Human are estimated to be exposed to nearly a thousand micro- and nanoplastics (MNPs) per day via ingestion and inhalation. Recent in vitro studies demonstrated the ability of MNPs to cross respiratory epithelial cell layers. Consequently, MNPs have been detected in human blood, intestinal tissue and placenta. MNPs have been associated with inflammation, oxidative stress and metabolic disturbances in vivo in zebrafish and mice. However, the knowledge on the impact of MNPs on the human airway/lung epithelium is limited. In our study, we elucidated whether or not polystyrene (PS) MNPs exert toxic effects on cells that comprise the lung/airway epithelial barriers. Cupper (II) Oxide (CuO) and Titanium dioxide (TiO2) NPs of the same size served as control particles. We characterised suspensions of PS and control particles using dynamic light scattering. Thereafter, Air-liquid interface (ALI) models were established composed of either A549 cells or differentiated primary bronchial epithelial cells (PBECS; provided by PLUC facility MUMC+) from healthy donors. Both models were exposed for 24 hours to different doses of PS or control particles. Read-out parameters included cytotoxicity and inflammatory response. None of the exposures caused an increase of cell death compared to the vehicle control. Moreover, transcript levels of inflammatory genes and IL8 protein secretion was not changed in cultures exposed to PS or TiO2 particles. In contrast, CuO exposure resulted in an increase of both IL8 protein secretion and transcript levels, in a dose-dependent manner. These results show that PBECs and A549 ALI cultures are suitable to determine toxic effects of NPs exposure. The particles used might not be realistic for the diverse scale of MNPs present in the environment. Therefore, in the near future we will determine dose-response relationships of environmentally-relevant MNPs on toxic parameters, which is crucial as input for assessing risks of these particles to human health.