Edited byShayne Cox Gad, PhD, DABT, is the principal of Gad Consulting Services in Raleigh, North Carolina. He has more than 38 years of broad-based experience in toxicology, drug, device development, document preparation, statistics, and risk assessment, having previously been the director of toxicology and pharmacology for Synergen, director of medical affairs technical support system services for Becton Dickinson, and senior director of product safety and pharmacokinetics for G.D. Searle. He is past president of the American College of Toxicology and Roundtable of Toxicology Consultants and a board-certified toxicologist. Dr. Gad has published 47 books and more than 350 chapters, papers, and abstracts.