Also known as: Benzol, Mineral Naphtha, Phenyl Hydride, Annulene
Chemical reference number (CAS): 71-43-2
What is benzene?
Benzene is a widely used industrial chemical. Benzene is found in crude oil and is a
major part of gasoline. Its used to make plastics, resins, synthetic fibers, rubber
lubricants, dyes, detergents, drugs and pesticides. Benzene is produced naturally by
volcanoes and forest fires.
In homes, benzene may be found in glues, adhesives, cleaning products, paint strippers,
tobacco smoke and gasoline. Most benzene in the environment comes from our use of
Benzene quickly evaporates from water or soil. If benzene leaks from buried storage
tanks or landfills, it can contaminate nearby drinking water wells. Benzene can move long
distances in groundwater.
How are people exposed to benzene?
Breathing: The most common way people are exposed to benzene is when
they fill their car with gasoline. People are also exposed to benzene when they use
household products that contain benzene.
Benzene evaporates quickly from contaminated water. People can be exposed to benzene if
they use contaminated water to bathe, shower, wash dishes or do laundry.
Benzene vapors are present in exhaust from many industries and automobiles. People who
live near highways or industries can be exposed to benzene.
Drinking/Eating: People whose drinking water wells are located within
half a mile of a leaking underground storage tank, may be exposed by drinking contaminated
Touching: Benzene can pass through the skin. Benzene exposure through
skin contact with gasoline or other solvents is possible. People can also absorb benzene
as they bathe or shower in contaminated water.
Do standards exist for regulating benzene?
Water: The state and federal drinking water standards for benzene are
both set at 5 parts per billion (ppb). We suggest you stop drinking water that contains
more than 5 ppb of benzene. If the level of benzene in your water is higher than 100 ppb,
you may also need to avoid washing, bathing or using the water for other purposes. Contact
your local public health agency for more information specific to your situation.
Air: No standards exist for regulating the amount of
benzene allowed in the air of homes. However, the Wisconsin Department
of Natural Resources (DNR) has set a residential indoor air action level for
benzene at 0.95 parts per billion by volume (ppbv). The action level
is considered to be protective of public health. Breathing benzene for
a lifetime at 0.95 ppbv is very unlikely to be harmful to people. If
benzene concentrations in air are above the action level, we recommend
taking an action to halt exposure.
You can smell benzene when the level reaches 5,000 ppbv. If you can
smell the chemical, the level is too high to be safe.
Will exposure to benzene result in harmful health effects?
Drowsiness, headaches, and dizziness have been reported when people breathed air with
benzene levels of more than 10 ppm (10,000 ppbv) for a short time.
The following health effects can occur after several years of exposure to benzene:
Cancer: Long-term exposure to benzene can increase the risk of
Reproductive Effects: Animal studies show that inhaling benzene vapors
can damage reproductive organs and cause infertility. Exposure to benzene in workplaces
has caused menstrual variations.
Organ Systems: Exposure to benzene can cause anemia and weaken the
In general, chemicals affect the same organ systems in all people who are exposed.
However, the seriousness of the effects may vary from person to person.
A person's reaction depends on several things, including individual health, heredity,
previous exposure to chemicals including medicines, and personal habits such as smoking or
It is also important to consider the length of exposure to the chemical; the amount of
chemical exposure; and whether the chemical was inhaled, touched, or eaten.
What can I do to decrease my exposure to benzene?
A primary source of benzene exposure is from automotive gasoline.
- When dispensing gasoline, avoid
breathing the vapors.
- Store gasoline in air-tight
- Do not dispense or handle gasoline in your home or garage.
- Take containers and gasoline
operated machinery outside, away from the house, when
filling to allow for ventilation.
Can a medical test determine exposure to benzene?
Benzene breaks down in the body to several other compounds. Those compounds can be
found in the blood or urine of people who have been exposed to high levels of benzene
within the past two days. Tests will prove an exposure to benzene occurred but will not
predict the kind of illness that could result. We do not know what level of benzene
break-down products are common in most people, since most people are regularly exposed to
some amount of benzene.
People who think they have been exposed to benzene over a long period of time should
contact their doctor. Physicians can use blood chemistry, liver function and kidney
Seek medical advice if you have any symptoms that you think may be related to chemical
(P-44341 Revised 05/2012)
This fact sheet summarizes information about this chemical and is not a complete
listing of all possible effects. It does not refer to work exposure or emergency
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