1.1 What is MBOCA? |
1.2 What happens to MBOCA when it enters
the environment? |
1.3 How might I be exposed to MBOCA? |
1.4 How can MBOCA enter and leave my body? |
1.5 How can MBOCA affect my health? |
1.6 Is there a medical test to determine
whether I have been exposed to MBOCA? |
1.7 What recommendations has the federal
government made to protect human health? |
1.8 Where can I get more information? |
References |
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May 1994 |
Public Health Statement |
for |
4,4'-Methylenebis (2-chloroaniline)
(MBOCA) |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for 4,4'-methylenebis (2-chloroaniline) (MBOCA).
It is one in a series of Public Health Statements about hazardous
substances and their health effects. A shorter version, the
ToxFAQs™, is also available.
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. For more
information, call the ATSDR Information Center at 1-888-422-8737.
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This Statement was prepared to give you
information about 4,4'- methylenebis(2-chloroaniline) (MBOCA)
and to emphasize the human health effects that may result
from exposure to it. The Environmental Protection Agency (EPA)
has identified 1,350 hazardous waste sites as the most serious
in the nation. These sites comprise the "National Priorities
List" (NPL): Those sites which are targeted for long-term
federal cleanup activities. MBOCA has been found in at least
4 of the sites on the NPL. As EPA evaluates more sites, the
number of sites at which MBOCA is found may increase. This
information is important because exposure to MBOCA may cause
harmful health effects and because these sites are potential
or actual sources of human exposure to MBOCA.
When a substance is released from a large
area, such as an industrial plant, or from a container, such
as a drum or bottle, it enters the environment. This release
does not always lead to exposure. You can be exposed to a
substance only when you come in contact with it. You may be
exposed by breathing, eating, or drinking substances containing
the substance or by skin contact with it.
If you are exposed to a substance such
as MBOCA, many factors will determine whether harmful health
effects will occur and what the type and severity of those
health effects will be. These factors include the dose (how
much), the duration (how long), the route or pathway by which
you are exposed (breathing, eating, drinking, or skin contact),
the other chemicals to which you are exposed, and your individual
characteristics such as age, gender, nutritional status, family
traits, lifestyle, and state of health.
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1.1
What is MBOCA? |
MBOCA is a synthetic chemical used in
industry primarily to produce castable polyurethane parts.
It also has a coating application when used in chemical reactions
to "set" glues, plastics, and adhesives. Since plastics have
many uses, MBOCA is used very frequently. Other names for
MBOCA include 4,4'-methylenebis(2- chloroaniline), bis amine,
DACPM, MCA, methylene bis ortho chloroaniline, and MOCA. The
name MBOCA comes from methylene bis ortho chloro aniline.
Pure MBOCA is a colorless solid, but MBOCA is usually made
and used as yellow, tan, or brown pellets. If MBOCA is heated
above 205°C it may decompose by itself. MBOCA has no
odor or taste.
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1.2
What happens to MBOCA when it enters the environment? |
MBOCA may enter the environment through
disposal of solid waste from manufacturing plants that use
MBOCA in castable polyurethane processing. MBOCA is not likely
to evaporate from the soil or water into the air. However,
it may enter the air as dust when it is used at production
plants, or it may enter surface waters from the waste streams
of these plants. Some of the MBOCA may be broken down by sunlight
or by tiny organisms, too small to be seen without the aid
of a microscope.
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1.3
How might I be exposed to MBOCA? |
Most exposure to MBOCA occurs in the
workplace. If you work with MBOCA, you may breathe small particles
of it in the air or get it on your skin if you brush against
a surface covered by MBOCA dust. There are several other ways
to be exposed to MBOCA outside of the workplace. For example,
you may be exposed to MBOCA if you live in an area where the
soil is contaminated with MBOCA. You may also be exposed if
you eat foods grown in soils that contain MBOCA. However,
you are unlikely to drink water contaminated with MBOCA because
it does not dissolve easily in water.
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1.4
How can MBOCA enter and leave my body? |
MBOCA can enter your bloodstream if you
breathe it in the air, eat it, or get it on your skin. Results
of studies in humans and animals show that MBOCA can enter
your body very quickly through the skin or lungs. Once MBOCA
is in your body, most of it leaves your body quickly. MBOCA
and its breakdown products exit the body through the urine
and feces. Results of studies in humans and animals show that
most MBOCA exits the body within a few days of exposure. The
small amount of MBOCA that may remain in your body after you
are exposed is likely to break down or leave your body at
a slow rate.
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1.5
How can MBOCA affect my 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,
other than cancer. However, it is possible that acute exposure
to a large amount of MBOCA, such as in the case of an industrial
accident, may produce effects that we do not know very much
about. Information on how MBOCA can affect your health is
very limited, and we do not know if there are any long-term
human health effects of exposure to MBOCA. MBOCA is suspected
of causing bladder cancer and is considered a probable human
carcinogen. Information is being gathered to determine whether
bladder cancer in humans may be a result of a short-, medium-,
or long-term exposure to MBOCA. We do not know if MBOCA causes
birth defects in humans.
Results of studies in animals show that
MBOCA can be harmful to the liver of exposed dogs and rats.
MBOCA also causes cancer of the lungs, liver, breast, and
bladder in animals. The Department of Health and Human Services
has determined that MBOCA may reasonably be anticipated to
be a carcinogen. The International Agency for Research on
Cancer has determined that MBOCA is probably carcinogenic
to humans. The EPA has determined that MBOCA is a probable
human carcinogen.
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1.6
Is there a medical test to determine whether I have been exposed
to MBOCA? |
There is a test that can measure MBOCA
in your urine within a few hours of exposure. This test, however,
will not detect exposure to MBOCA after a few days. This test
may not be commonly available in your doctor's office.
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1.7
What recommendations has the federal government made to protect
human health? |
The government has developed regulations
and guidelines for MBOCA. These are designed to protect the
public from the possible harmful health effects of this chemical.
EPA has classified MBOCA as a hazardous waste that must meet
certain disposal requirements.
The Occupational Safety and Health Administration
(OSHA) regulates levels of MBOCA in the workplace. The maximum
allowable amount of MBOCA in workroom air, assuming an 8-hour
workday and a 40-hour workweek, is 0.22 milligrams per cubic
meter.
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1.8 Where can I get more information? |
If you have any more questions or concerns, please contact
your community or state health or environmental quality department or:
Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Information line and technical assistance:
Phone: 888-422-8737
FAX: (770)-488-4178
ATSDR can also tell you the location of occupational and environmental health
clinics. These clinics specialize in recognizing, evaluating, and treating illnesses
resulting from exposure to hazardous substances.
To order toxicological profiles, contact:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone: 800-553-6847 or 703-605-6000
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1994. Toxicological
profile for MBOCA. Atlanta, GA: U.S. Department of Health
and Human Services, Public Health Service.
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