National Toxicology Program

National Toxicology Program

Testing Status of 2-Mercaptobenzimidazole - 10264-H


CASRN: 583-39-1

Formula: C7-H6-N2-S

Synonyms/Common Names

  • 1,3-Dihydro-2H-benzimidazole-2-thione (9CI)

Known Uses

Aging inhibitors in electrical insulation.

Chemical Properties

Toxicity Effects (HSDB)

Short-Term Toxicity

  • 14-Day (Inhalation)  (C60980A)  Completed 
    • Rats: F344/N; Mice: B6C3F1
  • 2 weeks (Inhalation)  (C60980B)  Completed 
    • Rats: F344/N; Mice: B6C3F1
  • 13-Week (Inhalation)  (C60980A)  Completed 
    • Rats: F344/N; Mice: B6C3F1
    • Dose: 0, 0.1, 10 MG/M3/10 PER GROUP.
  • 13 weeks (Inhalation)  (C60980B)  Completed 
    • Rats: F344/N; Mice: B6C3F1
    • Dose: R&M: 0, 3.13, 6.25, 12.5, 25, OR 50 MG/M3.

Special Studies

  • Absorption Disposition Metabolism Elimination (Gavage; Intravenous)  (S0052)  Completed 
    • Citation: el Dareer SM, Kalin JR, Tillery KF, Hill DL. Disposition of 2-mercaptobenzimidazole in rats dosed orally or intravenously. J Toxicol Environ Health. 1984;14(4):595-604.Pubmed Abstract
    • Male Rats: F344/N
    • Dose: PO:0.5, 49 MG/KG IV: 0.5 MG/KG.

Genetic Toxicology

  • In Vitro Cytogenetics (CA/SCE)  (550909)  Completed 
    • Sister Chromatid Exchange Positive 
    • Chromosome Aberrations Positive 
  • Mouse Lymphoma  (751815)  Completed 
    • Mice
    •  Positive 
  • Micronucleus  (A06027)  Completed 
    • Citation: Witt, K.L., Knapton, A., Wehr, C.M., Hook, G.J., Mirsalis, J., Shelby, M.D., and MacGregor, J.T. Micronucleated Erythrocyte Frequency in Peripheral Blood of B6C3F1 Mice from Short-Term, Prechronic, and Chronic Studies of the NTP Carcinogenesis Bioassay Program. Environ. Molec. Mutagen. Vol. 36 (2000) 163-194
    • Mice: B6C3F1
    • Male Negative 
    • Female Negative 
  • Salmonella  (595301)  Completed 
    • Citation: Zeiger E, Anderson B, Haworth S, Lawlor T, Mortelmans K, Speck W. Salmonella mutagenicity tests: III. Results from the testing of 255 chemicals. Environ Mutagen. 1987;9 Suppl 9:1-109.
    •  Negative 
NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.