What Is Benzene? | Chemical Safety Facts

Benzene

Benzene is a colorless, sweet-smelling chemical that can be derived from natural gas, crude oil, or coal.

What is benzene?

Benzene is primarily used as a feedstock, or raw material, to make other industrial chemicals, such as ethylbenzene, cumene and cyclohexane. Benzene is also used as a solvent in the chemical and pharmaceutical industries.

Most benzene exposure comes from the air from a number of sources, including forest fires, auto exhaust and gasoline from fueling stations. Benzene in cigarette smoke is a major source of exposure. Very low levels of benzene have been detected in fruits, vegetables, nuts, dairy products, eggs and fish. Most people are exposed to only very tiny amounts of benzene from water and food.

Uses & Benefits

As a building block chemical, benzene is reacted with other chemicals to produce a variety of other chemistries, materials and, ultimately, consumer goods.

Benzene is used to make other chemicals like ethylbenzene, cumene and cyclohexane, which are then reacted and used in the manufacture of a variety of materials and plastics such as polystyrene, ABS, and nylon. There can be many steps in the process that starts with the benzene molecule and ends with a completed material or consumer product. For example, benzene is a building block used to make ethylbenzene, which is then used to make styrene, which is used to make polystyrene. The end material, polystyrene, is a completely different material chemically than benzene.

For consumer products where benzene is used as a building block or intermediate, the benzene is typically fully reacted in a closed system, with little to no benzene remaining in the finished consumer product.

Benzene also is used to make some types of lubricants, rubbers, dyes, detergents, drugs, explosives and pesticides.

Benzene is naturally found in crude oil. Crude oil is refined into gasoline by using heat, pressure and chemicals in the refinery to separate the spectrum of petroleum products from crude oil. The refining process yields gasoline and a number of other petroleum products, including diesel and jet fuels, solvents, lubricating oils, many of which include small amounts of benzene.

Safety Information

The U.S. Occupational Safety and Health Administration (OSHA) monitors and regulates benzene exposure in industrial settings. OSHA has been monitoring benzene exposure and instituting rules to decrease such exposure since the 1970s. OSHA sets strict limits on exposure in industrial settings: 1 part benzene vapor per 1 million parts air for an 8 hour day. To help protect workers, businesses follow OSHA guidelines on proper ventilation for their facilities and provide employees with safety gear.

U.S. Environmental Protection Agency (EPA) guidelines set limits on the amount of benzene that can be released into the environment from industrial and commercial sources, including setting limits on the amount of benzene that can be used in gasoline. Benzene is found in emissions from power plants, primarily those using coal and oil as fuels, as well as from car exhaust.

EPA has set a maximum contaminant level (MCL) for benzene of 5 parts per billion in drinking water. FDA has adopted this same level for bottled water. Cigarette smoke accounts for about half of the U.S. national exposure to benzene.

Answering Questions

What are benzene uses?

As a building block chemical, benzene is reacted with other chemicals to produce a variety of other chemistries, materials and, ultimately, consumer goods. Benzene is used to make some types of dyes, detergents and pharmaceutical drugs, for example.

What are products with benzene?

Benzene is used to make some types of lubricants, rubbers, dyes, detergents, pharmaceutical drugs, explosives and pesticides.

Is benzene ever found in the environment?

Yes. Benzene is found naturally in the environment, and it also is emitted from industrial sources. The U.S. Environmental Protection Agency closely monitors and sets strict limits on benzene emitted from industrial sources.

Is benzene toxic or dangerous?

The seriousness of poisoning caused by benzene depends on the amount, route, and length of time of exposure, as well as the age and preexisting medical condition of the exposed person. For example, small amounts of benzene, which are not harmful, can be found in fruit, fish or vegetables, according to the U.S. National Library of Medicine. However breathing very high levels of benzene, or eating or drinking foods contaminated with high levels of benzene, can cause serious health effects or death.

You can be exposed to higher than normal levels of benzene at work if you work at a facility that makes or uses benzene, according to the U.S. National Library of Medicine. In those industrial settings, exposure to benzene can be reduced by using engineering controls and personal protective equipment.

How are people exposed to benzene?

Everyone is exposed to a small amount of benzene every day, according to the CDC. People can be exposed to low levels of benzene from tobacco smoke, automobile service stations, exhaust from motor vehicles and industrial emissions. According to the U.S. National Cancer Institute, the highest exposures to benzene have typically been in the workplace where workers produce or use benzene, although federal and state regulations have reduced these exposures in recent decades. Similarly, limits on the amount of benzene allowed in gasoline have contributed to reduced exposures.

In industrial settings, OSHA monitors and regulates benzene exposure to protect human health.

What are the health effects of benzene?

Breathing benzene can cause drowsiness, dizziness, and unconsciousness; long-term benzene exposure causes effects on the bone marrow and can cause anemia and leukemia. More information about health effects can be found on the CDC’s website.