National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/9780

Target Organs and Levels of Evidence for TR-209

Carcinogenesis Bioassay of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (CASRN 1746-01-6) in Osborne-Mendel Rats and B6C3F1 Mice (Gavage Study)

Chemical (Study Title)
CASRN
Peer Review DatePrimary UsesRoute/Exposure LevelsStudy Laboratory
2,3,7,8-Tetrachlorodibenzo-p-dioxin
1746-01-6
06/27/1980Present in certain herbicide and fungicide formulations, such as 2,4,5-T and pentachlorophenols; it has been tested for use in flameproofing polyesters & against insects and wood-destroying fungi. A contaminant created in the manufacture of agent orange. Associated with tobacco: reported either as a natural component of tobacco, pyrolysis product (in tobacco smoke), or additive for one or more types of tobacco products.Gavage
R&MM: 0,.01,.05,.5 UG/KG/WK/50 PER GROUP FM: 0,.04,.2,2.0 UG/KG/WK/50 PER GROUP
IIT Research Institute

Levels of Evidence

Male Rats: Positive
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Thyroid Gland Follicular Cell: ADENOMA 1/69 5/48 6/50 10/50
Female Rats: Positive
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Liver: NEOPLASTIC NODULE 5/75 1/49 3/50 12/49
Male Mice: Positive
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Liver: CARCINOMA 8/73 9/49 8/49 17/50
Female Mice: Positive
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Liver: CARCINOMA 1/73 2/50 2/48 6/47
  • Thyroid Gland Follicular Cell: ADENOMA 0/69 3/50 1/47 5/46


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