Arthur L. Craigmill, PhD Toxicology Specialist Department of Environmental Toxicology University of California-Davis Jim Riviere, DVM, PhD Burroughs Wellcome Distinguished Professor Director, Center for Cutaneous Toxicology and Residue Pharmacology College of Veterinary Medicine North Carolina State University Alistair I. Webb, BVSc, PhD Professor and Associate Chair Dept. of Physiological Sciences College of Veterinary Medicine University of Florida