesses the concentrations and evaluates the dermal exposure risk of heavy metal impurities-including lead (Pb), cadmium (Cd), arsenic (As), antimony (Sb), nickel (Ni), and mercury (Hg)-in 102 cosmetic products marketed in Seoul, Korea. Using inductively coupled plasma-mass spectrometry (ICP-MS) and a Direct Mercury Analyzer, metal concentrations were quantified and evaluated against Korean regulatory limits. Health risk modeling was performed using Margin of Safety (MoS), Hazard Quotient (HQ), Hazard Index (HI), and Lifetime Cancer Risk (LCR) models. Dermal absorption (50%) and exposure assumptions were applied based on the SCCS (Scientific Committee on Consumer Safety) Notes of Guidance (12th Revision, 2023). To ensure a conservative risk evaluation, non-detectable concentrations of Cd and Sb were substituted with LOD/2. All detected metal levels were within permissible limits. The mean concentrations for Pb, As, and Ni were 0.058 μg/g, 0.008 μg/g, and 0.095 μg/g, respectively. One-way ANOVA revealed significant differences across cosmetic types for Pb (F[4.97] = 5.679, p < 0.001) and Ni (F[4.97] = 3.642, p < 0.01). Duncan' post-hoc test further indicated that color cosmetics exhibited significantly higher concentrations of Pb and Ni compared with all other cosmetic categories. Additionally, Hg concentrations varied significantly between domestic and imported cosmetic products (p < 0.05). Although Cd and Sb were below the limit of detection (LOD) in all samples, concentrations below the LOD were conservatively substituted with LOD/2 for risk assessment calculations. All MoS values exceeded 100 (6.90 × 103 to 3.17 × 1011), and HQ and HI values were below 1, indicating negligible non-carcinogenic risk under the exposure assumptions applied in this study. LCR values for Pb, As, Ni, and Cd ranged from 2.75 × 10-11 to 5.66 × 10-6. Several values indicated negligible carcinogenic risk (<1 × 10-6), whereas the remaining values were within the USEPA acceptable risk range (1 × 10-6-1 × 10-4). While current findings suggest that these products pose negligible health risk under the exposure assumptions applied in this study, continued monitoring and stricter impurity control remain important because real-life aggregate exposure from the concurrent use of multiple cosmetic products may exceed single-product exposure estimates.