About Dr. Koonce
Dr. Nathan A. Koonce is a Project Toxicologist with more than 10 years of experience in applied toxicology, regulatory research and product safety. He supports private and public sector clients with environmental toxicology, risk assessment of complex substances, regulatory strategy and the development of alternative testing approaches.
At Onterris, Dr. Koonce applies this expertise to toxicological evaluations, product safety assessments, regulatory strategy and litigation support. He develops environmental sampling and analysis plans, interprets complex toxicological data and contributes to international consensus standards and alternative testing strategies. As a member of the Onterris Toxicology Emergency Response Program (TERP), he leads air monitoring and environmental sampling teams during chemical emergencies, providing critical data to support worker and community safety. His experience bridges laboratory science, regulatory frameworks and field operations to help clients address complex environmental and occupational health challenges.
Dr. Koonce earned a Bachelor of Arts (B.A.) in Chemistry from the University of Arkansas, a Master of Science (M.S.) in Pathology and a Doctor of Philosophy (Ph.D.) in Interdisciplinary Biomedical Sciences from the University of Arkansas for Medical Sciences. His doctoral research focused on novel theranositcs, examining vascular hypoxia and its implications for human health. He completed his postdoctoral training at the National Center for Toxicological Research and subsequently stayed on as a staff scientist for 10 years where his research focused on safety and efficacy of emerging therapeutics, safety of consumer products, and safety of novel food additives.
Dr. Koonce is a member of the Society of Toxicology and the American Industrial Hygiene Association. He has contributed to over 20 research publications and served as a reviewer for peer-reviewed journals.
