National Toxicology Program

National Toxicology Program
http://ntp.niehs.nih.gov/go/34900

Nominations in Review 2009 (Fall)

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).

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)

[Send Email]

Back to top

Butterbur
Substance
[CAS No.]
Nomination Source Nomination Rationale
(Principles)
Preliminary Study Recommendations
Butterbur (Petasites hybridus) extract (760 KB)
[90082-63-6]
NIEHS Use as a dietary supplement; lack of toxicological data; suspicion of toxicity based on pharmacological activity of constituents; potential presence of toxic pyrrolizidine alkaloids Comprehensive toxicological characterization

Back to top

Evening primrose oil
Substance
[CAS No.]
Nomination Source Nomination Rationale
(Principles)
Preliminary Study Recommendations
Evening primrose oil (Oenothera biennis L.) extract (532 KB)
[90028-66-3]
NIEHS Use as a dietary supplement, particularly for immune conditions; lack of adequate toxicological data -Initial toxicological characterization
-Immunotoxicity studies
-Reproductive toxicity studies

Back to top

Hydroquinone
Substance
[CAS No.]
Nomination Source Nomination Rationale
(Principles)
Preliminary Study Recommendations
Hydroquinone (452 KB)
[123-31-9]
U.S. Food and Drug Administration Use in drugs and cosmetics; evidence of carcinogenicity from oral exposures in prior NTP studies; insufficient toxicological data for regulatory hazard determination -Dermal toxicity and carcinogenicity studies
-Reproductive toxicity studies

Back to top

Silica flour
Substance
[CAS No.]
Nomination Source Nomination Rationale
(Principles)
Preliminary Study Recommendations
Silica flour (700 KB)
[14808-60-7]
Private Individual Use in industrial and consumer products; inhalation exposures associated with autoimmune disease; lack of toxicity data for oral and dermal exposures; insufficient data to evaluate dose-response for renal and autoimmune effects by any route of exposure -Initial toxicological characterization via oral and dermal routes of administration
-Immunotoxicity studies

Back to top

Valerian root extract and oil
Substance
[CAS No.]
Nomination Source Nomination Rationale
(Principles)
Preliminary Study Recommendations
Valerian (Valeriana officinalis L.) root extract (1.5 MB)
[8057-49-6]
Valerian oil (1.5 MB)
[8008-88-6]
NIEHS Use as a dietary supplement; lack of toxicological data; concern for adverse developmental and reproductive effects Comprehensive toxicological characterization


Note: Some documents on this page are provided in PDF (Portable Document Format) and may not be fully accessible to some readers. If you have difficulty accessing a document, please send email to the NTP Webmaster [ Send Email ] or call Dr. Scott Masten 919-541-5710 and identify documents/pages for which access is required.

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