September 2001 |
ToxFAQs™ |
for |
Benzidine |
(Bencidina) |
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This fact sheet answers the most frequently
asked health questions about benzidine. For more information,
you may call the ATSDR Information Center at 1-888-422-8737.
This fact sheet is one in a series of summaries about hazardous
substances and their health effects. This information is important
because this substance may harm you. The effects of exposure
to any hazardous substance depend on the dose, the duration,
how you are exposed, personal traits and habits, and whether
other chemicals are present.
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HIGHLIGHTS: Benzidine is a
manufactured chemical that was used to produce dyes. Most
people are not exposed to benzidine in the environment.
Occupational exposure has been associated with increased
risk of urinary bladder cancer. This substance has been
found in at least 28 of the 1,585 National Priorities
List sites identified by the Environmental Protection
Agency (EPA). |
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What
is benzidine? |
Benzidine is a manufactured chemical
that does not occur naturally. It is a crystalline solid that
may be grayish-yellow, white, or reddish-gray. In the environment,
benzidine is found in either its "free" state (as an organic
base), or as a salt. Benzidine was used to produce dyes for
cloth, paper, and leather. It is no longer produced or used
commerically in the U.S.
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What
happens to benzidine when it enters the environment? |
- Benzidine in the air exists as a vapor or attached to
very small particles. The benzidine in air will eventually
settle over land and water.
- Only very small amounts of free benzidine will dissolve
in water; benzidine salts can dissolve more readily in water.
Benzidine released into waterways will sink and become part
of the bottom sludge.
- Benzidine in soil is likely to be strongly attached to
soil particles and will not easily pass into underground
water.
- Benzidine is not likely to accumulate in the food chain.
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How
might I be exposed to benzidine? |
- The general population is not likely to be exposed to
benzidine through contaminated air, water, soil, or food.
- People living near uncontrolled hazardous waste sites
may be exposed to benzidine.
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How
can benzidine affect my health? |
Except for the cancer discussed next,
benzidine has not been definitely shown to cause major adverse
health effects in humans. If it comes in contact with your
skin it may cause a skin allergy. Liver, kidney, immune, and
neurological effects have been observed in laboratory animals
given relatively high amounts of benzidine. We do not know
if these effects would also occur in humans.
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How
likely is benzidine to cause cancer? |
It is known that long term occupational
exposure to benzidine can increase the risk of developing
cancer in people. The main type of cancer found in workers
is cancer of the urinary bladder. The Department of Health
and Human Services (DHHS), the World Health Organization (WHO),
and the EPA have determined that benzidine is a human carcinogen.
In addition, dyes made from benzidine,
such as Direct Blue 6, Direct Black 38, and Direct Brown 95,
have been shown to cause cancer in humans. The DHHS has determined
that Direct Blue 6 and Direct Black 38 cause cancer in animals
and WHO determined that Direct Blue 6, Direct Black 38, and
Direct Brown 95 cause cancer in animals.
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How
can benzidine affect children? |
There are no studies on health effects
on children exposed to benzidine. It is likely that health
effects seen in children exposed to high levels of benzidine
will be similar to the effects seen in adults.
We do not know if exposure to benzidine
will result in birth defects or other developmental effects
in people.
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How
can families reduce the risk of exposure to benzidine? |
- Most families will not be exposed to benzidine.
- Children should avoid playing in soils near uncontrolled
hazardous waste sites where benzidine may have been discarded.
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Is
there a medical test to show whether I've been exposed to benzidine? |
Benzidine and its breakdown products
can be detected in your urine, but only within about 2 weeks
after your last exposure. Benzidine and its breakdown products
can also bind to proteins within your red blood cells, and
this can be detected for up to 4 months. These tests are not
usually available at your doctor's office, but your doctor
can send the samples to a laboratory that can perform the
tests. None of these tests, however, can predict whether you
will experience any health effects.
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Has the federal government made recommendations to protect human health? |
The EPA recommends that the amount of
benzidine in drinking water be less than 1 part benzidine
in a trillion parts of water (1 ppt).
The Food and Drug Administration (FDA)
allows a maximum of 1 part benzidine per billion parts of
some color additives for food.
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 2001. Toxicological
Profile for benzidine. Update. Atlanta, GA: U.S. Department
of Health and Human Services, Public Health Service.
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Where can I get more information? |
ATSDR can tell you where to find occupational
and environmental health clinics. Their specialists can recognize,
evaluate, and treat illnesses resulting from exposure to hazardous
substances. You can also contact your community or state health
or environmental quality department if you have any more questions
or concerns. For more information, contact:
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Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Phone: 1-888-42-ATSDR (1-888-422-8737)
FAX: (770)-488-4178
Email: ATSDRIC@cdc.gov
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