Analysis for the potential of polystyrene and TiO2 nanoparticles to induce skin irritation, phototoxicity, and sensitization

► Polystyrene and TiO2 nanoparticles (NPs) induce no phototoxicity, acute cutaneous irritation, or skin sensitization. ► Polystyrene and TiO2 NPs were not dermal sensitizers. ► Results from human skin equivalent models (HSEMs) correspond well with those from animal models. ► HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.