Nominations in Review 2002

http://ntp.niehs.nih.gov/go/199

Substances Recommended for Study:

Abrasive blasting agents
5-Amino-o-cresol
tert-Butyl hydroperoxide
Chloramine-T and p-Toluenesulfonamide
Cobalt metal dust
Ephedrine alkaloid dietary supplements
Ethanone
Hexafluorosilicic acid and Sodium hexafluorosilicate
Ketamine hydrochloride
Mercury, ((o-carboxyphenyl)thio)ethyl-, sodium salt (Thimerosal)
Nitrogen trifluoride
Sodium metasilicate
Turpentine
Welding fumes

Substances for Which No Study is Recommended at this Time

Hexachloro-1,3-butadiene
Infrasound
Magnesium oxide
Methylolurea
4-Methylquinoline

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.

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

P.O. Box 12233, MD A3-07
111 T.W. Alexander Drive
Research Triangle Park, NC
(919) 541-5710 (voice)
(919) 541-3647 (fax)

[ Send Email ]

Abrasive blasting agents
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Abrasive blasting agents Coal slag Crushed glass Garnet Sand Specular hematite Steel grit	National Institute for Occupational Safety and Health Occupational Safety and Health Administration	Chronic inhalation (whole body) toxicity studies in rats with tissue burden and comprehensive pulmonary toxicological evaluations	high production volume and widespread occupational exposure lack of adequate health effects information data needed to establish safe exposure limits	Toxicological studies: Chronic inhalation toxicity in male rats Pulmonary tissue burden analysis

5-Amino-o-cresol
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
5-Amino-o-cresol [2835-95-2]	National Cancer Institute	Developmental and reproductive toxicity Carcinogenicity	widely used in permanent hair dyes some evidence of toxicity lack of carcinogenicity data	Toxicological studies: Metabolism Developmental and reproductive toxicity Carcinogenicity

tert-Butyl hydroperoxide
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
tert-Butyl hydroperoxide [75-91-2]	National Cancer Institute	Carcinogenicity	high production volume industrial chemical evidence for genotoxicity and tumor promotion activity lack of carcinogenicity data	Toxicological studies: Carcinogenicity Consider mechanistic studies related to carcinogenicity of organic peroxides as a class

Chloramine-T and p-Toluenesulfonamide
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Chloramine-T and p-Toluenesulfonamide [127-65-1],[70-55-3]	Private Individual	Toxicological characterization	investigational new animal drug for antimicrobial use in aquaculture evidence for toxicity further studies needed to establish safe residue levels	Toxicological studies: In vitro and in vivo genotoxicity Subchronic toxicity and/or carcinogenicity studies may be considered when results of genotoxicity studies are available for review

Cobalt metal dust
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Cobalt metal dust [7440-48-4]	Cobalt Development Institute International Union, United Auto Workers Occupational Safety and Health Administration	Toxicological characterization including carcinogenicity studies (inhalation)	widespread occupational exposure evidence for toxicity insufficient data to assess chronic toxicity and carcinogenic potential	Toxicological studies: Toxicological characterization including carcinogenicity and developmental toxicity (inhalation studies)

Ephedrine alkaloid dietary supplements
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Ephedrine alkaloid dietary supplements [No CAS No.]	National Cancer Institute National Institutes of Health Office of Dietary Supplements	Developmental and reproductive toxicity Cardiovascular and central nervous systems toxicity Comparative toxicological evaluation of ephedra and ephedra combination dietary supplements	widely used dietary supplement reports of adverse effects in consumers lack of adequate toxicological information for multi-component dietary supplement formulations	Toxicological studies: Developmental and reproductive toxicity Subchronic toxicity Special emphasis on assessment of potential cardiovascular and central nervous systems effects Studies should use commercial ephedra products with and without caffeine and other additives

Ethanone
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Ethanone 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)-(Iso-E Super) [54464-57-2]	Private Individual	Toxicological characterization including neurotoxicity	high production volume fragrance material widespread consumer exposure lack of toxicity data	Toxicological studies: Toxicological characterization including genotoxicity

Hexachloro-1,3-butadiene
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Hexachloro-1,3-butadiene [87-68-3]	Carcinogen Identification Committee (Advisory Body for California Environmental Protection Agency)	Carcinogenicity (at doses intermediate to those used in previous studies)	persistent industrial by-product widely dispersed in environment some evidence for carcinogenicity existing data insufficient to characterize carcinogenic hazard	No toxicological studies at this time due to: low commercial production volume insufficient evidence of significant human exposure lack of availability of adequate toxicological data

Hexafluorosilicic acid and Sodium hexafluorosilicate
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Hexafluorosilicic acid and Sodium hexafluorosilicate [16961-83-4],[16893-85-9]	Private Individuals (multiple nominations)	Chemical characterization Toxicological characterization including chronic toxicity, carcinogenicity, neurotoxicity, and toxicokinetics Mechanistic studies related to cholinesterase inhibition and lead bioavailability	primary agents used to fluoridate public drinking water systems lack of toxicity information assumed complete dissociation to free fluoride under normal conditions of use not supported by experimental evidence	Chemical characterization studies to assess chemical fate under aqueous conditions Toxicological studies may be considered when results of chemical characterization studies are available for review

Infrasound
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Infrasound [no CAS No.]	National Institute of Environmental Health Sciences	Toxicological characterization	low frequency sound ubiquitous in occupational and community settings insufficient data to address public concerns regarding potential health hazards at low exposure levels	No toxicological studies at this time due to insufficient information on human exposures in community settings and questionable utility of additional studies in available animal models/test systems Consider seeking additional expert opinion on human exposure and toxicity data needs

Ketamine hydrochloride
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Ketamine hydrochloride [1867-66-9]	U.S. Food and Drug Administration	Comprehensive neurotoxicity assessment and toxicokinetics in non-human primates	approved drug for anesthetic use in adults off-label pediatric use thought to occur causes severe lesions in developing rat brain further studies needed to assess safety of pediatric use	Toxicological studies: Comprehensive neurotoxicity assessment and toxicokinetics in developing (post-natal) non-human primates

Magnesium oxide
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Magnesium oxide [1309-48-4]	National Cancer Institute	Biological disposition Chronic inhalation toxicity	high production volume industrial chemical widespread occupational exposure lack of chronic inhalation toxicity data	No toxicological studies at this time due to adequate available toxicological data

Mercury, ((o-carboxyphenyl)thio)ethyl-, sodium salt (Thimerosal)
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Mercury ((o-carboxyphenyl)thio)ethyl-, sodium salt (Thimerosal) [54-64-8]	U.S. Food and Drug Administration	Toxicokinetics Neurodevelopmental toxicity Comparative studies with methylmercury under different dosing regimens	organomercurial preservative widely used in vaccines and other therapeutics large exposed population insufficient toxicity data	Toxicological studies: Toxicokinetics Neurodevelopmental toxicity Comparative studies with ethylmercury and methylmercury under different dosing regimens in non-human primates Coordinate with ongoing federally-sponsored research efforts

Methylolurea
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Methylolurea [1000-82-4]	National Institute of Environmental Health Sciences	Toxicological characterization	high production volume industrial chemical widespread use and potential for human exposure lack of toxicity information	No toxicological studies at this time due to inclusion in the High Production Volume Chemical Challenge Program

4-Methylquinoline
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
4-Methylquinoline [491-35-0]	Carcinogen Identification Committee (Advisory Body for California Environmental Protection Agency)	Comparative metabolism studies (with quinoline) Carcinogenicity	ubiquitous environmental contaminant some evidence for carcinogenicity existing data insufficient to characterize carcinogenic potential	No toxicological studies at this time due to low commercial production volume and insufficient evidence of significant human exposure

Nitrogen trifluoride
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Nitrogen trifluoride [7783-54-2]	National Cancer Institute	Genotoxicity Metabolism	rapidly increasing industrial demand acute toxic effects well described potential for toxicity based on oxidizing properties	Toxicological studies: Genotoxicity Metabolism

Sodium metasilicate
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Sodium metasilicate [6834-92-0]	National Institute for Occupational Safety and Health	Subchronic toxicity (inhalation) Hypersensitivity (dermal and inhalation)	widespread occupational exposure evidence for biological activity insufficient toxicity data	Toxicological studies: Subchronic toxicity (inhalation studies) Respiratory hypersensitivity

Turpentine
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Turpentine [8006-64-2]	International Union, United Auto Workers	Chronic toxicity Carcinogenicity	widespread occupational and consumer exposure reports of kidney toxicity in exposed humans insufficient chronic toxicity information	Toxicological studies: Chronic toxicity Carcinogenicity

Welding fumes
Substance [CAS No.]	Nominated by	Nominated for	Rationale for Nomination	ICCEC Recommendations
Welding fumes gas metal arc welding with stainless steel electrode gas metal arc welding with mild steel electrode manual arc welding with stainless steel electrode	National Institute for Occupational Safety and Health International Union, United Auto Workers	Acute and subchronic inhalation studies to assess neurotoxicity, immunotoxicity, and pulmonary toxicity Chronic inhalation toxicity studies with one or more welding fume types	widespread occupational exposure evidence for toxicity of mixture and components gaps in available health effects data	Toxicological studies: Acute and subchronic inhalation exposure studies to assess neurotoxicity, immunotoxicity, and pulmonary toxicity of all 3 welding fume types Chronic inhalation toxicity and carcinogenicity studies with one or more welding fume types

Web page last updated on September 11, 2008