The Food Quality Protection Act of 1996 requires EPA to reassess all previously approved pesticide tolerances by August, 2006. EPA issued the Interim Reregistration Eligibility Decision on June 30, 2003. On October 27, 2004, EPA published a Federal Register Notice (OPP-2003-0376). This Federal Register Notice indicated that Bayer CropScience, a registrant for technical carbaryl, had developed pharmacokinetic studies in rats to further evaluate the risk to children exposed to carbaryl following lawn treatment with liquid formulation. The purpose of the current document is to briefly summarize background information regarding the metabolic profile for carbaryl, the animal pharmacokinetic studies, and the proposed extrapolation approach.