National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/1123

Nominations Reviewed in 2005

Chemicals studied by the NTP are selected mainly on the basis of human exposure, production levels, chemical structure, and available toxicological data. Selection of an agent for a study does not imply that the agent is hazardous or a potential carcinogen in laboratory animals; likewise, an agent not selected for toxicologic study by the Program should not be taken to mean that the agent is not potentially hazardous or potentially carcinogenic in laboratory rodents. Substances are identified by a common or generic name and CAS Registry No. where appropriate.

Note: A recommendation for "toxicological characterization" in this table includes studies for genotoxicity, subchronic toxicity, and chronic toxicity/carcinogenicity, as determined to be appropriate during the conceptualization and design of a research program to address toxicological data needs. Though other types of studies (e.g. metabolism and disposition, immunotoxicity, reproductive/developmental toxicity) may be conducted as part of a complete toxicological characterization, these types of studies are not listed unless they were specifically recommended.

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]

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Acetyl-L-carnitine hydrochloride and Α-Lipoic acid
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Acetyl-L-carnitine hydrochloride and Α-Lipoic acid
[5080-50-2],[62-46-4]
National Cancer Institute Consumer exposure through increasing dietary supplement use; lack of adequate toxicological data Subchronic toxicity studies (individual and combination studies)

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Antimony trioxide
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Antimony trioxide
[1309-64-4]
National Institute of Environmental Health Sciences Significant human exposure in occupational settings and lack of adequate two-year exposure carcinogenicity studies
  • Chronic toxicity and carcinogenicity studies
  • Cardiotoxicity studies

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Butylparaben
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Butylparaben
[94-26-8]
National Institute of Environmental Health Sciences Widespread use in foods, cosmetics, and pharmaceuticals; potential reproductive toxicant; lack of adequate toxicological data Toxicological characterization including reproductive toxicity studies

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1,3-Dichloropropanol
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
1,3-Dichloropropanol
[96-23-1]
National Institute of Environmental Health Sciences High production volume and use; occurrence in foods; reproductive toxicity and carcinogenicity demonstrated but not adequately characterized
  • Toxicological characterization
  • Metabolism and disposition studies
  • Reproductive toxicity studies
  • Carcinogenicity studies
  • Coordinate studies with voluntary data development activities of the U.S. Environmental Protection Agency

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2,5-Dimercapto-1,3,4-thiadiazole
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
2,5-Dimercapto-1,3,4-thiadiazole
[1072-71-5]
Chemonics Industries, Inc. Component of wildland fire retardant formulations; moderate production and industrial use; lack of adequate toxicological data
  • Genotoxicity studies
  • Metabolism and disposition studies
  • Subchronic toxicity studies

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3-Dimethylaminopropylamine
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
3-Dimethylaminopropylamine
[109-55-7]
National Cancer Institute Significant and increasing use in personal care products; widespread industrial use; lack of information on chronic toxicity; evidence of toxicity in exposed workers
  • In vitro genotoxicity studies (in combination with a nitrosating agent)
  • Dermal absorption and metabolism studies with focus on nitrosamine formation

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Gum guggul extract
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Gum guggul extract
[No CAS No.]
National Institute of Environmental Health Sciences Consumer exposure through increasing dietary supplement use; demonstrated metabolic and hormonal effects; lack of adequate toxicological data Toxicological characterization

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Imidazolidinyl urea
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Imidazolidinyl urea
[39236-46-9]
National Cancer Institute Widely used preservative in personal care products; mutagenic potential; lack of adequate carcinogenicity data
  • Genotoxicity studies
  • Dermal absorption studies
  • Evaluation of potential degradation products (e.g., diazolidinyl urea and formaldehyde)

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Permanent makeup inks
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Permanent makeup inks
[No CAS No.]
U.S. Food and Drug Administration Rapidly growing practice in the United States; lack of adequate toxicological data; numerous human adverse event reports For representative Premier Products True Color pigments:
  • In vitro and in vivo allergenicity, photoallergenicity, and phototoxicity studies
  • Chemical characterization studies

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Usnic acid and Usnea herb
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Usnic acid and Usnea herb
[125-46-2],[No CAS No.]
U.S. Food and Drug Administration Widely used in dietary supplement and personal care products; lack of adequate toxicological data; numerous human adverse event reports
  • Toxicological characterization including genotoxicity, pharmacokinetic, and developmental and reproductive toxicity studies
  • In vitro mitochondrial toxicity studies

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Vincamine
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Vincamine
[1616-90-9]
National Cancer Institute Consumer exposure through dietary supplement use; suspicion of toxicity; lack of adequate toxicological data Integrate into current NTP research program on QT interval prolongation

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Antimony trisulfide
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Antimony trisulfide
[1345-04-6]
National Cancer Institute Significant human exposure in occupational settings and suspicion of carcinogenicity No additional studies at this time due to presumed lower workplace exposures relative to other antimony compounds

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4-Bromofluorobenzene
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
4-Bromofluorobenzene
[460-00-4]
National Institute of Environmental Health Sciences High production volume and use; lack of adequate toxicological data; suspicion of toxicity based on chemical structure Defer pending review of anticipated submissions on exposure and toxicity information to the U.S. Environmental Protection Agency and possible sponsorship in the High Production Volume Challenge Program

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2,6-Diaminopyridine
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
2,6-Diaminopyridine
[141-86-6]
National Cancer Institute Moderate production and industrial use; lack of adequate toxicological data Defer pending review of additional information on uses and potential exposure from hair dyes

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Garcinia cambogia extract
Substance
[CAS No.]
Nominated by Rationale for Nomination Study Recommendations*
Garcinia cambogia extract
[No CAS No.]
National Cancer Institute Consumer exposure through increasing dietary supplement use; lack of adequate toxicological data Defer pending further review of recently published studies
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