Toxicity Profiles

RAGs A Format for Ethylbenzene - CAS Number 100414

Ethylbenzene is a colorless, flammable liquid that smells like gasoline. It is found in natural products such as coal tar and petroleum and in manufactured products such as inks, insecticides, and paints. Ethylbenzene is used primarily to make another chemical, styrene. Additionally, it may be used as a solvent, in aviation fuels, and to make other chemicals. The general public can be exposed to ethylbenzene in ambient air as a result of releases from vehicle exhaust and cigarette smoke.

Ethylbenzene can be absorbed through the lungs, digestive tract, and skin. Limited information is available on the health effects of ethylbenzene on humans. The available information shows dizziness, throat and eye irritation, tightening of the chest, and a burning sensation in the eyes of humans exposed to high levels of ethylbenzene in air. Animal studies have shown effects on the nervous system, liver, kidneys, and eyes from breathing ethylbenzene in air. Ingestion of sublethal amounts of ethylbenzene is likely to cause central nervous system (CNS) depression, oro-pharyngeal and gastric discomfort, and vomiting. Animal studies indicate that the primary target organs following chronic oral exposures are likely to be the liver and kidney.

No human studies of oral or inhalation exposure to ethylbenzene have resulted in cancer. Two available animal studies suggest that ethylbenzene may cause tumors. Ethylbenzene is placed by EPA in Group D, not classifiable as to human carcinogenicity, based on a lack of data in humans and animals.

The following is a presentation of the toxicity information associated with Ethylbenzene.

Noncarcinogenic Health Effects
  • The Oral Chronic Reference Dose is 1.00E-01 (mg/kg-day).
  • The Oral Chronic Reference Dose has a modifying factor of 1.
  • The Oral Chronic Reference Dose has an uncertainty factor of 1000.
  • The Oral Chronic Reference Dose is based on the Wolf et al. study from 1956.
  • The Oral Chronic Reference Dose study target organs are liver and kidney.
  • The Oral Chronic Reference Dose study critical effect is toxicity.
  • The overall confidence in the Oral Chronic Reference Dose is low.

  • The Inhalation Chronic Reference Concentration is 1.00E+00 (mg/m3).
  • The Inhalation Chronic Reference Concentration has a modifying factor of 1.
  • The Inhalation Chronic Reference Concentration has an uncertainty factor of 300.
  • The Inhalation Chronic Reference Concentration is based on the Andrew et al. study from 1981.
  • The Inhalation Chronic Reference Concentration study critical effect is developmental toxicity.
  • The overall confidence in the Inhalation Chronic Reference Concentration is low.

  • The Dermal Chronic Reference Dose is 9.70E-02 (mg/kg-day).
  • The Dermal Chronic Reference Dose is based on a gastrointestinal absorption factor of 0.9700.

Carcinogenic Health Effects
  • The Inhalation Unit Risk is 1.1E-03 (mg/m3)-1.
  • The Inhalation Unit Risk study target organ is kidney.
  • The Inhalation Unit Risk study cancer type is tumors.
  • The Inhalation Unit Risk is based on the NTP study from 1999.