You are here:
Evaluation of a Proposed Approach to Refine the Inhalation Risk Assessment for Point of Contact Toxicity: A Case Study Using a New Approach Methodology (NAM)
Citation:
Evaluation of a Proposed Approach to Refine the Inhalation Risk Assessment for Point of Contact Toxicity: A Case Study Using a New Approach Methodology (NAM).
Impact/Purpose:
The Agency is soliciting advice from the FIFRA Scientific Advisory Panel (SAP) on the derivation of the POD from the in vitro assay and the integration of the in vitro POD for calculation of human equivalent concentrations for the inhalation risk assessment. Chlorothalonil will be presented as a case study to solicit advice on the proposed overall approach expected to be applied to other pesticides or industrial chemicals in the future.
Description:
New approach methodologies (NAMs) has been adopted as a broadly descriptive reference to any non-animal technology, methodology, approach, or combination thereof that can be used to provide information on chemical hazard and risk assessment. An example of a NAM for refining inhalation risk assessment has been submitted to the Agency for the pesticide chlorothalonil. Chlorothalonil is a contact irritant that has been found to be toxic via the inhalation route. Due to the irritant nature of chlorothalonil and animal welfare concerns, the registrant (Syngenta Crop Protection) indicated that a 90-day inhalation toxicity study was not feasible to fulfill the regulatory requirement of a subchronic inhalation study. Subsequently, Syngenta proposed an alternative approach using an in vitro assay (MucilAir TM using human nasal tissue) to characterize the hazard of chlorothalonil and derive a point of departure (POD) for use in human health risk assessment. In order to calculate human equivalent concentrations for the purposes of human health risk assessment, an in vitro POD has been proposed in conjunction with surface concentrations of deposited chlorothalonil particles from a computational fluid dynamic (CFD) model for the upper airway of a human. As a proof of concept, Syngenta also used the calculated human equivalent concentrations for pesticide operators/applicators to provide potential risk estimates supported by this proposed approach.
URLs/Downloads:
Transmission of Background Materials and Charge (PDF, NA pp, 36 KB, about PDF)Meeting Materials for the December 4, 6-7, 2018 SAP
Issue Paper; Evaluation of a Proposed Approach to Refine Inhalation Risk Assessment for Point of Contact Toxicity: A Case Study Using a New Approach Methodology (NAM) (PDF, NA pp, 366 KB, about PDF)
Peer Review Plan (PDF, NA pp, 40 KB, about PDF)
Meeting Minutes and Final Report No. 2019-01 (PDF, NA pp, 1249 KB, about PDF)
Charge to the FIFRA SAP (PDF, NA pp, 33 KB, about PDF)