Percutaneous Penetration and Dermal Exposure Risk Assessment of UV Absorbents in Sunscreens and Isolation Cosmetics

Abstract

Ultraviolet absorbents (UVs) make up a group of industrial chemicals that is used in various consumer products and industrial applications. Due to their extensive production and usage, UVs have been detected in multiple environmental matrixes. Recently, UVs have garnered significant attention because of their probable adverse impacts on human health and the environment. This study examines UVs levels in sunscreens and isolation cosmetics and further assesses human exposure to UVs through the application of cosmetics. The total concentrations of nine UVs in 87 sunscreen and isolation cosmetic products ranged from 75.5 to 4.25 × 104 ng/g. Among them, 2-(2-hydroxy-5-methyl-phenyl)benzotriazole (UV-P) and 2-hydroxy-4-(octoxy)benzophenone (UV-531) had the highest concentrations. Use of the EpiSkin model indicated rapid absorption and strong dermal penetration by UV-328 following 36 h of exposure with a cumulative absorption rate of 41.8% ± 2.82%. Other congeners are expected to be distributed in the dermal tissue and donor fluid. Furthermore, this study explored potential mechanisms implicating skin biochemical barriers in the metabolism and transport of UVs. The potential of UVs to act as substrates and inhibitors of P450 enzymes was assessed, and their metabolites were predicted. Molecular docking simulations demonstrated that UVs can significantly interact and bind with three transport proteins in skin: MDR1, OATP2B1, and OATP3A1. Daily UVs exposure through the skin was assessed, revealing that dermal absorption levels of UV-P in sunscreen sprays (4.66 × 103 ng/(kg bw day)) and sunscreens (6.01 × 103 ng/(kg bw day)) were close to or exceeded the reference dose (RfD) and therefore require more attention.