What  is benzene?

What benzene is

• Benzene is a chemical that is a colorless or light yellow liquid at room temperature. It has a sweet odor and is highly flammable.
• Benzene evaporates into the air very quickly. Its vapor is heavier than air and may sink into low-lying areas.
• Benzene dissolves only slightly in water and will float on top of water.

Where benzene is found and how it is used

• Benzene is formed from both natural processes and human activities.
• Natural sources of benzene include volcanoes and forest fires. Benzene is also a natural part of crude oil, gasoline, and cigarette smoke.
• Benzene is widely used in the United States . It ranks in the top 20 chemicals for production volume.
• Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers. Benzene is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.

How you could be exposed to benzene

• Outdoor air contains low levels of benzene from tobacco smoke, gas stations, motor vehicle exhaust, and industrial emissions.
• Indoor air generally contains levels of benzene higher than those in outdoor air. The benzene in indoor air comes from products that contain benzene such as glues, paints, furniture wax, and detergents.
• The air around hazardous waste sites or gas stations can contain higher levels of benzene than in other areas.
• Benzene leaks from underground storage tanks or from hazardous waste sites containing benzene can contaminate well water.
• People working in industries that make or use benzene may be exposed to the highest levels of it.
• A major source of benzene exposure is tobacco smoke.

How benzene works

• Benzene works by causing cells not to work correctly. For example, it can cause bone marrow not to produce enough red blood cells, which can lead to anemia. Also, it can damage the immune system by changing blood levels of antibodies and causing the loss of white blood cells.
• 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.

Immediate signs and symptoms of exposure to benzene

• People who breathe in high levels of benzene may develop the following signs and symptoms within minutes to several hours:
  • Drowsiness
  • Dizziness
  • Rapid or irregular heartbeat
  • Headaches
  • Tremors
  • Confusion
  • Unconsciousness
  • Death (at very high levels)
• Eating foods or drinking beverages containing high levels of benzene can cause the following symptoms within minutes to several hours:
  • Vomiting
  • Irritation of the stomach
  • Dizziness
  • Sleepiness
  • Convulsions
  • Rapid or irregular heartbeat
  • Death (at very high levels)
• If a person vomits because of swallowing foods or beverages containing benzene, the vomit could be sucked into the lungs and cause breathing problems and coughing.
• Direct exposure of the eyes, skin, or lungs to benzene can cause tissue injury and irritation.
• Showing these signs and symptoms does not necessarily mean that a person has been exposed to benzene.

Long-term health effects of exposure to benzene

• The major effect of benzene from long-term exposure is on the blood. (Long-term exposure means exposure of a year or more.) Benzene causes harmful effects on the bone marrow and can cause a decrease in red blood cells, leading to anemia. It can also cause excessive bleeding and can affect the immune system, increasing the chance for infection.
• Some women who breathed high levels of benzene for many months had irregular menstrual periods and a decrease in the size of their ovaries. It is not known whether benzene exposure affects the developing fetus in pregnant women or fertility in men.
• Animal studies have shown low birth weights, delayed bone formation, and bone marrow damage when pregnant animals breathed benzene.
• The Department of Health and Human Services (DHHS) has determined that benzene causes cancer in humans. Long-term exposure to high levels of benzene in the air can cause leukemia, cancer of the blood-forming organs.