September 1995 |
ToxFAQs™ |
for |
4,4'-Methylenebis(2-Chloroaniline)(MBOCA) |
(Metileno
Bis-ortocloro anilina (MBOCA)) |
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This fact sheet answers the most frequently
asked health questions about 4,4'-methylenebis(2-chloroaniline)(MBOCA).
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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SUMMARY: Exposure to 4,4'-methylenebis(2-chloroaniline)
(MBOCA) happens mostly in the workplace by touching it
or by breathing contaminated air. MBOCA is suspected of
causing bladder cancer in people and animals. This chemical
has been found in at least 4 of 1,416 National Priorities
List sites identified by the Environmental Protection
Agency. |
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What
is 4,4'-methylenebis(2-chloroaniline)(MBOCA)? |
MBOCA is a synthetic chemical used primarily
to make polyurethane products. Pure MBOCA is a colorless,
crystalline solid, but the commonly used form is usually yellow,
tan, or brown pellets. It has no smell or taste.
Examples of these products include gears,
gaskets, sport boots, roller skate wheels, shoe soles, rolls
and belt drives in cameras, computers and copy machines, wheels
and pulleys for escalators and elevators, components in home
appliances, and various military applications. It is also
used as a coating in chemical reactions to "set" glues, plastics,
and adhesives. Because plastics have many uses, MBOCA is widely
used.
Other names for MBOCA include 4,4'-methylenebis(2-chloroaniline),
methylene-bis-ortho-chloro-aniline, bis-amine, DACPM, MCA,
and MOCA.
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What
happens to 4,4'-methylenebis(2-chloroaniline)(MBOCA) when it
enters the environment? |
- It enters the environment from the disposal of solid waste
from manufacturing plants that use MBOCA.
- It doesn't dissolve in water easily.
- MBOCA sticks strongly to soil particles.
- It is not likely to enter groundwater.
- MBOCA is not likely to evaporate from soil or water.
- It is broken down by sunlight in air and by microscopic
organisms in soil or water.
- Levels of MBOCA can build up in the roots of vegetables
grown in contaminated soil.
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How
might I be exposed to 4,4'-methylenebis(2-chloroaniline)(MBOCA)? |
- People who work with MBOCA may get it on their skin and
breathe it in air. Skin contact is the most common way to
be exposed.
- It is sometimes found in root crops (such as carrots and
beets) that people eat if the plants were grown in soil
containing MBOCA.
- People may be exposed through skin contact with soil contaminated
with MBOCA or near waste sites or landfills.
- It is not usually found in drinking water.
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How
can 4,4'-methylenebis(2-chloroaniline)(MBOCA) affect my health? |
There is not much information on how
MBOCA can affect people's health. Studies of human exposure
suggest that the small amounts of MBOCA usually found in the
air or on surfaces in or near factories do not cause toxic
effects. Exposure to large amounts of MBOCA may cause harm,
but no such exposures have been reported. We do not know if
there are any other long-term health effects in people caused
by MBOCA, other than cancer.
One man was accidentally sprayed in his
face with hot MBOCA. He felt nauseated and his kidneys were
affected, but these effects lasted less than one day. MBOCA
is harmful to blood cells and the liver in dogs and rats.
Researchers do not know if MBOCA causes
birth defects in people.
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How
likely is 4,4'-methylenebis(2-chloroaniline)(MBOCA) to cause
cancer? |
The Department of Health and Human Services
has determined that MBOCA may reasonably be anticipated to
be a carcinogen.
MBOCA is suspected of causing bladder
cancer in people. Information is being gathered to determine
whether bladder cancer in people may result from short-, medium-,
or long-term exposures to MBOCA. A few studies have found
an above-normal number of bladder tumors in workers exposed
to MBOCA for several years. It caused lung, liver, breast,
and bladder cancer in rats, mice, and dogs that ate MBOCA
for over a year.
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Is
there a medical test to show whether I've been exposed to 4,4'-methylenebis(2-chloroaniline)(MBOCA)? |
Laboratory tests can measure MBOCA in
urine. The test must be done within a short period after you
are exposed because it is broken down quickly by your body.
The test does not tell how much MBOCA you've been exposed
to or if harmful effects will occur. The test is not routinely
available at your doctor's office, but a sample taken in the
doctor's office can be shipped to a special laboratory if
necessary.
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Has the federal government made recommendations to protect human health? |
The Environmental Protection Agency (EPA)
has classified MBOCA as a hazardous waste that must meet specific
disposal requirements. The EPA requires that spills or accidental
releases of MBOCA into the environment of 10 pounds or more
must be reported to EPA.
The American Conference of Governmental
Industrial Hygienists (ACGIH) set a maximum level of 0.11
milligrams of MBOCA per cubic meter (0.11 mg/m³) of workplace
air for an 8-hour workday, 40-hour workweek.
The National Institute for Occupational
Safety and Health (NIOSH) recommends an exposure limit of
3 micrograms of MBOCA per cubic meter of air (3 mg/m³)
over a 10-hour day.
These agencies advise avoiding eye and
skin contact because this may be a route of significant exposure.
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Glossary |
Carcinogen: A substance that can cause
cancer.
Microgram (mg): One millionth of a gram.
Milligram (mg): One thousandth of a gram.
Tumor: An abnormal mass of tissue.
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1994. Toxicological Profile for 4,4'-methylenebis(2-chloroaniline) (MBOCA).
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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