Skip to Main Navigation
Skip to Page Content
COVID-19 is an emerging, rapidly evolving situation.

Get the latest public health information from CDC and research information from NIH.

U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Share This:
https://ntp.niehs.nih.gov/go/8674

Isobutyl nitrite: Target Organs and Levels of Evidence for TR-448

Toxicology and Carcinogenesis Studies of Isobutyl Nitrite (CASRN 542-56-3) in F344 Rats and B6C3F1 Mice (Inhalation Studies)

Chemical (Study Title)
CASRN		Peer Review DateRoute/Exposure LevelsStudy Laboratory
Isobutyl nitrite
542-56-3		11/29/1994Inhalation
R&M: 0, 37, 75, OR 150 PPM		IIT Research Institute

Levels of Evidence

Male Rats: Clear Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 0/46 3/46 12/46 13/46 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 1/46 2/46 1/46 6/46 COMBINED 1/46 5/46 13/46 15/46
Non-Neoplastic Lesions
  • LUNG: ALVEOLAR EPITHELIAL HYPERPLASIA
Other Considerations
  • HEMATOPOIETIC SYSTEM: MONONUCLEAR CELL LEUKEMIA 27/46 2/46 1/46 1/46
Female Rats: Clear Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 0/46 2/45 2/46 10/46 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 0/46 1/45 0/46 1/46 COMBINED 0/46 3/45 2/46 11/46
Non-Neoplastic Lesions
  • LUNG: ALVEOLAR EPITHELIAL HYPERPLASIA
Other Considerations
  • HEMATOPOIETIC SYSTEM: MONONUCLEAR CELL LEUKEMIA 14/46 1/45 0/46 1/46
Male Mice: Some Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 7/50 12/50 13/49 17/53 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 1/50 6/50 5/49 4/53 COMBINED 8/50 16/50 16/49 19/53
May Have Been Related
  • Thyroid Gland Follicular Cell: ADENOMA 1/50 0/50 0/50 5/53
Non-Neoplastic Lesions
  • LUNG: ALVEOLAR EPITHELIAL HYPERPLASIA
  • THYROID GLAND: FOLLICULAR CELL HYPERPLASIA
  • SPLEEN: HEMOSIDERIN PIGMENTATION
Female Mice: Some Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 4/51 14/51 7/50 17/50 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 2/51 2/51 2/50 2/50 COMBINED 6/51 15/51 9/50 19/50
Non-Neoplastic Lesions
  • LUNG: ALVEOLAR EPITHELIAL HYPERPLASIA
  • NASAL CAVITY: SEROUS EXUDATE; OLFACTORY EPITHELIAL ATROPHY