Benzene

Background

Benzene is a liquid chemical at room temperature. It either has no color or is light-yellow. It has a sweet smell and is very flammable.

Benzene evaporates into the air very quickly. It is heavier than air and may sink into lower areas. Benzene dissolves only a little in water and will float on top of water.

Where it is found

Benzene is formed in nature and from human activities. Natural sources include volcanoes and forest fires. It is also a natural part of crude oil, gasoline, and cigarette smoke.

Benzene is used often in the United States. It is in the top 20 produced chemicals by quantity. Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers.

It is also used to make:

• Detergents
• Drugs
• Dyes
• Some types of lubricants
• Pesticides
• Rubbers

How it works

Benzene works by causing cells not to work correctly.

For example, it can cause bone marrow not to produce enough red blood cells. This can lead to anemia. It can also hurt the immune system by changing blood levels of antibodies and causing the loss of white blood cells.

Signs and symptoms

The level of benzene poisoning depends on the amount, how someone was exposed, and for how long. It also depends on the person's age and medical conditions they may have.

These signs and symptoms may show up within minutes to several hours. Showing these signs and symptoms does not necessarily mean that a person has been exposed to benzene.

If breathed in:

• Drowsiness and dizziness
• Fast or irregular heartbeat
• Headaches
• Tremors
• Confusion
• Unconsciousness
• Death (at very high levels)

If swallowed:

• Vomiting or irritation of the stomach
• Dizziness
• Sleepiness
• Convulsions (uncontrolled muscle shaking)
• Fast or irregular heartbeat
• Death (at very high levels)

If a person vomits because they ate or drank something with benzene, the vomit could be sucked into the lungs. This can cause breathing problems and coughing.

If benzene touches the eyes, skin, or lungs, it can cause injury and irritation.

Exposure

People working in jobs that make or use benzene may be exposed to the highest levels of it.

Outdoors

Low levels of benzene can be found at:

• Tobacco smoke
• Gas stations
• Car exhaust
• Industrial emissions

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.

Indoors

Indoor air generally contains levels of benzene higher than those in outdoor air. It can come from products such as:

• Glues
• Paints
• Furniture wax
• Detergents

What to do if you are exposed

Get fresh air by leaving the area where the benzene is. Moving to an area with fresh air is a good way to reduce the possibility of death from benzene.

If benzene was released outside, move away from the area. If benzene was released indoors, get out of the building.

Take off your clothes

Remove the clothing as quickly as possible. Cut clothes off instead of pulling it over the head. If you are helping others, do not touch unsafe areas.

Wash your body

Wash any benzene from your skin with lots of soap and water. Washing with soap and water will protect you from any chemicals on your body.

If your eyes are burning or your vision is blurred, rinse your eyes with plain water for 10 to 15 minutes.

If you wear contacts, remove them and put them with the dirty clothing. Do not put the contacts back in your eyes (even if they are not disposable contacts).

If you wear eyeglasses, wash them with soap and water. You can put your eyeglasses back on after you wash them.

Throw your clothes away

After you have washed yourself, place your clothing inside a plastic bag. Do not touch unsafe areas of the clothing. If you have to touch unsafe areas, or you aren't sure where the unsafe areas are, wear rubber gloves. You can also use tongs, tool handles, sticks, or similar objects to put the clothing in the bag.

Anything that touches the dirty clothing should also be placed in the bag. If you wear contacts, put them in the plastic bag, too.

Tie the bag, and then put that bag inside another plastic bag. Throwing away your clothes this way helps protect you and others from any chemicals that might be on your clothes.

When the local or state health department or emergency team arrive, tell them what you did with your clothes. The health department or emergency team will arrange for further disposal. Do not handle the plastic bags yourself.

For more information about cleaning your body and throwing away your clothes after a chemical exposure, visit "About Getting Clean."

Evacuate or "shelter in place"

If you are near a benzene release, emergency teams may tell you to evacuate the area or "shelter in place" inside.

For more information on evacuation during a chemical emergency, visit "Responding to Evacuation."

For more information on sheltering in place during a chemical emergency, visit "Responding to Sheltering in Place."

Treatment

The most important thing is for people to seek medical treatment as soon as possible.

No cure exists for benzene poisoning. Benzene poisoning is treated with supportive medical care in a hospital.

Long-term health effects

Blood

Long-term exposure, or exposure of a year or more, to benzene can affect the blood. Benzene causes harmful effects on bone marrow and can cause a decrease in red blood cells, leading to anemia. It can also cause excessive bleeding and affect the immune system, increasing the chance for infection.

Bones

Studies in animals show low birth weights, bones being formed late, and bone marrow damage when pregnant animals breathed benzene.

Cancer

The Department of Health and Human Services (DHHS) has said that benzene causes cancer in humans. Long-term exposure to high levels of benzene in the air can cause leukemia, a blood-related cancer.

Fertility

Some women who breathed high levels of benzene for many months had irregular menstrual periods. Some women also had 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.

More information

Pocket Guide to Chemical Hazards

You can also contact one of the following:

• Regional poison control center: 1-800-222-1222
• Centers for Disease Control and Prevention
  • Public Response Hotline (CDC): 800-CDC-INFO
  • Teletypewriter (TTY): 888-232-6348
  • E-mail inquiries: cdcinfo@cdc.gov