National Toxicology Program

CASRN: 100-41-4

Formula: C8-H10

Synonyms/Common Names:

• BENZENE, ETHYL- (8CI)(9CI)
• EB
• PHENYLETHANE

Known Uses:

MANUFACTURE OF SYNTHETIC RUBBER. SOLVENT. FUEL ADDITIVE. CHEMICAL INTERMEDIATE. (TDB)

Nomination Background

Short-Term Toxicity

• 13-WEEK (Inhalation)  (C56393) Report Complete 
  • TOX-10 (NTIS No. PB93-149722)  (Peer Review 11/20/1990)
    Toxicity Studies of Ethylbenzene (Cas No. 100-41-4) in F344/N Rats and B6C3F1Mice (Inhalation Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Dose: R&M:0,100,250,500,750,1000PPM

Long-Term Carcinogenicity

• 2-YEAR (Inhalation)  (C56393B) Report Complete 
  • TR-466 (NTIS No. PB99-134694)  (Peer Review 12/11/1996)
    Toxicology and Carcinogenesis Studies of Ethylbenzene (CAS No. 100-41-4) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Carcinogenesis Results
  • Male Rats Clear Evidence 
  • Female Rats Some Evidence 
  • Male Mice Some Evidence 
  • Female Mice Some Evidence 
  • Dose: R&M: 0, 75, 250, OR 750 PPM (50/SEX/SPECIES/GROUP)

Special Studies

• Toxicokinetic Study  (S0636) Completed 
  • Citation: ETHLYBENZENE CHEM 02477.
  • M/F Rats: F344/N; M/F Mice: B6C3F1

Genetic Toxicology

• In Vitro Cytogenetics (CA/SCE)  (228892) Completed 
  • Chromosome Aberation Negative 
  • Sister Chromatid Exchange Negative 
• Mouse Lymphoma  (746837) Completed 
  • Citation: McGregor, D., Brown, A., Cattanach, P., Edwards, I., McBride, D., Riach, C., and Caspary, W. Responses of the L5178Y tk+/tk- mouse lymphoma cell forward mutation assay: III. 72 coded chemicals. Environ. Molec. Mutagen. Vol. 12 (1988) 85-154
  •  Positive 
• Micronucleus  (A97698) 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 Negative 
  • Female Negative 
• Salmonella  (450636) Completed 
  • Citation: Zeiger, E., Anderson, B., Haworth, S., Lawlor, T., and Mortelman, K. Salmonella Mutagenicity Tests V. Results from the Testing of 311 Chemicals Environ. Molec. Mutagen. Vol. 19 (Suppl 21) (1992) 2-141
  •  Negative 

Organ Systems Toxicity

• 5 CONS D Dominant Lethal (Intraperitoneal Injection)  (T0048C) Completed 
  • M Rats: Sprague Dawley
  • Dose: 850 MG/KG FOR 5 CONS DAYS
• GD 1-24 Conventional Teratology (Inhalation)  (T0048A) Completed 
  • NTIS No. PB83-208074
    Citation: Teratologic Assessment of Ethylbenzene and 2-Ethoxyethanol
  • F Rabbit: New Zealand White
  • Dose: 100 OR 960 PPM
• PREGEST: 7HR/D, 5D/WK FOR 3 WKS. GEST: 7HR/D ON GD 1-19 Conventional Teratology (Inhalation)  (T0048B) Completed 
  • NTIS No. PB83-208074
    Citation: Teratologic Assessment of Ethylbenzene and 2-Ethoxyethanol
  • F Rats: Wistar
  • Dose: PREGEST: 95,960 PPM. GEST: 95,985 PPM.