National Toxicology Program

National Toxicology Program

Testing Status of Methyl bromide - 10399-G


CASRN: 74-83-9

Formula: C-H3-Br

Synonyms/Common Names

  • Bromomethane (9CI)

Known Uses

Fumigant, extractant, wool degreasing, in ion. Chambers, fire-extinguishing agent, insecticide, rodenticide. 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.

Chemical Properties

Toxicity Effects (HSDB)

Short-Term Toxicity

  • 14-Day (Inhalation)  (C04148A)  Completed 
    • Mice: B6C3F1
  • 6 weeks (Inhalation)  (C04148C)  Completed 
    • Rats: F344/N; Mice: B6C3F1
  • 13-Week (Inhalation)  (C04148A)  Completed 
    • Rats: F344/N; Mice: B6C3F1

Long-Term Carcinogenicity

  • 2 years (Inhalation)  (C04148B)  Report Complete 
    • TR-385 (NIH Number: 92-2840)  (Peer Review Approval 11/19/1990A )
      Toxicology and Carcinogenesis Studies of Methyl Bromide (CASRN 74-83-9) in B6C3F1 Mice (Inhalation Studies)
    • Mice: B6C3F1
    • Carcinogenesis Results
      • Male Mice No Evidence 
      • Female Mice No Evidence 
    • Dose: MICE ONLY:0,10,33,100 PPM.

Special Studies

  • Absorption Disposition Metabolism Elimination (Gavage)  (S0165)  Completed 
    • Citation: Medinsky MA, Bond JA, Dutcher JS, Birnbaum LS. Disposition of [14C]methyl bromide in Fischer-344 rats after oral or intraperitoneal administration. Toxicology. 1984 Sep 14;32(3):187-96.Pubmed Abstract
    • Male Rats: F344/N
  • Absorption Disposition Metabolism Elimination (Inhalation)  (S0335)  Completed 
    • Citation: Bond JA, Dutcher JS, Medinsky MA, Henderson RF, Birnbaum LS. Disposition of [14C]methyl bromide in rats after inhalation. Toxicol Appl Pharmacol. 1985 Apr;78(2):259-67. Pubmed Abstract
    • Citation: Medinsky MA, Dutcher JS, Bond JA, Henderson RF, Mauderly JL, Snipes MB, Mewhinney JA, Cheng YS, Birnbaum LS. Uptake and excretion of [14C]methyl bromide as influenced by exposure concentration. Toxicol Appl Pharmacol. 1985 Apr;78(2):215-25.Pubmed Abstract
    • Male Rats: F344/N

Genetic Toxicology

  • Micronucleus  (A51339)  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  (510898)  Completed 
    •  Positive 

Organ Systems Toxicity

  • Neurotoxicology Assessment (Inhalation)  (NTA94006)  Completed 
    • Citation: Animal Neurobehavioral Test Battery in NTP Assessment In: Advances in Neurobehavioral Toxicology: Applications in Environmental & Occupational Health (Barry L. Johnson, ED.), Lewis Publishers, Inc. pp. 403-418 (1990).
    • Male and Female Rats/Mice: F344/N
  • 5 days/week for 3 weeks before breeding, or 1 to 19 GD, or 3 weeks before breeding plus 1 to 19 GD Conventional Teratology (Inhalation)  (T0021A)  Completed 
    • Citation: Teratologic Assessment of Butylene Oxide, Styrene Oxide, Methylbromide
    • Female Rats: Wistar
    • Dose: 20, 70 ppm 7 hr/day.
  • 1 to 15 GD Conventional Teratology (Inhalation)  (T0021B)  Completed 
    • Citation: Teratologic Assessment of Butylene Oxide, Styrene Oxide, Methylbromide
    • Female Rabbit: New Zealand White
    • Dose: 20 or 70 ppm, 7 hr/day.
NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.