The growing utilization of nanomaterials (NMs) in nanotechnology products lead to a potential increase of exposure, thus raising concerns about workers and public’s health risks. The major route of exposure is inhalation, but so far occupational and environmental atmosphere are not well characterized in terms of NMs. Despite the lack of epidemiological data on the relation between exposure to NMs and human health effects, their potential toxicity has been studied on cell cultures and animal models. Among these studies, most results are from in vitro experimentations due to the difficulty to perform in vivo studies for the enormous number of existing NMs and the necessity to reduce number of animals used in experimentations (3R rules). Nevertheless, results from animal experimentations remain the most reliable. Even if, pushed by the necessity to reduce the number of animals used in experimentation, new in vitro models and exposure methods are and have been developed, suggesting the more and more relevant alternatives to animal experimentation. Thus, many studies show that newly developed co-culture or 3D in vitro models have different nanotoxicity responses compared to classical mono-culture models. Moreover, studies using new devices allowing exposure of cells to aerosols of NMs show different nanotoxicity responses compared to exposure to suspensions of NMs. However, which of these models and exposure methods is more predictive for in vivo responses is yet to be defined. In order to better define which in vitro model and which exposure method is more predictive for in vivo pulmonary nanotoxicity data, three different methodologies will be implemented