John Lipscomb is a senior toxicologist for CTEH®, LLC. His scientific career began in 1984 at the bench as a Principal Investigator at the National Center for Toxicological Research (U.S. FDA, Jefferson, AR). There, he completed research requirements for his Master’s and Doctorate degrees by performing experiments to characterize the adult and transplacental pharmacokinetics of trimethyltin, a potent neurotoxicant. Later his studies expanded to include mechanistic and enzyme inhibition. In 1991, Dr. Lipscomb began active duty service in the U.S. Air Force, posted at Wright-Patterson AFB in Dayton, Ohio. Dr. Lipscomb supported investigations into the pharmacokinetics of mission-critical compounds, like trichloroethylene and halon replacement chemicals. His work pioneering the military’s first large-scale investigation of human metabolic variability earned him the Air Force Achievement medal. During his time at the Air Force, his Metabolism Section produced 15 peer-reviewed government technical reports. Following completion of active duty in 1998, he accepted a position in the EPA’s National Center for Environmental Assessment in Cincinnati, in the Division in which EPA’s Integrated Risk Information System (IRIS) originated and was maintained until 2000. 

While at the EPA, Dr. Lipscomb initially undertook toxicology and dose-response responsibilities on a project aimed at quantifying the negative health impact of drinking water disinfection byproducts in comparison to the positive health impact of avoiding microbially-induced disease. He was invited to join the the Division’s work in chemical mixtures, where he was the sole toxicologist contributing to EPA’s guidances on chemical mixtures and cumulative risk. These guidances were developed specifically for application at Superfund sites. Dr. Lipscomb also served as Chemical Manager for several IRIS assessments, and developed several Provisional Peer-Reviewed Toxicity Value (PPRTV) assessments specifically requested by the EPA’s Office of Land and Emergency Response. Following an internal transfer to the EPA’s National Homeland Security Research Center (NHSRC), Dr. Lipscomb assumed overall responsibility for its Provisional Advisory Levels (PALs) program, initiated in 2004. Dr. Lipscomb was responsible for the development of acute and short-term exposure guidance values for oral and inhalation exposures to hazardous substances and chemical warfare agents. He developed and lectured in several continuing education courses taught locally, regionally, nationally and internationally on topics of toxicology and health risk assessment. During his time at the EPA, Dr. Lipscomb authored or co-authored 25 peer-reviewed government technical reports. 

Dr. Lipscomb holds certification in general toxicology as a Diplomate of the American Board of Toxicology. His contributions to the field of toxicology led to his recognition as a Fellow of the Academy of Toxicological Sciences in 2008. Dr. Lipscomb serves on the Health Advisory Board for NSF International, an organization which certifies devices, appliances, and equipment-contacting drinking water. He also serves on AIHA’s Emergency Response Planning Committee. He is a past president of the Ohio chapter of the Society for Risk Analysis and the Society of Toxicology, has served on Council for the Society of Toxicology, and is a past president of the American Board of Toxicology. He is on the editorial board and is a former Associate Editor for Toxicological Sciences and is an Associate Editor for Toxicology Mechanisms and Methods and Toxicology Reports. Dr. Lipscomb maintains an Adjuct Professorship in the Department of Pharmacology and Toxicology at the University of Louisville, where he is course director for a graduate level course, Introduction to Health Risk Assessment.