Current Nominations in Review

http://ntp.niehs.nih.gov/go/33220

Bisphenol AF
Dimethylamine borane
Ethylene glycol 2-ethylhexyl ether
Hydroxyurea
L-beta-Methylaminoalanine

Triclosan

Substances studied by the NTP are selected primarily on the basis of known or anticipated human exposure, production levels, suspicion of toxicity based on chemical structure or existing health effects data, availability of toxicological data, and extent of public concern. Selection of a substance for study does not imply that the substance is hazardous or a potential carcinogen in laboratory animals; likewise, when substances are not selected for toxicological evaluation by the Program, this should not be taken to mean that the substance is not potentially hazardous or potentially carcinogenic in laboratory animals. Nominated substances in the table below are identified by a common or generic name and CAS Registry No. where appropriate.

* Note: The terms "initial toxicological characterization" and "comprehensive toxicological characterization" in this table refer to the approximate scope of a research program to address toxicological data needs. The types of toxicological studies that would be considered by NTP staff during the conceptualization and design of a research program for each are:

Initial toxicological characterization: biomolecular screening, in vitro mechanistic, in vitro and in vivo genotoxicity, absorption, disposition, metabolism, and elimination, and short-term repeat dose (2-4 weeks) in vivo studies
Comprehensive toxicological characterization: all of the aforementioned plus subchronic toxicity (13-26 weeks), chronic toxicity (1-2 years), carcinogenicity in conventional or genetically modified rodent models, organ systems toxicity (immunotoxicity, reproductive and developmental toxicity, neurotoxicity), in vivo mechanistic, toxicokinetics, and other special studies as appropriate (e.g. chemistry, toxicogenomics, phototoxicity).

See here for further Description of NTP Study Types.

For information, questions or comments, contact:
Dr. Scott A. Masten
Director, Office of Nomination and Selection
National Toxicology Program
National Institute of Environmental Health Sciences

P.O. Box 12233, MD EC-31
Research Triangle Park, NC
(919) 541-5710 (voice)
(919) 541-3647 (fax)

[ Send Email ]

Bisphenol AF
Substance [CAS No.]	Nominated by	Nomination Rationale (Principles)	Preliminary Study Recommendations
Bisphenol AF [1478-61-1]	National Institute of Environmental Health Sciences	Moderate production and use in polymer synthesis; short-term studies suggest potential for endocrine disruption and adverse reproductive effects; lack of adequate toxicity data	Comprehensive toxicological characterization

Dimethylamine borane
Substance [CAS No.]	Nominated by	Nomination Rationale (Principles)	Preliminary Study Recommendations
Dimethylamine borane [74-94-2]	National Institute for Occupational Safety and Health	Possible contact sensitizer and systemic toxicant but insufficient evidence as determined by the NIOSH Dermal Subject Matter Expert Workgroup	Dermal absorption studies Skin sensitization studies Subchronic dermal toxicity studies with neurotoxicity and behavioral assessments

Ethylene glycol 2-ethylhexyl ether
Substance [CAS No.]	Nominated by	Nomination Rationale (Principles)	Preliminary Study Recommendations
Ethylene glycol 2-ethylhexyl ether [1559-35-9]	National Institute of Environmental Health Sciences	High production volume; potential worker exposures; suspicion of toxicity based on chemical structure; lack of adequate toxicity data	Reproductive and developmental toxicity studies

Hydroxyurea
Substance [CAS No.]	Nominated by	Nomination Rationale (Principles)	Preliminary Study Recommendations
Hydroxyurea [127-07-1] NTP Center for the Evaluation of Risks to Human Reproduction (CERHR) Evaluation NIH State-of-the-Science Conference (February 25-27, 2008: Hydroxyurea Treatment for Sickle Cell Disease	National Institute of Environmental Health Sciences 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	No experimental animal toxicity studies at this time; human studies currently being considered by the NIH and other federal agencies may address outstanding safety concerns

L-beta-Methylaminoalanine
Substance [CAS No.]	Nominated by	Nomination Rationale (Principles)	Preliminary Study Recommendations
L-beta-Methylaminoalanine [15920-93-1]	National Institute of Environmental Health Sciences	Natural product of cyanobacteria with localized and potentially widespread environmental occurrence; suspected risk factor for neurological disease(s); lack of adequate toxicity data	Absorption, distribution, metabolism, and elimination studies Neurotoxicity studies Biomolecular screening studies

Triclosan
Substance [CAS No.]	Nominated by	Nomination Rationale (Principles)	Preliminary Study Recommendations
Triclosan [3380-34-5]	Private Individual U.S. Food and Drug Administration	Widespread use in consumer products; frequent and long-term exposure for all age groups; lack of adequate toxicity data for dermal exposures	Carcinogenicity studies via dermal administration Phototoxicity studies Reproductive toxicity studies

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Web page last updated on October 21, 2008