National Toxicology Program

The review and selection of substances and issues nominated for study is a multi-step process. A broad range of concerns are addressed during this process through the participation of representatives from the NIEHS, other Federal agencies, the NTP Board of Scientific Counselors, the NTP Executive Committee, and the public. This multi-step evaluative process provides the NTP with direction and guidance to ensure that its testing program addresses toxicological concerns relative to all areas of public health, and furthermore, that there is balance among the types of substances selected for study (e.g., industrial chemicals, consumer products, therapeutic agents). As such, it should be recognized that at any given time, the new study nominations under consideration do not necessarily reflect the overall balance of substances historically or currently being evaluated by the NTP in its toxicology testing program.

Nominations are reviewed by the NTP Office of Nomination and Selection to determine whether the substance has been adequately tested or has been previously considered by the NTP. For nominations not eliminated from consideration or deferred at this stage, the available information on the substance is examined in detail to prepare a Review of Toxicological Literature which evaluates and summarizes the relevant data for each substance. The Review of Toxicological Literature serves as the supporting document of record for the nomination and addresses the types of information found in the NTP Study Nomination Elements. In some cases, supporting documents are prepared by the nominator and submitted along with the nomination

The nomination supporting documents along with relevant information supplied by the nominator are distributed to the Interagency Committee for Chemical Evaluation and Coordination (ICCEC). The ICCEC is composed of representatives from the Agency for Toxic Substances and Disease Registry/ National Center for Environmental Health, U.S. Consumer Product Safety Commission, U.S. Department of Defense, U.S. Environmental Protection Agency, U.S. Food and Drug Administration's National Center for Toxicological Research, National Institutes of Health's (NIH) National Cancer Institute, NIH's National Institute of Environmental Health Sciences (NIEHS), National Institute for Occupational Safety and Health, and the Occupational Safety and Health Administration. The ICCEC meets once or twice annually to evaluate groups of new study nominations and to make recommendations with respect to both specific types of toxicological studies and testing priorities.

A Federal Register notice is published listing the new study nominations and corresponding preliminary study recommendations. The Federal Register notice marks the beginning of a formal public comment period and solicits comments on the nominations and study recommendations from interested parties including information on completed, ongoing, or planned testing in other government organizations and the private sector.

To facilitate review of nominations by the NTP Board of Scientific Counselors (BSC) and the public, NTP staff develop draft research concept documents for each nomination recommended for in-depth study. A research concept is a brief document outlining the nomination or study rationale, and the significance, study approach, and expected outcome of a proposed research program tailored for each nomination. The purpose of these research concept documents is to outline the general elements of a program of study that would address the specific issues that prompted the nomination, but also encompass studies that may address larger public health issues, or topics in toxicology that could be appropriately addressed through studies on the nominated substance or issue.

Nomination supporting documents, draft research concept documents, and any public comments received on the nominations are then presented to the NTP Board of Scientific Counselors for review and comment in a public meeting. This public meeting also provides and opportunity for the NTP to receive additional public comments. The Board provides independent advice to the NTP on the merit and priority of proposed studies for each nomination, and may suggest additional studies as well as offer their perspective on issues raised by public comments.

All information on each nomination gathered to this point is then provided to the NTP Executive Committee. The Executive Committee reviews each nomination and makes a final recommendation to the NTP Director on whether to proceed with or defer the studies recommended for each of the nominations.