Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Internet Explorer is no longer a supported browser.

This website may not display properly with Internet Explorer. For the best experience, please use a more recent browser such as the latest versions of Google Chrome, Microsoft Edge, and/or Mozilla Firefox. Thank you.

Your Environment. Your Health.

Scientists & Staff

National Toxicology Program Division - Associate Director's Office

Associate Director

Brian Berridge
Brian R. Berridge, D.V.M., Ph.D., D.A.C.V.P.
Associate Director, National Toxicology Program
Scientific Director, National Toxicology Program Division

Tel 984-287-3111

Deputy Division Directors

Nigel J. Walker, Ph.D., D.A.B.T.
Nigel J. Walker, Ph.D.
Deputy Division Director for Research

Tel 984-287-3204
Fax 301-451-5596
Mary S. Wolfe, Ph.D.
Mary S. Wolfe, Ph.D.
Deputy Division Director for Policy, Director, Office of Liaison, Policy, and Review

Tel 984-287-3209
Fax 301-451-5759

Senior Scientist

John R. Bucher, Ph.D.
John R. Bucher, Ph.D.
Deputy Division Director for Analysis
Senior Scientist

Tel 984-287-3116
Fax 919-541-4255


Beth Perry
Beth M. Perry

Tel 984-287-3220
Lisa A. Wolf
Lisa A. Wolf
Program Specialist

Tel 984-287-4035

Toxicology Liaison

Christopher Weis, Ph.D., D.A.B.T.
Christopher P. Weis, Ph.D.
Toxicology Liaison

Tel 301-496-3511
to Top