IIVS and the Research Institute for Fragrance Materials (RIFM) have initiated a collaboration to develop tests designed to assess potential respiratory allergens. Developing a reliable, in vitro assay to assess the allergenicity of materials to the airway tract has been an area of active research for well over a decade, however most efforts have resulted in poor accuracy and the inability to distinguish airway sensitizers from irritants. By combining the extensive expertise and knowledge base in the field of respiratory toxicology of both organizations, we are confident that an assay can be developed to robustly assess this endpoint.