National Toxicology Program

National Toxicology Program

Testing Status of Chloroprene - 10573-D


CASRN: 126-99-8

Formula: C4-H5-Cl

Synonyms/Common Names

  • 2-Chlor-1,3-butadiene

Known Uses

Monomer for neoprene elastomers. Industrial rubber products. Component of adhesives in food packaging.

Chemical Properties

Toxicity Effects (HSDB)

Short-Term Toxicity

  • 2 weeks (Inhalation)  (C50522)  Completed 
    • Rats: F344/N; Mice: B6C3F1
  • 26 weeks (Inhalation)  (C50522C)  Completed 
    • Mice: P53 +/- (C57BL/6)
    • Dose: FM: 0, 2.0, 12.8, or 80 ppm; 20/dose.
  • 26 weeks (Inhalation)  (C50522D)  Completed 
    • Mice: FVB/N; Mice: Tg.AC (FVB/N) Hemizygous; Mice: Tg.Lac1/C57BL/6 (Big Blue)
    • Dose: FM: 0, 2.0, 12.8, or 80 ppm; 20/strain/dose.
  • 13 weeks (Inhalation)  (C50522)  Completed 
    • Rats: F344/N; Mice: B6C3F1
    • Dose: R:0,32,80,200,500PPM M:0,12,32,80,200PPM.

Long-Term Carcinogenicity

  • 2 years (Inhalation)  (C50522B)  Report Complete 
    • TR-467 (NIH Number: 98-3957)  (Peer Review Approval 12/11/1996A )
      Toxicology and Carcinogenesis Studies of Chloroprene (CASRN 126-99-8) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)
    • Rats: F344/N; Mice: B6C3F1
    • Carcinogenesis Results
      • Male Rats Clear Evidence 
      • Female Rats Clear Evidence 
      • Male Mice Clear Evidence 
      • Female Mice Clear Evidence 
    • Dose: R&M: 0, 12.8, 32.0, or 80.0 ppm; 50/sex/species/group.

Genetic Toxicology

  • Chromosome Aberrations  (A84892)  Completed 
    • Mice
    •  Negative 
  • Drosophila  (433265)  Completed 
    • Citation: Foureman, P., Mason, J.M., Valencia, R., Zimmering, S. Chemical Mutagenesis Testing in Drosophila. X. Results of 70 coded compounds tested for the National Toxicology Program. Environ. Molec. Mutagen. Vol. 23 (1994) 208-227
    • Reciprocal Translocation/Sex-Linked Recessive Lethal Negative 
  • Micronucleus  (A18069)  Completed 
    • Mice: Tg.AC (FVB/N) Hemizygous
    • Female Negative 
  • Micronucleus  (A73731)  Completed 
    • Mice: MICE
    • Female Negative 
  • Micronucleus  (A74378)  Completed 
    • Mice: B6C3F1
    • Male Negative (Nonstandard Protocol) 
  • Micronucleus  (A75483)  Completed 
    • Mice: MICE
    • Female Negative 
  • Micronucleus  (A84892)  Completed 
    • Micronucleus  (A84893)  Completed 
      • Citation: Tice, R.R., Boucher, R., Luke, C.A., Paquette, D.F., Melnick, R.L., and Shelby, M.D. Chloroprene and isoprene: Cytogenetic studies in mice. Mutagenesis. Vol. 3 (1988) 141-146
      • 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 Negative 
      • Female Negative 
    • Salmonella  (703184)  Completed 
      • Citation: Zeiger E, Anderson B, Haworth S, Lawlor T, Mortelmans K, Speck W. Salmonella mutagenicity tests: III. Results from the testing of 255 chemicals. Environ Mutagen. 1987;9 Suppl 9:1-109.
      •  Negative 
    • Sister Chromatid Exchanges  (A74378)  Completed 
      • Mice
      • Sister Chromatid  Negative (Nonstandard Protocol) 
    • Sister Chromatid Exchanges  (A84892)  Completed 
      • Mice

    Organ Systems Toxicity

    • Neurotoxicology Assessment (Inhalation)  (NTA94018)  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 Rats: F344/N
    • Conventional Teratology (Inhalation)  (TER91042)  Completed 
      • Citation: Inhalation Developmental Toxicology Studies: Developmental Toxicity of Chloroprene Vapors in New Zealand White Rabbits (April 1994)
      • Female Rabbit: New Zealand White
      • Rabbits Maternal Negative 
      • Rabbits Fetal Negative 
    NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.