National Toxicology Program

National Toxicology Program

Testing Status of 2,4- & 2,6-Toluene diisocyanate - 10638-W


CASRN: 26471-62-5

Formula: C9-H6-N2-O2

Synonyms/Common Names

  • 1,3-Diisocyanatomethyl benzene (9CI)
  • Isocyanic acid, methyl-M-phenylene ester
  • TDI

Known Uses

Manufacture of flexible polyurethane foams and coatings for lacquer and wood finishes

Chemical Properties

Toxicity Effects (HSDB)

Short-Term Toxicity

  • 14-Day (Gavage)  (C50533)  Completed 
    • Rats: F344/N; Mice: B6C3F1
  • 13-Week (Gavage)  (C50533)  Completed 
    • Rats: F344/N; Mice: B6C3F1
    • Dose: 0,.15,240 MG/KG/10 PER GROUP.

Long-Term Carcinogenicity

  • 2-Year (Gavage)  (C50533)  Report Complete 
    • TR-251 (NIH Number: 86-2507)  (Peer Review Approval 09/22/1982A )
      Toxicology and Carcinogenesis Studies of Commercial Grade 2,4 (80)- and 2,6 (20)- Toluene Diisocyanate (CASRN 26471-62-5) in F344/N Rats and B6C3F1 Mice (Gavage Studies)
    • Rats: F344/N; Mice: B6C3F1
    • Carcinogenesis Results
      • Male Rats Positive 
      • Female Rats Positive 
      • Male Mice Negative 
      • Female Mice Positive 
    • Dose: MR: 0,30,60, FR&FM: 0,60,120, MM: 0,120,240, MG/KG/50 PER GROUP.

Special Studies

  • Absorption Disposition Metabolism Elimination (Gavage)  (S0057)  Completed 
    • Male Rats: F344/N
    • Dose: 60, 900 MG/KG.
  • Metabolism (Gavage)  (S0745)  Completed 
    • Citation: Dieter MP, Boorman GA, Jameson CW, Matthews HB, Huff JE. The carcinogenic activity of commercial grade toluene diisocyanate in rats and mice in relation to the metabolism of the 2,4- and 2,6-TDI isomers. Toxicol Ind Health. 1990 Dec;6(6):599-621.Pubmed Abstract
    • Male Rats: F344/N; Male and Female Mice: B6C3F1
    • Dose: Females: 60 or 120 mg/kg, Male rats 30 or 60 mg/kg, Male mice: 120 or 240 mg/kg.

Genetic Toxicology

  • Chromosome Aberrations  (544551)  Completed 
    • Mice
    •  Negative 
  • In Vitro Cytogenetics (CA/SCE)  (161856)  Completed 
    • Citation: Gulati, D., Witt, K., Anderson, B., Zeiger, E.,and Shelby, M. Chromosome aberration and sister chromatid exchange test in Chinese hamster ovary cells in vitro III: Results with 27 chemicals Environ. Molec. Mutagen. Vol. 13 (1989) 133-193
    • Sister Chromatid Exchange Weakly Positive 
    • Chromosome Aberrations Negative 
  • Drosophila  (892839)  Completed 
    • Citation: Foureman, P., Mason, J.M., Valencia, R., Zimmering, S. Chemical Mutagenesis Testing in Drosophila. X. Results of 70 coded compounds tested for the National Toxicology Program. Environ. Molec. Mutagen. Vol. 23 (1994) 208-227
    • Sex-Linked Recessive Lethal Positive 
    • Reciprocal Translocation Positive 
  • Salmonella  (654636)  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.
    •  Positive 
  • Sister Chromatid Exchanges  (544551)  Completed 
    • Mice
    • Sister Chromatid  Positive (Nonstandard Protocol) 
NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.