Determination of potentially toxic elements in selected facial cosmetics sold in Kano metropolis and their health risk assessment

The increasing consumption of facial cosmetics has raised concerns regarding contamination by potentially toxic elements (PTEs) and associated health risks. This study investigated the concentrations of cadmium (Cd), cobalt (Co), chromium (Cr), nickel (Ni), and lead (Pb) in selected brands of facial cosmetics—foundation, lip gloss, face serum, eyeliner, and mascara sold in Kano metropolis, Nigeria, and evaluated the potential non‑carcinogenic and carcinogenic risks to consumers. Cosmetic samples were digested using a mixed‑acid system (HNO₃–H₂SO₄–HClO₄; 1:1:1) and analyzed by atomic absorption spectrometry. The PerkinElmer PinnAcle 900H AAS with precision in the range of 0.5–5% provided reliable, sensitive, and precise determination of trace-level metals, making it suitable for the quantification of potentially toxic elements in cosmetic matrices. Health risk assessment was performed using systemic exposure dosage (SED), margin of safety (MoS), hazard quotient (HQ), hazard index (HI), and lifetime cancer risk (LCR) models. Mean metal concentrations (mg/kg) varied across products, with notably elevated Pb in eyeliners and relatively higher Cr in lip glosses and eyeliners. MoS values were generally above the acceptable threshold (> 100), indicating safety, except for facial foundation and face serum where certain metals presented MoS < 100. HQ and HI values were < 1 for most products, suggesting minimal non‑carcinogenic risk, while face serum showed HQ/HI ≥ 1. LCR values were within acceptable limits (10−6–10−4) for mascara, eyeliner, and lip gloss but exceeded 10⁻4 for facial foundation and face serum. These findings highlight the need for stricter regulatory surveillance of cosmetic products in Nigeria, particularly foundations and facial serums.