Mark S. Johnson, Ph.D., DABT, Fellow ATS  Director, Toxicology, US Army Public Health Center, Aberdeen Proving Ground, MD, USA Dr. Johnson currently serves as the Director of Toxicology, US Army Public Health Center at Aberdeen Proving Ground, MD where he is responsible for the operational and technical arm of the Army Surgeon General and the Assistant Secretary of the Army for toxicological matters. He has worked extensively in the evaluation of the toxicity of military unique compounds and development and evaluation of a phased approach to the gathering toxicity data for new compounds under development. He has authored over 100 peer-reviewed publications, book chapters, and technical reports and serves on several NATO and EPA panels. He has been a member of Society of Environmental Toxicology and Chemistry (SETAC) since 1997 and is a past Steering Group Member of the Wildlife Toxicology World Interest Group, past chair of Ecological Risk Assessment World Interest Group, and a member of the World Science Committee for SETAC and SETAC North America. Dr. Johnson is also a member of the International Board of Environmental Risk Assessors (IBERA). He has been a member of the Society of Toxicology since 2009. Dr. Johnson is a fellow of the Academy of Toxicological Sciences, Chair of the Tri-Service Toxicology Consortium (TSTC), past Steering Committee Chair of the Joint Army-Navy-NASA-Air Force (JANNAF) Propulsion Committee, Subcommittee on Safety and Environmental Protection, the past president of the American Board of Toxicology (ABT). 　 Michael Quinn, Jr., Ph.D. Chief, Health Effects Division, Toxicology Directorate, US Army Public Health Center, Aberdeen Proving Ground, MD, USA 　 Michael Quinn, Jr., Ph.D., is the U.S. Army Public Health Center's Health Effects Division Chief for the Directorate of Toxicology. He has contributed to numerous toxicology studies at the APHC with explosives and propellants in a wide range of taxa that has included mammals, birds, reptiles, and amphibians. His areas of expertise are developmental and reproductive toxicology and endocrine disruption. Dr. Quinn's primary passion is method development, and he has aided in developing an avian two-generation toxicity test for the U.S. Environmental Agency’s Endocrine Disruptor Screening Program’s Tier 2 battery of tests. Currently, he is leading a series of toxicity assessments for per- and polyfluoroalkyl substances (PFAS) associated with contamination from aqueous film-forming foam (AFFF) use and for PFAS-free AFFF replacements. 　 Allison M. Narizzano, Ph.D. Biologist, Toxicology, US Army Public Health Center, Aberdeen Proving Ground, MD, USA Dr. Narizzano is a Biologist at the US Army Public Health Center at Aberdeen Proving Ground, MD. She completed her Ph.D. in Toxicology at the University of Maryland in 2020. In her doctoral work, Dr. Narizzano evaluated the effects of defense-relevant chemicals, including PFAS and insensitive munitions, on non-traditional laboratory models. 　 　 Marc A. Williams, Ph.D., Fellow AAAAI , Biologist, Directorate of Toxicology, US Army Public Health Center, Aberdeen Proving Ground, MD, USA 　 Dr. Williams is a Biologist (immunotoxicologist) and serves as a Project Manager for the Wildlife Toxicity Assessment Program, Toxicology Directorate – Health Effects Division where he provides leadership and subject matter expertise in applied toxicology, and environmental toxicity assessments of Military unique chemicals of interest that include PFAS, Nanomaterials, Particulate Matter and Complex Chemical Mixtures. Dr. Williams has previously served as a Research Biologist at the U.S. Environmental Protection Agency (U.S. EPA), with research interests in human health and toxicological exposures impacting wellness and protective immune competence. Prior to joining the U.S. EPA, Dr. Williams was an Assistant Professor of Medicine and Environmental Medicine at the University of Rochester School of Medicine and Dentistry, New York, and an Instructor of Medicine at the Johns Hopkins University School of Medicine where he led research programs in human immunology, applied toxicology and models of human disease. Dr. Williams holds primary degrees first in Molecular Biotechnology and Process Bioengineering, and second in Molecular Cell Biology and Immunology. Dr. Williams earned his Ph.D. in Hematological Oncology and Cancer Immunology from Queen Mary College, University of London, U.K. Dr. Williams is a Fellow of the American Academy of Allergy, Asthma and Immunology (AAAAI) and served on their Special Emphasis Working Group to highlight the importance of nanoparticle toxicology in human disease pathways. Dr. Williams has authored over 100 peer-reviewed articles, review papers, book chapters, book titles, and formal scientific reports. Dr Williams serves on several ad hoc grant review panels for NASA aligned to their Atmospheric, Earth and Environmental Health Research Panels, and currently serves as the Non-VA Federal Government Chair of the Intergenerational Health Effects of Military Exposures Work Group. Dr. Williams is a member of the Society of Environmental Toxicology and Chemistry (SETAC) North America (SNA) and the Society of Toxicology (SOT). He actively serves on the Membership Committee (MC) of SNA and as MC liaison to the Development Committee of SNA. For the past six years, Dr. Williams has served a leading role on the National Cancer Institute/NIH Nanomaterials Working Group, and for past three years as the current Editor in Chief of Drug and Chemical Toxicology and for 10 years as a Regular Editorial Advisory Board Member of Toxicology Letters.