In Vitro Inhalation Toxicity Assay of Azoxystrobin 23% SC and Spinetoram 11.7% SC using EpiAirwayTM

Inhalation is one of the major routes for the evaluation of hazards of a xenobiotic since the lung is an important route for exposure of chemicals and crop protection products. Crop protection products, such as Azoxystrobin 23% SC and Spinetoram 11.7% SC, could potentially induce damage to the respiratory tract following exposure to the spray by an operator or bystander via the inhalation route. Inhalation toxicity testing is used to identify potential hazards for such products. Conventionally, this was assessed using OECD Test Guideline Nos. 403, 412, 413, 433 or 436. NAMs for respiratory toxicity have been accepted by the US EPA1 and highlighted in an OECD Case Study2. The MatTek EpiAirway™ Model (AIR-100) was developed to assess the inhalation hazards of xenobiotics. The human EpiAirway™ Model test system closely mimics the histological, morphological, biochemical and physiological properties of the human airway epithelium. The tissue construct consists of a ciliated apical surface, mucociliary epithelium, on a microporous membrane. This model is used as a part of the forward-looking JRF strategy to explore alternative tests in compliance with the principles of the 3Rs. Azoxystrobin 23% SC and Spinetoram 11.7% SC were chosen as the test articles, since they have known respiratory hazards. The formulate products, rather than the active ingredients alone, were chosen since these are the products to which an operator or bystander may be exposed via the inhalation route. This assay addresses the human health endpoint inhalation toxicity. It makes use of the human EpiAirway™ which closely mimics the histological, morphological, biochemical, and physiological properties of the human upper airway epithelium. EpiAirway™ is a commercially available functional model of the human upper airway epithelium containing a ciliated apical surface, mucociliary epithelium and microporous membrane.

EpiAirway AIR-100, respiratory irritation, Azoxystrobin, Spinetoram, formaldehyde, suspension concentrate, TEER, LDH, MTT, histology, loss of cell layers, apoptosis, necrosis, LOAEL, lowest observed adverse effect level, crop protection, pesticide

Azoxystrobin, Spinetoram, formaldehyde