National Toxicology Program

National Toxicology Program

Nominations in Review 2010

Substances studied by NTP are selected primarily on the basis of production levels, known or anticipated human exposure, suspicion of toxicity based on chemical structure or existing health effects data, availability of adequate toxicological data, and the extent of public concern. Selection of a substance for study does not imply that the substance is hazardous to humans or toxic/carcinogenic to laboratory animals. Likewise, when nominated substances are not selected for toxicological evaluation by NTP, this should not be taken to mean that the substance is not a potential human health hazard. Nominated substances in the table below are identified by a common or generic name and CAS Registry Number where appropriate.

Learn more about NTP Study Types.

For information, questions or comments, contact:

Dr. Scott A. Masten
Director, Office of Nomination and Selection
Division of the National Toxicology Program
National Institute of Environmental Health Sciences

P.O. Box 12233, MD K2-02
Research Triangle Park, NC 27709
919-541-5710 (voice)
301-451-5599 (fax)



Back to top

Nomination Source Nomination Rationale* Proposed Studies**
Draft Research Concept
Nomination support document
NIEHS High production and use as a plasticizer in industrial and consumer product; lack of adequate toxicological data; suspicion of toxicity based on limited toxicity studies in rodents and the presence of structural features which suggestive of potential hazard
  • In vitro toxicity studies to assess potential for endocrine activity and neurotoxicity
  • ADME and toxicokinetics studies
  • Subchronic toxicity studies including assessments of reproductive, developmental, immune and neurologic toxicity
  • Chronic toxicity and carcinogenicity studies
Drinking water disinfection by-products: HMG-CoA reductase inhibition and developmental toxicity; Interactive effects of antilipidemic agents and drinking water contaminants in producing developmental toxicity
Draft Research Concept
Private Individual Co-occurrence in drinking water of therapeutic drugs, environmental contaminants and disinfection by-products with known developmental and/or reproductive toxicities; inadequate data to understand potential hazard of mixed exposures
  • Mechanistic studies to explore individual and interactive effects of prenatal exposure to agents that modulate cholesterol and lipid pathways
  • A tiered program of mixture studies to include other drinking water contaminants that affect lipid pathways and produce developmental toxicities by similar but different modes of action
Draft Research Concept
Nomination support document
Private Individual
Long term safety concern when used as therapy for sickle cell anemia; NTP Center for the Evaluation of Risks to Human Reproduction (CERHR) Expert Panel identified a critical data need for multi-generation experimental animal studies to assess the long-term effects of prenatal and postnatal exposures on postnatal development including developmental neurotoxicity, reproductive function, and carcinogenicity
  • Multigenerational developmental and reproductive toxicity studies including neurotoxicity and immunotoxicity assessments
  • Carcinogenicity studies
Isoflavones in soy infant formula
[no CAS No.]
Draft Research Concept
NIEHS Widespread exposure and concern for potential adverse effects on human development; address certain critical data gaps and research needs identified in the NTP Center for the Evaluation of Risks to Human Reproduction (CERHR) Expert Panel Report on Soy Infant Formula
  • Studies to determine the feasibility of direct oral administration of soy infant formula to rodents (rats and/or mice) during the period of lactation
  • Reproductive development and fertility study in rodents with soy infant formula and a mixture of isoflavones at the ratio found in soy infant formula (oral administration to pups during period of lactation)
  • Uterotrophic assay to assess interactions among the individual isoflavones in soy infant formula Pharmacokinetic studies to assess metabolism of daidzin to equol during the period of lactation
*The rationale for the nomination is provided by the nominator and is summarized here to be consistent with the NTP Nomination Principles and the selection factors stated above.
**Recommendations for proposed studies are initially developed by NTP staff based on needs identified by the nominator and review of all relevant information. Study recommendations are further refined based on comments received during interagency and Board of Scientific Counselors review of the nomination and draft research concept. Additional detail on proposed studies is included in the draft research concept documents.

Note on Accessibility: Persons with disabilities or using assistive technology may find some documents are not fully accessible. For assistance, contact Central Data Management or call 919-541-3419 and identify the documents/pages for which access is required. We will assist you in accessing the content of these files. NIEHS has helpful information on accessibility.

NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.