Nominations in Review 2007

http://ntp.niehs.nih.gov/go/29287

Substances Recommended for Study:

Aminopyridines
- 2-Aminopyridine
- 3-Aminopyridine
- 4-Aminopyridine
Artificial butter flavoring mixture and certain components
- Acetoin
- Diacetyl
Asbestos, naturally occurring and atypical forms
Diethyl phthalate
2',2'''-Dithiobisbenzanilide
2-Methoxy-4-nitroaniline
Nanoscale materials
- Nanoscale gold
- Nanoscale silver
o-Phthalaldehyde

Substances for Which No Study is Recommended at this Time:

Pentaethylenehexamine

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
Environmental 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 ]

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

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

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

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)

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

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

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

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

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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