The Research Institute for Fragrance Materials (RIFM) is advancing a hypothesis-driven framework that could help researchers more effectively identify chemicals warranting further evaluation for respiratory sensitization.
RIFM scientists Nikaeta Sadekar, Ph.D., DABT, and Jake Muldoon, Ph.D., will present the work at LIVe2026, the Lung In Vitro event, taking place October 8-9 in Archamps, France. Their research examined the chemical reactivity and clinical characteristics of known respiratory sensitizers alongside skin sensitizers and non-sensitizing irritants.
The researchers combined clinical case reviews with TIMES in silico modeling to determine whether the different groups exhibited distinct reactivity patterns. The analysis found that respiratory sensitizers are frequently associated with bifunctional electrophilic structures capable of cross-linking proteins in respiratory tissues. By comparison, skin sensitizers and irritants are generally more readily detoxified and excreted.
Rather than treating respiratory sensitization, skin sensitization and irritation as broadly similar chemical responses, the framework points to chemical reactivity as a potential way to help distinguish substances that may warrant closer examination for respiratory sensitization.
That could provide a useful screening signal in a field where validated methods specifically designed to identify respiratory sensitizers are still lacking. RIFM says the framework is intended to make better use of existing evidence by bringing together chemical reactivity, clinical findings and in silico modeling.
The approach could help focus additional investigation on substances with characteristics associated with respiratory sensitization rather than applying the same level of scrutiny across a broader group of chemicals.
The work also points toward a broader role for mechanistic information in respiratory safety research. According to RIFM, the findings provide a scientifically grounded way to prioritize substances for further evaluation and advance non-animal assessment.
Importantly, the researchers describe the work as a framework rather than a validated screening method. Muldoon said the next step is to discuss the mechanistic distinction with scientists developing predictive respiratory models and identify opportunities to test and strengthen the framework through collaboration.
That emphasis on testing and refinement is central to the research's potential impact. If the observed reactivity patterns can be further evaluated and strengthened, they could contribute to predictive approaches for respiratory sensitization screening.
The research will be presented during LIVe2026's Inhalation Toxicity Testing session, alongside work addressing predictive lung models, inhalation toxicity testing, regulatory considerations and exposure modeling.
