National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/606

Nominations in Review 2002

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
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

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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)

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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

Back to top

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