Skip to Content


National Toxicology Program; Office of Chemical Nomination and Selection; Announcement of and Request for Public Comment on Toxicological Study Nominations to the National Toxicology Program

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


National Institute of Environmental Health Sciences, National Institutes of Health.


Notice; request for comments.


The National Toxicology Program (NTP) continuously solicits and accepts nominations for toxicological studies to be undertaken by the program. Nominations of substances of potential human health concern are received from federal agencies, the public and other interested parties. These nominations are subject to several levels of review before selections for testing are made and toxicological studies are designed and implemented. This notice (1) provides brief background information and study recommendations regarding 15 nominations for NTP study (Table 1), (2) solicits public comment on the nominations and study recommendations, and (3) requests the submission of additional relevant information for consideration by the NTP in its continued evaluation of these nominations. An electronic copy of this announcement, Internet links to electronic versions of supporting documents for each nomination, and further information on the NTP and the NTP Study Nomination and Review Process can be accessed through the NTP Web site (​;​ select “Nominations to the Testing Program”).


Comments or information should be submitted by June 6, 2005.


Send comments or information to Dr. Scott A. Masten, Office of Chemical Nomination and Selection, NIEHS/NTP, 111 T.W. Alexander Drive, P.O. Box 12233, Research Triangle Park, North Carolina 27709; telephone: (919) 541-5710; FAX: (919) 541-3647; e-mail: Supporting documents for these nominations are available at the NTP Web site (​ select “Nominations to the Testing Program”).

Start Further Info


See contact information for Dr. Masten under ADDRESSES above.

End Further Info End Preamble Start Supplemental Information


Background Information on NTP Study Nominations and the NTP Office of Chemical Nomination and Selection

The NTP actively seeks to identify and select for study chemicals and other agents for which sufficient information is not available to adequately evaluate potential human health hazards. The NTP accomplishes this goal through a formal open nomination and selection process. Substances considered appropriate for study generally fall into two broad yet overlapping categories: (1) Substances judged to have high concern as possible public health hazards based on the extent of human exposure and/or suspicion of toxicity and (2) substances for which toxicological data gaps exist and additional studies would aid in assessing potential human health risks, e.g. by facilitating cross-species extrapolation or evaluating dose-response relationships. Nominations are also solicited for studies that permit the testing of hypotheses to enhance the predictive ability of future NTP studies, address mechanisms of toxicity, or fill significant gaps in the knowledge of the toxicity of classes of chemical, biological, or physical substances.

Study nominations may entail the evaluation of a variety of health-related effects including, but not limited to, reproductive and developmental toxicity, genetic toxicity, immunotoxicity, neurotoxicity, metabolism and disposition, and carcinogenicity in appropriate experimental models. In reviewing and selecting nominations for study, the NTP also considers legislative mandates that require responsible private sector commercial organizations to evaluate their products for health and environmental effects. The possible human health consequences of anticipated or known human exposure, however, remain the over-riding factor in the NTP's decision to study a particular substance.

Nominations undergo a multi-step, formal process of review. During the entire nomination review and selection process, the NTP works actively with regulatory agencies, its advisors, and interested parties to supplement information about nominated substances and ensure that regulatory and public health needs are addressed. The nomination review and selection process is accomplished through the participation of representatives from the National Institute of Environmental Health Sciences (NIEHS), other federal agencies represented on the Interagency Committee for Chemical Evaluation and Coordination (ICCEC), the NTP Board of Scientific Counselors—an external scientific advisory body, the NTP Executive Committee—the NTP federal interagency policy body, and the public. Study recommendations are initially developed and refined by the nominator, NTP staff, and the ICCEC. Individual study recommendations for the nominations listed in Table 1 may be further refined as the formal review Start Printed Page 23878process continues. The nomination review and selection process is described in further detail on the NTP Web site (​;​ select “Nominations to the Testing Program”).

The NTP Office of Chemical Nomination and Selection (OCNS) manages the solicitation, receipt, and review of NTP toxicology study nominations. The OCNS conducts an initial review of each study nomination received to determine whether the substance or issue has been adequately studied or has been previously considered by the NTP. For nominations not eliminated from consideration or deferred at this stage, the OCNS initiates a formal review process, as described above. The OCNS also ensures adequate background information is available to support the review for each nomination. For further information on the OCNS visit the NTP Web site ( select “Nominations to the Testing Program”) or contact Dr. Masten (see ADDRESSES above).

Request for Comments and Additional Information

The NTP invites interested parties to submit written comments or supplementary information on the nominated substances and study recommendations that appear in Table 1. The NTP welcomes toxicology and carcinogenesis study information from completed, ongoing, or anticipated studies, as well as information on current U.S. production levels, use or consumption patterns, human exposure, environmental occurrence, or public health concerns for any of the nominated substances. The NTP is interested in identifying appropriate, novel, animal and non-animal experimental models for mechanistic-based research, including genetically modified rodents and higher-throughput in vitro test methods, and as such, solicits comments regarding the use of specific in vivo and in vitro experimental approaches to address questions relevant to the nominated substances and issues under consideration. The NTP will not respond to submitted comments; however, all information received will be become part of the official record that the NTP considers in its ongoing review of these nominations. Persons submitting comments should include their name, affiliation, mailing address, phone, fax, e-mail address, and sponsoring organization (if any) with the submission. Written submissions will be made publicly available electronically on the NTP Web site as they are received (​ select “Nominations to the Testing Program”).

Start Signature

Dated: April 22, 2005.

Samuel H. Wilson,

Deputy Director, National Institute of Environmental Health Sciences.

End Signature Start Printed Page 23879

Start Printed Page 23880

Start Printed Page 23881 End Supplemental Information


[FR Doc. 05-8959 Filed 5-4-05; 8:45 am]