Wilma Bergfeld, M.D.
Chairperson
Dr. Bergfeld completed her undergraduate work at the College of William and Mary in Williamsburg, Virginia, and is a graduate of the Temple University School of Medicine in Philadelphia. She did her dermatology residency at the Cleveland Clinic and her dermatopathology fellowship at the Armed Forces of Pathology in Washington, DC. She joined the Cleveland Clinic as a Clinical Dermatologist, Department of Dermatology and, later, after an AFIP Dermatopathology Fellowship, she was appointed as Head and Co-Director of Dermatopathology, Departments of Dermatology and Pathology. She has been the Director of the Cleveland Clinic’s Dermatopathology fellowship since 1975. Dr. Bergfeld has also served on, and led, numerous professional and scientific associations and committees, including the US Food and Drug Administration’s Dermatology and Ophthalmology Advisory Committee and the Device Advisory Committee. She was appointed to the Expert Panel for Cosmetic Ingredient Safety in 1977, and became the Chairperson of this Panel in 1991.
Donald V. Belsito, M.D.
Team Leader
Dr. Belsito completed his undergraduate work at Georgetown University, Washington, DC, and is a graduate of the Cornell University Medical College in New York. He did his dermatology residency and dermatologic immunology fellowship at the New York University Medical Center. He joined Columbia University as the Leonard C. Harber Professor, Department of Dermatology in 2011. Dr. Belsito has also served on, and led, numerous professional and scientific associations and committees, including the American Contact Dermatitis Society and the Expert Panel for Fragrance Safety. He was appointed to the Expert Panel for Cosmetic Ingredient Safety, as a team leader, in 1991.
David E. Cohen, M.D.
Team Leader
Dr. Cohen completed his undergraduate work at the City University of New York, and is a graduate of the State University of New York at Stony Brook, School of Medicine (M.D.) and Columbia University School of Public Health (M.P.H.). He did his dermatology residency at the New York University Medical Center and Columbia University School of Public Health. He joined the NYU School of Medicine in 1994, and is currently Chief - Allergy Section/Contact Dermatitis, Director - Occupational and Environmental Dermatology, Vice Chairman - Clinical Affairs, & Director of Dermatology Faculty Practice - Dermatologic Associates and Dermatologic Surgical Associate. Dr. Cohen has also served on, and led, numerous professional and scientific associations and committees, including the American Contact Dermatitis Society, the International Eczema Council, the American Dermatological Association, & the American Academy of Dermatology. He was appointed to the Expert Panel for Cosmetic Ingredient Safety, as a team leader, in 2020.
Samuel M. Cohen, M.D., Ph.D.
Dr. Cohen completed his undergraduate degree, Ph.D., and M.D. at the University of Wisconsin (Madison), and served a residency in anatomic and clinical pathology at St. Vincent Hospital and University of Massachusetts Medical School in Worcester, MA. He joined the University of Nebraska Medical Center in 1981 as Professor in what is now the Department of Pathology, Microbiology, and Immunology and the Buffett Cancer Center. He served as Vice Chair (1981-1992) and Chair (1992-2007) of the department, and is the Havlik-Wall Professor of Oncology. He has served and lead numerous national and international boards and committees, including the Board of Scientific Counselors of the National Toxicology Program and the National Institute of Environmental Health Sciences, the Science Advisory Board of the U.S. EPA, and the Expert Panel for the evaluation of flavor ingredients. He was appointed to the Expert Panel for Cosmetic Ingredient Safety in 2025.
Curtis D. Klaassen, Ph.D.
Dr. Klaassen completed his undergraduate work at Wartburg College, Waverly, Iowa, and received his Ph.D. in Pharmacology from the University of Iowa. He joined the University of Kansas Medical Center in 1968 where he spent over 45 years holding numerous positions, including University Distinguished Professor and Chair of the Department of Pharmacology, Toxicology, and Therapeutics. He has made outstanding contributions to the toxicological sciences and is one of the most highly sited toxicologist in the world. Dr. Klaassen has served on the editorial boards of many journals, including Toxicological Science (inaugural Editor-in-Chief), and has been the editor of several books, including Casarett and Doull's Toxicology: The Basic Science of Poisons. He served on, and led, numerous professional and scientific associations and committees, including the Society of Toxicology (President, 1990-91) and the International Union of Toxicology (President, 1992-95). He was appointed to the Expert Panel for Cosmetic Ingredient Safety in 1993.
Allan Rettie, Ph.D.
Dr. Rettie completed his undergraduate work with honors (Pharmacy) at Heriot-Watt University, Edinburgh, Scotland, and is a graduate (PhD, Pharmaceutical Sciences) of the University Newcastle-upon-Tyne, England. He then proceeded to the University of Washington in Seattle, first as Senior Research Fellow in the Department of Pharmacology and ultimately as a faculty member in the Department of Medicinal Chemistry, which he chaired from 2000 to 2014. Dr. Rettie has served on the editorial boards of numerous scientific journals and NIH grant review panels. He has chaired the Scientific Affairs Committee of the International Society for Study of Xenobiotics (ISSX) and the International Union of Basic and Applied Pharmacology’s Section of Drug Metabolism and Transport. He was appointed to the Expert Panel for Cosmetic Ingredient Safety in 2022
David Ross, Ph.D.
Dr. Ross completed his undergraduate and graduate work (in pharmacy and pharmaceutical sciences) at the University of Aston, Birmingham, UK and at the Medical Research Council Toxicology Unit in the UK. He was a Royal Society Postdoctoral Fellow at the Karolinska Institute in Stockholm, Sweden, and a Research Associate at the University of California in Berkeley, California. Dr. Ross joined the School of Pharmacy at the University of Colorado as an Assistant Professor and proceeded through the ranks to Professor with tenure and serving as Director of Graduate Studies. He was a visiting professor at the Medical Research Council Toxicology Unit, UK during this period. He was appointed as Chairman of the Department of Pharmaceutical Sciences in 1995 and served in that role for 27 years. He is currently the Associate Dean for Research and Graduate Studies at the Skaggs School of Pharmacy and Pharmaceutical Sciences. He has made outstanding achievements in, and contributions to, the chemical and toxicological sciences. He has served as President of the Mountain West Region of the Society of Toxicology and President of the Mechanisms Section of the national Society of Toxicology. He has served on the editorial boards of several journals and on numerous NIH and international grant review panels. He has also served as a member of the International Agency Research Cancer (World Health Organization) expert panel for evaluation of carcinogenic risks to humans. Dr. Ross’ research program has focused on the role of the quinone reductase family of enzymes in mechanisms of toxicity and exploitation of these enzyme systems for drug discovery. He was appointed to the Expert Panel for Cosmetic Ingredient Safety in 2022.
Paul William Snyder, D.V.M., Ph.D.
Dr. Snyder completed his undergraduate work at the Iowa State University, Ames, Iowa, and received his Doctor of Veterinary Medicine from the Iowa State University College of Veterinary Medicine, also in Ames. He attended the University of Illinois (Department of Veterinary Pathobiology), Champaign-Urbana, Illinois, for his pathology residency, and then attended the Purdue University Department of Veterinary Pathobiology, in West Lafayette, Indiana, where he earned a Ph.D. in immunology. Dr. Snyder received a faculty position at Purdue University, where he did investigative research and teaching. He joined the Department of Veterinary Pathobiology at Purdue University in 1994, ultimately climbing the ranks to Professor, and simultaneously becoming the Director of the Purdue Histology and Phenotyping Laboratory. He is currently Senior Pathologist and Manager of Experimental Pathology Laboratories, Inc., Midwest. Dr. Snyder has also served on, and led, numerous professional and scientific associations and committees, including the FDA Non-Clinical Studies Section Vasculitis Expert Working Group and the Society of Toxicologic Pathology. He was appointed to the Expert Panel for Cosmetic Ingredient Safety in 1999.
Susan Tilton, Ph.D.
Dr. Tilton completed her undergraduate work (biology) at Duke University, Durham, North Carolina, and is a graduate of the Ole Miss School of Pharmacy (MS Pharmacology) in Oxford, Mississippi, and of the Oregon State University, College of Agricultural Sciences (PhD Toxicology) in Corvallis, Oregon. She did her postdoctoral fellowship at the Fred Hutchinson Cancer Research Center, Seattle, Washington. Before returning to academia, Dr. Tilton joined the Pacific Northwest National Laboratory in Richland, Washington as Computational Biology & Bioinformatics Senior Research Scientist. She then returned to her doctorate alma mater as an Assistant Professor, quickly rising up to tenure. In addition to her role as an Associate Professor of Environmental and Molecular Toxicology, Dr. Tilton is currently the Director of Academic Programs in the same college. She has made outstanding achievements in, and contributions to, the chemical and toxicological sciences, and was accordingly appointed President of the Pacific Northwest Association of Toxicologists in 2017. Dr. Tilton has been invited and served on numerous National Institute of Environmental Health Sciences / National Institute of Health scientific review panels. She was appointed to the Expert Panel for Cosmetic Ingredient Safety in 2022.