https://ntp.niehs.nih.gov/go/6243

Target Organs and Levels of Evidence for TR-466

Toxicology and Carcinogenesis Studies of Ethylbenzene (CASRN 100-41-4) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)

Chemical (Study Title)
CASRN		 Peer Review Date Route/Exposure Levels Study Laboratory
Ethylbenzene
100-41-4		 12/11/1996 Inhalation
R&M: 0, 75, 250, OR 750 PPM (50/SEX/SPECIES/GROUP)		 IIT Research Institute

Levels of Evidence

Male Rats: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Kidney Tubular Cell: (SINGLE SECTIONS) ADENOMA 0/50 3/50 2/50 4/50 OR CARCINOMA 0/50 0/50 1/50 3/50 COMBINED 0/50 3/50 3/50 7/50; (SINGLE AND STEP SECTIONS) ADENOMA 3/50 5/50 7/50 20/50 OR CARCINOMA 0/50 0/50 1/50 3/50 COMBINED 3/50 5/50 8/50 21/50
  • Testis: ADENOMA 36/50 33/50 40/50 44/50
Non-Neoplastic Lesions
  • KIDNEY: INCREASED SEVERITY OF NEPHROPATHY; RENAL TUBULE HYPERPLASIA
Female Rats: Some Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Kidney Tubular Cell: (SINGLE SECTIONS) ADENOMA 0/50 0/50 0/50 1/49 (SINGLE AND STEP SECTIONS) ADENOMA 0/50 0/50 1/50 8/49
Non-Neoplastic Lesions
  • KIDNEY: INCREASED SEVERITY OF NEPHROPATHY; RENAL TUBULE HYPERPLASIA
Male Mice: Some Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 5/50 9/50 10/50 16/50 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 2/50 1/50 5/50 3/50 COMBINED 7/50 10/50 15/50 19/50
Non-Neoplastic Lesions
  • LUNG: ALVEOLAR EPITHELIAL METAPLASIA
  • LIVER: SYNCYTIAL ALTERATION; HYPERTROPHY; NECROSIS
  • THYROID GLAND: FOLLICULAR CELL HYPERPLASIA
Female Mice: Some Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Liver: ADENOMA 6/50 9/50 12/50 16/50 OR CARCINOMA 7/50 4/50 3/50 12/50 COMBINED 13/50 12/50 15/50 25/50
Non-Neoplastic Lesions
  • LIVER: EOSINOPHILIC FOCUS
  • PITUITARY GLAND: HYPERPLASIA
  • THYROID GLAND: FOLLICULAR CELL HYPERPLASIA