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https://ntp.niehs.nih.gov/go/6245

Chloroprene: Target Organs and Levels of Evidence for TR-467

Toxicology and Carcinogenesis Studies of Chloroprene (CASRN 126-99-8) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)

Chemical (Study Title)
CASRN		 Peer Review Date Route/Exposure Levels Study Laboratory
Chloroprene
126-99-8		 12/11/1996 Inhalation
R&M: 0, 12.8, 32.0, OR 80.0 PPM; 50/SEX/SPECIES/GROUP		 Battelle Northwest Laboratory

Levels of Evidence

Male Rats: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Oral Cavity: SQUAMOUS CELL PAPILLOMA 0/50 2/50 4/50 10/50 OR SQUAMOUS CELL CARCINOMA 0/50 0/50 1/50 2/50 COMBINED 0/50 2/50 5/50 12/50
  • Thyroid Gland Follicular Cell: ADENOMA 0/50 2/50 2/49 4/50 OR CARCINOMA 0/50 0/50 2/49 1/50 COMBINED 0/50 2/50 4/49 5/50
  • Lung: Alveolar/Bronchiolar Adenoma 2/50 0/50 3/49 3/50 or Alveolar/Bronchiolar Carcinoma 0/50 2/50 1/49 4/50 Combined 2/50 2/50 4/49 6/50
  • Kidney Tubular Cell: (SINGLE SECTIONS) ADENOMA 0/50 1/50 1/50 2/50 (SINGLE AND STEP SECTIONS) ADENOMA 1/50 7/50 6/50 7/50 OR CARCINOMA 0/50 2/50 0/50 1/50 COMBINED 1/50 9/50 6/50 8/50
May Have Been Related
  • Urinary Bladder: TRANSITIONAL EPITHELIUM PAPILLOMA 0/50 0/50 0/50 1/49 OR CARCINOMA 0/50 0/50 1/50 0/49
Non-Neoplastic Lesions
  • LUNG: ALVEOLAR EPITHELIUM HYPERPLASIA
  • KIDNEY: INCREASED SEVERITY OF NEPHROPATHY
  • NASAL CAVITY: (OLFACTORY EPITHELIUM) ATROPHY; FIBROSIS; HYPERPLASIA; CHRONIC INFLAMMATION; METAPLASIA; NECROSIS
Female Rats: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Oral Cavity: SQUAMOUS CELL PAPILLOMA 1/49 2/50 2/50 7/50 OR SQUAMOUS CELL CARCINOMA 0/49 1/50 3/50 4/50 COMBINED 1/49 3/50 5/50 11/50
  • Thyroid Gland Follicular Cell: ADENOMA 1/49 1/50 0/50 3/50 OR CARCINOMA 0/49 0/50 1/50 2/50 COMBINED 1/49 1/50 1/50 5/50
  • Mammary Gland: FIBROADENOMA 24/49 32/50 36/50 36/50
  • Kidney Tubular Cell: (SINGLE SECTIONS) ADENOMA 0/49 0/50 0/50 2/50 (SINGLE AND STEP SECTIONS) ADENOMA 0/49 0/50 0/50 4/50
May Have Been Related
  • Lung: Alveolar/Bronchiolar Adenoma 1/49 0/50 0/50 3/50
  • Urinary Bladder: TRANSITIONAL EPITHELIUM CARCINOMA 0/49 0/50 0/50 2/50
Non-Neoplastic Lesions
  • LUNG: ALVEOLAR EPITHELIUM HYPERPLASIA
  • KIDNEY: INCREASED SEVERITY OF NEPHROPATHY
  • NASAL CAVITY: (OLFACTORY EPITHELIUM) ATROPHY; FIBROSIS; HYPERPLASIA; CHRONIC INFLAMMATION; METAPLASIA, NECROSIS
Male Mice: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Lung: Alveolar/Bronchiolar Adenoma 8/50 18/50 22/50 28/50 or Alveolar/Bronchiolar Carcinoma 6/50 12/50 23/50 28/50 Combined 13/50 28/50 36/50 43/50
  • Vascular System (Unspecified): HEMANGIOMA 0/50 1/50 2/50 2/50 OR HEMANGIOSARCOMA 3/50 13/50 22/50 19/50 COMBINED 3/50 14/50 23/50 21/50
  • Harderian Gland: ADENOMA 2/50 5/50 8/50 10/50 OR CARCINOMA 0/50 0/50 2/50 2/50 COMBINED 2/50 5/50 10/50 12/50
  • Kidney Tubular Cell: (SINGLE SECTIONS) ADENOMA 0/50 1/49 1/50 3/50 (SINGLE AND STEP SECTIONS) ADENOMA 0/50 2/49 3/50 9/50
  • Forestomach: SQUAMOUS CELL PAPILLOMA 1/50 0/50 2/50 4/50
Non-Neoplastic Lesions
  • LUNG: BRONCHIOLE HYPERPLASIA; HISTIOCYTIC CELL INFILTRATION
  • FORESTOMACH: EPITHELIAL HYPERPLASIA
  • KIDNEY: RENAL TUBULE HYPERPLASIA
  • NASAL CAVITY: (OLFACTORY EPITHELIUM) ATROPHY; METAPLASIA; HYPERPLASIA
  • SPLEEN: HEMATOPOIETIC CELL PROLIFERATION
Female Mice: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Lung: Alveolar/Bronchiolar Adenoma 2/50 16/49 29/50 26/50 or Alveolar/Bronchiolar Carcinoma 2/50 14/49 16/50 28/50 Combined 4/50 28/49 34/50 42/50
  • Vascular System (Unspecified): HEMANGIOMA 0/50 0/50 2/50 3/50 OR HEMANGIOSARCOMA 4/50 6/50 17/50 5/50 COMBINED 4/50 6/50 18/50 8/50
  • Harderian Gland: ADENOMA 1/50 3/50 3/50 8/50 OR CARCINOMA 1/50 2/50 0/50 1/50 COMBINED 2/50 5/50 3/50 9/50
  • Mammary Gland: CARCINOMA 3/50 4/50 7/50 12/50
  • Liver: ADENOMA 17/50 19/49 11/50 16/50 OR CARCINOMA 4/50 11/49 14/50 19/50 COMBINED 20/50 26/49 20/50 30/50
  • Subcutaneous Tissue: SARCOMA 0/50 11/50 11/50 18/50
  • Mesothelium (Abdominal Cavity/Tunica Vaginalis): SARCOMA 0/50 4/50 8/50 3/50
  • Zymbal Gland: CARCINOMA 0/50 0/50 0/50 3/50
  • Forestomach: Squamous Cell Papilloma 0/50 0/50 0/50 4/50
Non-Neoplastic Lesions
  • LUNG: BRONCHIOLE HYPERPLASIA; HISTIOCYTIC CELL INFILTRATION
  • FORESTOMACH: EPITHELIAL HYPERPLASIA
  • NASAL CAVITY: (OLFACTORY EPITHELIUM) ATROPHY; METAPLASIA; HYPERPLASIA
  • SPLEEN: HEMATOPOIETIC CELL PROLIFERATION


Chemical (Study Title)
CASRN		 Peer Review Date Route/Exposure Levels Study Laboratory
Chloroprene
126-99-8		 Inhalation
R:0,32,80,200,500PPM M:0,12,32,80,200PPM		 Battelle Northwest Laboratory

Levels of Evidence: None