July 1999 |
ToxFAQs™ |
for |
Nitrobenzene |
(Nitrobenceno) |
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This fact sheet answers the most frequently
asked health questions about nitrobenzene. 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: Nitrobenzene is
used mainly as an intermediate to produce another chemical.
Repeated exposures to high levels result in a blood disorder
in people. This chemical has been found in at least 7
of the 1,177 National Priorities List sites identified
by the Environmental Protection Agency (EPA). |
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What
is nitrobenzene? |
Nitrobenzene is an industrial chemical.
It is an oily yellow liquid with an almond-like odor. It dissolves
only slightly in water and will evaporate to air.
It is produced in large quantities for
use in industry. Most of the nitrobenzene produced in the
United States is used to manufacture a chemical called aniline.
Nitrobenzene is also used to produce lubricating oils such
as those used in motors and machinery. A small amount of nitrobenzene
is used in the manufacture of dyes, drugs, pesticides, and
synthetic rubber.
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What
happens to nitrobenzene when it enters the environment? |
- Very low levels of nitrobenzene may be found in air.
- It may be present in water from industrial releases.
- In water, nitrobenzene will be broken down by sunlight.
- Nitrobenzene in soil can move into the groundwater, be
taken up by plants, evaporate to the air, and be broken
down by bacteria.
- It does not appear to concentrate in fish or other aquatic
animals.
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How
might I be exposed to nitrobenzene? |
- Breathing air containing it.
- Living near a factory where it is used.
- Working in a factory that produces nitrobenzene.
- Living near a hazardous waste site where it has been disposed
of.
- Working as a chemist or in other occupations where nitrobenzene
is used.
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How
can nitrobenzene affect my health? |
A small amount of nitrobenzene may cause
mild irritation if it contacts the skin or eyes directly.
Repeated exposures to a high concentration of nitrobenzene
can result in methemoglobinemia, a condition in which the
blood's ability to carry oxygen is reduced. If you have this
condition, your skin may turn a bluish color and you may have
nausea, vomiting, and shortness of breath. Effects such as
headache, irritability, dizziness, weakness, and drowsiness
may also occur. There is also some evidence that breathing
high concentrations of nitrobenzene may damage the liver.
Animal studies have reported effects
on the blood and liver from exposure to nitrobenzene. A single
dose of nitrobenzene fed to male rats resulted in damage to
the testicles and decreased levels of sperm.
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How
likely is nitrobenzene to cause cancer? |
No studies are available on whether nitrobenzene
causes cancer in people. In animals, breathing nitrobenzene
resulted in an increase in liver, thyroid, and kidney tumors.
The International Agency for Research
on Cancer (IARC) has determined that nitrobenzene is possibly
carcinogenic to humans.
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Is
there a medical test to show whether I've been exposed to nitrobenzene? |
Nitrobenzene reacts with red blood cells
in the body to produce methemoglobin. If you have recently
been exposed to nitrobenzene, the level of methemoglobin in
your body may be elevated, and this can be measured. However,
since other toxic chemicals also produce methemoglobin, this
method does not definitely show that you were exposed to nitrobenzene.
In cases of long-term exposure to nitrobenzene,
the presence of its breakdown products, p-nitrophenol and
p-aminophenol, in the urine indicates nitrobenzene exposure.
These tests require special equipment and cannot be routinely
done in a doctor's office. The results of these tests cannot
be used to determine the level of nitrobenzene exposure or
if harmful health effects can be expected to occur.
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Has the federal government made recommendations to protect human health? |
The EPA recommends that levels in lakes
and streams should be limited to 17 parts of nitrobenzene
per million parts of water (17 ppm) to prevent possible health
effects from drinking water or eating fish contaminated with
nitrobenzene.
The EPA requires that discharges, spills,
or accidental releases of 1,000 pounds or more of nitrobenzene
must be reported to the EPA.
The Occupational Safety and Health Administration
(OSHA) has set a permissible exposure limit of 5 milligrams
nitrobenzene per cubic meter of air (5 mg/m³)
for an 8-hour workday in a 40-hour workweek.
The American Conference of Governmental
and Industrial Hygienists (ACGIH) and the National Institute
for Occupational Safety and Health (NIOSH) also recommend
an occupational exposure limit of 5 mg/m³
for nitrobenzene.
The federal recommendations have been
updated as of July 1999.
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Glossary |
Carcinogenic: Able to cause cancer.
Evaporate: To change into a vapor or
a gas.
Milligram (mg): One thousandth of a gram.
National Priorities List: A list of the
nation's worst hazardous waste sites.
Pesticide: A substance that kills pests.
ppm: Parts per million.
Tumor: An abnormal mass of tissue.
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1990. Toxicological Profile for nitrobenzene. 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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