National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/9576

Target Organs and Levels of Evidence for TR-313

Toxicology and Carcinogenesis Studies of Mirex (1,1a,2,2,3,3a,4,5,5,5a,5b,6-Dodecachlorooctahydro-1,3,4-metheno-1H-cyclobuta[cd]pentalene) (CASRN 2385-85-5) in F344/N Rats (Feed Studies)

Chemical (Study Title)
CASRN
Peer Review Date Primary Uses Route/Exposure Levels Study Laboratory
Mirex
2385-85-5
03/04/1987 Pesticide, fire retardant. 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. Dosed-Feed
MR&FR:0,0.1,1,10,25, 50 (2nd Study) FR:0, 50,100 ppm/52 per group
Frederick Cancer Research Facility

Levels of Evidence

Male Rats: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Liver: neoplastic nodule 3/52 5/52 5/52 14/52 15/52 26/52
  • Adrenal Gland Medulla: pheochromocytoma 8/51 7/52 13/52 11/52 18/51 19/51
  • Kidney Transitional Cell: papilloma 0/51 0/51 0/52 0/52 1/51 3/52
Non-Neoplastic Lesions
  • Liver: cytomegaly; fatty metamorphosis; angiectasis; necrosis
Female Rats: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Liver: neoplastic nodule 2/52 23/52 30/52
  • Hematopoietic System: leukemia 6/52 9/52 14/52
Non-Neoplastic Lesions
  • Liver: cytomegaly; Fatty metamorphosis; necrosis


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