Christopher Weis, PhD, DABT retired in 2021 from his position as the Senior Advisor and Toxicology Liaison for the Director of the National Institute of Environmental Health Sciences (NIEHS). Prior to joining NIEHS in 2010, Dr. Weis served as EPA's Senior Forensic Toxicologist for the Office of Criminal Enforcement, Forensics, and Training (OCEFT). For more than 22 years with EPA, he provided training and operational support for federal, state, and tribal first responders during federal emergency response actions nation-wide. Dr. Weis completed his Ph.D. in Toxicology and Medical Physiology at Michigan State University in 1989 and was awarded two consecutive NIH fellowships at the University of Virginia School of Medicine, Department of Physiology and Molecular Biophysics. Dr. Weis holds an adjoint professorship at the University of Colorado Health Sciences Center, and regularly lectures in toxicology at the Uniformed Services University of Health Sciences in Bethesda, MD. Dr. Weis has been a Diplomate of the American Board of Toxicology since 1992 and retired from his position as the President of the Board of 2018 Dr. Weis now operates a small consulting business in public health and occupational toxicology from his home in Bethesda, Maryland.