National Toxicology Program

CASRN: 126-99-8

Formula: C4-H5-CL

Synonyms/Common Names:

• 2-CHLORO-1,3-BUTADIENE

Known Uses:

MONOMER FOR NEOPRENE ELASTOMERS. INDUSTRIAL RUBBER PRODUCTS. COMPONENT OF ADHESIVES IN FOOD PACKAGING. (TDB)

Short-Term Toxicity

• 2-WEEK (Inhalation)  (C50522) Completed 
  • NTIS No. PB99-123671
    Citation: Toxicology and Carcinogenesis Studies of Chloroprene (CAS No. 126-99-8) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)
  • Rats: F344/N; Mice: B6C3F1
• 26-WEEK (Inhalation)  (C50522C) Completed 
  • Mice: P53 +/- (C57BL/6)
  • Dose: FM: 0, 2.0, 12.8, OR 80 PPM; 20/DOSE
• 26-WEEK (Inhalation)  (C50522D) Completed 
  • Mice: Tg.AC (FVB/N) Hemizygous; Mice: FVB/N; Mice: Tg.Lac1/C57BL/6 (Big Blue)
  • Dose: FM: 0, 2.0, 12.8, OR 80 PPM; 20/STRAIN/DOSE
• 13-WEEK (Inhalation)  (C50522) Completed 
  • NTIS No. PB99-123671
    Citation: Toxicology and Carcinogenesis Studies of Chloroprene (CAS No. 126-99-8) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Dose: R:0,32,80,200,500PPM M:0,12,32,80,200PPM

Long-Term Carcinogenicity

• 2-YEAR (Inhalation)  (C50522B) Report Complete 
  • TR-467 (NTIS No. PB99-123671)  (Peer Review 12/11/1996)
    Toxicology and Carcinogenesis Studies of Chloroprene (CAS No. 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
  • Chromosome Aberation  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: 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
  • 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
  • Mice: B6C3F1
  • Male Negative 
  • Female Negative 
• Salmonella  (703184) Completed 
  • Citation: Zeiger, E., Anderson, B., Haworth, S., Lawlor, T., Mortelmans, K., and Speck, W. Salmonella mutagenicity tests. III. Results from the testing of 225 chemicals Environ. Mutagen. Vol. 9 (Suppl 9) (1987) 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).
  • M Rats: F344/N
• Conventional Teratology (Inhalation)  (TER91042) Completed 
  • Citation: DE94-012384
  • F Rabbit: New Zealand White
  • Rabbits Maternal Negative 
  • Rabbits Fetal Negative 
  • Dose: 0, 10, 40, 175 PPM