National Toxicology Program

CASRN: 542-56-3

Formula: C4-H9-N-O2

Synonyms/Common Names:

• ISOBUTYL NITRITE (AIDS)
• NITROUS ACID, 2-METHYLPROPYL ESTER (9CI)

Known Uses:

INDUSTRIAL INTERMEDIATE IN CHEMICAL SYNTHESIS. (TDB)

Short-Term Toxicity

• 2-WEEK (Inhalation)  (C61052B) Completed 
  • NTIS No. PB97-120232  (Peer Review 11/29/1994)
    Citation: Toxicology and Carcinogenesis Studies of Isobutyl Nitrite (CAS No. 542-56-3) in F344 Rats and B6C3F1 Mice (Inhalation Studies)
  • Rats: F344/N; Mice: B6C3F1
• 13-WEEK (Inhalation)  (C61052B) Completed 
  • NTIS No. PB97-120232  (Peer Review 11/29/1994)
    Citation: Toxicology and Carcinogenesis Studies of Isobutyl Nitrite (CAS No. 542-56-3) in F344 Rats and B6C3F1 Mice (Inhalation Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Dose: R&M: 10, 25, 75, 150, OR 300 PPM; 6 HR/DAY, 5 DAY/WEEK, 10/GROUP

Long-Term Carcinogenicity

• 2-YEAR (Inhalation)  (C61052B) Report Complete 
  • TR-448 (NTIS No. PB97-120232)  (Peer Review 11/29/1994)
    Toxicology and Carcinogenesis Studies of Isobutyl Nitrite (CAS No. 542-56-3) in F344 Rats and B6C3F1 Mice (Inhalation Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Carcinogenesis Results
  • Male Rats Clear Evidence 
  • Female Rats Clear Evidence 
  • Male Mice Some Evidence 
  • Female Mice Some Evidence 
  • Dose: R&M: 0, 37, 75, OR 150 PPM

Genetic Toxicology

• In Vitro Cytogenetics (CA/SCE)  (016060) Completed 
  • Chromosome Aberation Positive 
  • Sister Chromatid Exchange Positive 
• In Vitro Cytogenetics (CA/SCE)  (841266) Completed 
  • Chromosome Aberation Positive 
  • Sister Chromatid Exchange Positive 
• Drosophila  (399025) Completed 
  • Citation: Woodruff, R.C., Mason, J.M., Valencia, R., and Zimmering, S. Chemical mutagenesis testing in Drosophila: V. Results of 53 coded compounds tested for the National Toxicology Program. Environ. Mutagen. Vol. 7 (1985) 677-702
  • Reciprocal Translocation/Sex-Linked Recessive Lethal Negative 
• Micronucleus  (A87798) Completed 
  • Citation: Witt, K.L., Knapton, A., Wehr, C.M., Hook, G.J., Mirsalis, J., Shelby, M.D., and MacGregor, J.T. Micronucleated Erythrocyte Frequency in Peripheral Blood of B6C3F1 Mice from Short-Term, Prechronic, and Chronic Studies of the NTP Carcinogenesis Bioassay Program. Environ. Molec. Mutagen. Vol. 36 (2000) 163-194
  • Mice: B6C3F1
  • Male Positive 
  • Female Positive 
• Salmonella  (234350) Completed 
  • Citation: Mortelmans, K., Haworth, S., Lawlor, T., Speck, W., Tainer, B., and Zeiger, E. Salmonella mutagenicity tests. II. Results from the testing of 270 chemicals Environ. Mutagen. Vol. 8 (Suppl 7) (1986) 1-119
  •  Positive 
• Salmonella  (507924) Completed 
  •  Positive 
• Salmonella  (983397) Completed 
  •  Positive