National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/29287

Nominations in Review 2007

Substances Recommended for Study:

Substances for Which No Study is Recommended at this Time:

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. Preliminary study recommendations are developed and refined by the nominator, NTP staff, and the ICCEC.

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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Aminopyridines

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
Aminopyridines:
  • 2-Aminopyridine
    [504-29-0]
  • 3-Aminopyridine
    [462-08-8]
  • 4-Aminopyridine
    [504-24-5]
National Cancer Institute Moderate production and use; acutely toxic; lack of adequate toxicological data; suspicion of toxicity and carcinogenicity based on structure (1, 3, 6, 7)
  • Toxicological characterization including chronic toxicity and carcinogenicity studies for 2-aminopyridine
  • Short-term mechanistic studies for 3- and 4-aminopyridine
  • Comparative neurotoxicity studies for 2-, 3-, and 4-aminopyridine

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Artificial butter flavoring mixture and certain components

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
Artificial butter flavoring mixture and certain components:
  • Acetoin
    [513-86-0]
  • Diacetyl
    [431-03-8]
United Food and Commercial Workers International Union Evidence of lung disease in exposed workers and respiratory toxicity in short-term animal toxicity studies (1, 5, 7)
  • Chronic toxicity and carcinogenicity studies via inhalation in rats
  • Mechanistic studies

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Asbestos, naturally occurring and atypical foms

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
Asbestos, naturally occurring and atypical forms
[1332-21-4]
National Center for Environmental Health/Agency for Toxic Substances and Disease Registry

U.S. Environmental Protection Agency
Widespread community exposure in certain geographic locales; insufficient dose-response data to characterize risk from exposure to "unregulated" asbestiform mineral fibers and naturally occurring fibrous mineral "mixtures" (1, 2, 6, 7)
  • Mineral characterization
  • In vitro durability and toxicity studie
  • Subchronic and chronic toxicity/carcinogenicity studies via inhalation
  • Studies should utilize test materials representative of minerals identified in Libby, MT and at other Naturally Occurring Asbestos (NOA) sites

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Diethyl phthalate

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
Diethyl phthalate
[84-66-2]
National Institute of Environmental Health Sciences Widespread consumer exposure through use in cosmetics and personal care products; insufficient toxicity data to assess potential reproductive hazard (1, 6, 7)
  • Multigeneration oral reproductive and developmental toxicity studies
  • Toxicokinetic studies (oral and dermal routes)

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2',2'''-Dithiobisbenzanilide

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
2',2'''-Dithiobisbenzanilide
[135-57-9]
National Cancer Institute High production volume; potential worker and consumer exposures; lack of adequate toxicological data; suspicion of toxicity based on structure (1, 6, 7)
  • Genotoxicity studies
  • Metabolism studies

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2-Methoxy-4-nitroaniline

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
2-Methoxy-4-nitroaniline
[97-52-9]
National Cancer Institute High production volume; potential worker exposures; lack of adequate toxicological data; positive mutagenicity data; strong suspicion of toxicity and carcinogenicity based on structure (1, 6, 7)
  • Toxicological characterization
  • Short-term mechanistic studies to predict carcinogenic potential

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Nanoscale Materials

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
Nanoscale materials
  • Nanoscale gold
    [7440-57-5]
  • Nanoscale silver
    [7440-22-4]
U.S. Food and Drug Administration Widespread and increasing use in drug, food and cosmetic products; lack of adequate toxicological and pharmacokinetic data; need to evaluate whether the current required tests are adequate to detect adverse biological and toxicological events (1, 6, 7)
  • Nanoscale materials characterization
  • Metabolism and pharmacokinetic studies
  • Acute, subacute and subchronic toxicity studies
  • Mechanistic studies to assess the role of size and surface coating on biological disposition and toxicity

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o-Phthalaldehyde

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
o-Phthalaldehyde
[643-79-8]
National Institute for Occupational Safety and Health Widespread and increasing use as a disinfectant in health care settings; lack of adequate and publicly available toxicological data; potential skin and respiratory sensitizer (1, 6, 7) Toxicological characterization including studies to assess dermal irritation, dermal toxicity, and sensitization and asthmagenic potential

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Pentaethylenehexamine

Substance
[CAS No.]

Nominated by

Nomination Rationale
(Principles)
 

Preliminary Study Recommendations
Pentaethylenehexamine
[4067-16-7]
 
National Cancer Institute High production volume; potential worker exposures; lack of adequate toxicological data; positive mutagenicity data (1, 6, 7) No studies at this time due to the irritant and corrosive nature of this compound
 
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