Guidance on the Up-and-Down Procedure Data Evaluation

The Department of Pesticide Regulation (DPR) evaluates the results from acute oral toxicity testing data when registering pesticides for use in California. This testing data is used to analyze the magnitude of acute toxicity (derived from the LD50 value¹) and to assign the acute oral Toxicity Category² to pesticidal active ingredients and formulated end-use products. One methodology for generating acute oral toxicity data is the Up-and-Down Procedure (UDP). This notice provides guidance to applicants for submitting acute oral toxicity data using the UDP methodology in cases of partial survival when the reported LD50 point estimate falls between 450 – 550 mg/kg.