Ethylbenzene is a colorless flammable liquid that comes from coal tar and petroleum. It is primarily used to synthesize chemicals that are used in plastics. Ethylbenzene can also be used in fuels and injection fluid, which is used to release natural gas from the ground. It has industrial uses in solvents and pesticides and can also be found in consumer products like paint and ink. Spills and waste disposal from factories that use ethylbenzene often enter the water and soil. Burning oil, gas, coal, and cigarettes can release ethylbenzene into the air. Inhalation of this contaminated air is the primary path of exposure.

Brief inhalation of air contaminated with ethylbenzene can cause eye and throat irritation and dizziness. Little else is known about the human health effects of short- or long-term exposure to the chemical. In scientific studies of laboratory animals, short-term exposure has been shown to cause permanent hearing loss; long-term exposure has been shown to cause kidney damage too.

The International Agency for Research on Cancer says that ethylbenzene is a possible human carcinogen, meaning it might cause cancer in humans. While more studies could be done to better understand the effects of exposure on humans, it is clear ethylbenzene is a biologically dangerous chemical, and there should be protections in place to ensure that people are not exposed to it.