The U.S. Environmental Protection Agency (EPA) announced on August 7, 2024, that it will hold a webinar on August 28, 2024, on the use of new approach methodologies (NAM). The webinar, “The CATMoS Model for Acute Oral Toxicity and Evaluation of its Potential Use in a Regulatory Context for Pesticide Hazard and Risk Assessment,” is the fifth in a series held in collaboration with PETA Science Consortium International (PSCI), the Institute for In Vitro Sciences (IIVS), and the California Department of Pesticide Regulation (CDPR). The presenters are:

• Kamel Mansouri, National Toxicology Program’s (NTP) Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM). Dr. Mansouri will present on a global project led by NICEATM and the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) Acute Toxicity Workgroup. EPA states that the goal of the project was to develop computer-based models for predicting the acute oral toxicity of chemicals. The project received 139 models that were developed using a data set of 11,992 chemicals. The models were then combined into the Collaborative Acute Toxicity Modeling Suite (CATMoS) that demonstrated performance comparable to vertebrate animal testing for predicting toxicity. According to EPA, “[t]hese models cover acute toxicity endpoints relevant to regulations and are now being evaluated for use by EPA to replace vertebrate animal studies in Agency research, regulatory, compliance and enforcement activities for chemicals and pesticides.”
• Michael Lowit, EPA’s Office of Pesticide Programs (OPP). Dr. Lowit will present on OPP’s work with multiple national and international organizations and numerous stakeholders to evaluate toxicology studies conducted for pesticides, advancing the use of NAMs in regulatory risk assessment of acute toxicity. OPP worked with NICEATM and the Humane Society to evaluate how well computer-based models predict the toxicity of conventional pesticides. CATMoS was used to predict the acute oral toxicity of EPA-registered pesticides and compared to the lethal dose identified via vertebrate animal testing. According to EPA, “[t]he results support potentially relying on CATMoS predictions instead of vertebrate animal testing in some cases.”