Toxic pulmonary exposures can lead to acute (e.g.irritation) or chronic (e.g.fibrosis) effects that can have a profound impact on the individual.Understanding the effects of materials on the respiratory system is a large challenge considering the complexity of exposures and the structures and function of the lung itself.We at IIVS employ current model systems of respiratory tissue that offers a wide scope of testing capabilities, ranging from screening activities to in-depth evaluation of acute and chronic changes in viability and pulmonary tissue function.Traditional cell cultures (cell lines and primary cells) and 3-dimensional (3D) tissues including reconstructed airway grown at the air-liquid-interface and precision-cut lung slices obtained from human donor tissue are part of IIVS portfolio of models to assess toxicants, including modified risk tobacco products such as E-cigarettes.Increases in cytotoxicity, changes in viability, expression of inflammatory cytokines, and ciliary beat frequency can be detected within hours or days of exposure.Our complex, long-term models also allow the evaluation of chronic changes such as prolonged inflammation, collagen deposition, Goblet cell hyperplasia, activation of resident macrophages, tissue restructuring, etc.that require weeks to manifest.We employ modem assays and methods to best assist our collaborators and clients when evaluating materials that have the potential to cause harm to the respiratory system.IIVS can provide CRO support for products under development using GLP-compliant, non-animal methods in an unparalleled manner.