The functional observational battery in rats – Results from a positive control study to support crop protection and chemical safety studies

SOT 2026 -- The functional observational battery (FOB) is a structured assessment of an animal’s appearance, behavior and responses to stimuli. Regulatory guidelines from agencies such as the US EPA and OECD require laboratories conducting neurotoxicity and developmental neurotoxicity studies to periodically validate their procedures using positive control substances. Positive control studies confirm the sensitivity and reliability of the testing methods, equipment and personnel, especially when key elements change. Positive control studies also help demonstrate technician expertise and inter-observer reliability. Guidelines including EPA OPPTS 870.6200, 870.6300, OECD 424, OECD 443 and OECD Guidance Document No. 43 emphasize the need to detect both increases and decreases in behavioral performance. This work was designed to demonstrate that the FOB procedure at Labcorp is suitable for performing regulatory neurotoxicity assessments and to confirm its suitability for detecting chemically induced behavioral changes across rat strains.