1.1 What is 4,4'-methylenedianiline? |
1.2 What happens to 4,4'-methylenedianiline
when it enters the environment? |
1.3 How might I be exposed to 4,4'-methylenedianiline? |
1.4 How can 4,4'-methylenedianiline enter
and leave my body? |
1.5 How can 4,4'-methylenedianiline affect
my health? |
1.6 Is there a medical test to determine
whether I have been exposed to 4,4'-methylenedianiline? |
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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August 1998 |
Public Health Statement |
for |
4,4'-Methylenedianiline |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for 4,4'-methylenedianiline. 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 public health statement tells you
about 4,4'-methylenedianiline and the effects of exposure.
The Environmental Protection Agency (EPA)
identifies the most serious hazardous waste sites in the nation.
These sites make up the National Priorities List (NPL) and
are the sites targeted for long-term federal clean-up activities.
4,4'-Methylenedianiline has not been found in any of the 1,445
current or former NPL sites. However, the total number
of NPL sites evaluated is not known. As more sites are
evaluated, the number of sites at which 4,4'-methylenedianiline
is found may increase. This is important because exposure
to this substance may harm you and because these sites may
be sources of exposure.
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 by breathing, eating, touching, or drinking.
If you are exposed to 4,4'-methylenedianiline,
many factors determine whether you'll be harmed. These
factors include the dose (how much), the duration (how long),
and how you come in contact with it. You must also consider
the other chemicals you're exposed to and your age, sex, diet,
family traits, lifestyle, and state of health.
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1.1
What is 4,4'-methylenedianiline? |
Methylenedianiline exists in several
very similar forms. Of these various forms, 4,4'-methylenedianiline
is the form used by industries. This profile discusses
this important form of methylenedianiline. Other forms
of methylenedianiline are only used as laboratory chemicals
and have no commercial uses at this time. 4,4'-Methylenedianiline
is also commonly known as diaminodiphenylmethane or MDA.
It is a colorless (like an ice cube) to pale yellow solid
with a faint amine odor (sharp odor). The taste of the
compound is not known. It is very slightly soluble in
water (does not mix well with water) and does not readily
evaporate at room temperature. If left in an open container,
it slowly turns brown because of chemical reactions with components
present in air.
4,4'-Methylenedianiline is an industrially
produced compound that is not known to occur naturally.
It is produced by industries mainly for making polyurethane
foams (such as insulating materials in mailing containers).
Smaller amounts are used for making coating materials, epoxy
resins (glues), Spandex® fiber, and dyes and for other
purposes.
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1.2
What happens to 4,4'-methylenedianiline when it enters the environment? |
Most 4,4'-methylenedianiline enters the
environment when it's produced or when it's used to make other
compounds. Of the total environmental release of at
least 20,000 pounds per year, 52.6% is released to the air
and 45% is released to deep soil during underground injection.
Only 2.4% of the total is released to land and water.
In addition, about 2,000 pounds per year are transferred to
public sewer systems for treatment. No estimate is available
for the amounts of 4,4'-methylenedianiline that enter the
environment from accidental spills or from identified hazardous
waste sites that may contain 4,4'-methylenedianiline.
The lack of experimental data makes it
difficult to be certain about what happens to 4,4'-methylenedianiline
when it enters the environment. In air, 4,4 '-methylenedianiline
will mostly be present as tiny particles and will eventually
return to land and water by settling and by being brought
down in rain and snow. In water, most of the 4,4'-methylenedianiline
will tend to attach itself to particles and sediments, and
will eventually settle to the bottom. 4,4'-Methylenedianiline
present in water and sediment will eventually be broken down
by bacteria and other microorganisms. This process may
take as long as 10–40 days. 4,4'-Methylenedianiline
does not tend to build up in the food chain, and it is uncertain
whether it accumulates in fish. When deposited on soil,
4,4'-methylenedianiline will become strongly attached to it
and, as a result, will not move quickly with rainwater into
deeper groundwater. Bacteria and microorganisms present
in soil will break down 4,4'-methylenedianiline, but the process
may take as long as 10 days.
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1.3
How might I be exposed to 4,4'-methylenedianiline? |
You are most likely to be exposed to
4,4'-methylenedianiline if you work with it. The general
population may be exposed to extremely low levels of 4,4'-methylenedianiline
through consumer goods such as polyurethane cushioning or
products that contain epoxy. The Food and Drug Administration
(FDA) reports that the level of exposure to 4,4'-methylenedianiline
through food is virtually zero. People who live near
hazardous waste sites that contain 4,4'-methylenedianiline
are susceptible to exposure if dust particles containing the
substance are released from the waste site, enter the air,
and are breathed into the body. Children playing near
these sites may be exposed by touching and eating soil that
contains 4,4'-methylenedianiline. However, there is
no experimental or estimated value for the intake of 4,4'-methylenedianiline
by the general population.
People who work in the following industries
can be exposed to 4,4'-methylenedianiline by breathing in
the dust or aerosol, or by getting it on their skin:
manufacture, formulation, and packaging of 4,4'-methylenedianiline;
certain paint making industries that use epoxy materials;
pattern and tool making with polyurethane; potting and encapsulation
with polyurethane; and casting and molding with resins made
with 4,4'-methylenedianiline. 4,4'-Methylenedianiline
has been detected in workplace air, in skin patches worn by
workers, and in the urine of workers in these industries.
However, the level in work atmospheres rarely exceeds the
level of 0.8 milligram (mg) of 4,4'-methylenedianiline in
a cubic meter of air (1 mg is equivalent to a thousandth of
a gram), which is suggested as a safe level by the American
Conference of Governmental Industrial Hygienists (ACGIH).
The maximum exposure was found to occur in workers in the
manufacturing and formulating industries. People with
kidney diseases or who need frequent blood transfusions may
be exposed to tiny amounts of 4,4'-methylenedianiline during
their treatment by machines like dialyzers. The compound
is released from polyurethane parts of equipment when they
are sterilized with radiation or heat.
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1.4
How can 4,4'-methylenedianiline enter and leave my body? |
If you breathe air containing dust contaminated
with 4,4 -methylenedianiline, it can enter your body through
your lungs and pass into the bloodstream. We do not
know how much of the 4,4'-methylenedianiline will pass into
your bloodstream or how fast this will happen. If you
swallow food, water, or soil contaminated with 4,4'-methylenedianiline,
some of it will probably enter your body and pass from the
stomach into the bloodstream, but we do not know how much
or how fast this will occur. If you touch soil containing
4,4 -methylenedianiline (for example, at a hazardous waste
site), some 4,4'-methylenedianiline will pass through the
skin into the bloodstream, but we do not know how much or
how fast. For people living around waste sites, or processing
or storage facilities, the most likely way it will enter their
bodies is from skin contact with contaminated soil.
For people who work with or around 4,4'-methylenedianiline,
skin contact with contaminated dirt particles is the most
likely way it will enter the body. Once 4,4'-methylenedianiline
is in your body, it may change into other related chemicals
called metabolites. We think that some metabolites of
4,4'-methylenedianiline may be more harmful than unchanged
4,4'-methylenedianiline, but there is no conclusive experimental
evidence to support this assumption. Some of the metabolites
may leave your body in the urine within hours. We do
not know if 4,4'-methylenedianiline is stored in the body.
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1.5
How can 4,4'-methylenedianiline affect my health? |
Studies in the workplace suggest that
exposure to 4,4'-methylenedianiline may cause skin irritation
and can damage your liver. People who ate bread that
was accidentally contaminated with 4,4 -methylenedianiline
also experienced liver damage. We do not know, however,
how much 4,4'-methylenedianiline was in the bread. We
do not know if breathing air contaminated with 4,4'-methylenedianiline,
or eating contaminated food, or skin contact affects human
reproduction or development. We also do not know if
4,4'-methylenedianiline affects the nervous system or the
ability to fight disease in humans.
To protect the public from the harmful
effects of toxic chemicals and to find ways to treat people
who have been harmed, scientists use many tests.
One way to see if a chemical will hurt
people is to learn how the chemical is absorbed, used, and
released by the body; for some chemicals, animal testing may
be necessary. Animal testing may also be used to identify
health effects such as cancer or birth defects. Without
laboratory animals, scientists would lose a basic method to
get information needed to make wise decisions to protect public
health. Scientists must treat research animals with
care and compassion. Laws today protect the welfare
of research animals, and scientists must comply with strict
animal care guidelines.
Some mice that drank water containing
large amounts of 4,4'-methylenedianiline for a short period
died as a result. Rats that ate food or drank water
containing smaller amounts of 4,4'-methylenedianiline for
months or years had liver damage and thyroid gland injuries.
Only a small amount of information exists on the health effects
in animals exposed to 4,4'-methylenedianiline by breathing
or skin contact. This information indicates that guinea
pigs that breathed air contaminated with a very high amount
of 4,4'-methylenedianiline for 2 weeks suffered damage to
their eyes. Rabbits that received repeated skin exposure
to relatively high amounts of 4,4'-methylenedianiline also
had liver damage. There is not enough information to
determine if exposure to 4,4'-methylenedianiline affects reproduction,
development, the nervous system, or the ability to fight disease
in animals.
There is not enough information on workers
to determine if 4,4'-methylenedianiline is carcinogenic (causes
cancer) in people. Rats and mice that drank water containing
4,4'-methylenedianiline throughout their lives developed cancer
in their liver and thyroid glands. The International
Agency for Research on Cancer (IARC) has determined that 4,4'-methylenedianiline
is possibly carcinogenic to humans.
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1.6
Is there a medical test to determine whether I have been exposed
to 4,4'-methylenedianiline? |
Samples of your urine can be tested to
find out if you have recently been exposed to 4,4'-methylenedianiline.
These tests will only confirm if you have been exposed.
They cannot estimate how much of it has entered your body
and will not tell you whether your health will be affected
by exposure to 4,4'-methylenedianiline. The exposure
tests are not routinely available in hospitals and clinics
because they require special analytical equipment and must
be specially requested by your physician.
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1.7
What recommendations has the federal government made to protect
human health? |
The federal government develops regulations
and recommendations to protect public health. Regulations
can be enforced by law. Federal agencies that develop
regulations for toxic substances include the Environmental
Protection Agency (EPA), the Occupational Safety and Health
Administration (OSHA), and the Food and Drug Administration
(FDA). Recommendations provide valuable guidelines to
protect public health but cannot be enforced by law.
Federal organizations that develop recommendations for toxic
substances include the Agency for Toxic Substances and Disease
Registry (ATSDR) and the National Institute for Occupational
Safety and Health (NIOSH).
Regulations and recommendations can be
expressed in not-to-exceed levels in air, water, soil, or
food that are usually based on levels that affect animals;
then they are adjusted to help protect people. Sometimes
these not-to-exceed levels differ among federal organizations
because of different exposure times (an 8-hour workday or
a 24-hour day), the use of different animal studies, or other
factors.
Recommendations and regulations are also
periodically updated as more information becomes available.
For the most current information, check with the federal agency
or organization that provides it. Some regulations and
recommendations for 4,4 -methylenedianiline include the following:
NIOSH recommends that workers should
not breathe air that contains more than 0.03 milligram of
4,4'-methylenedianiline per cubic meter of air (0.03 mg/m³)
during a 10-hour workday, 40-hour workweek.
OSHA recommends that workers should not
be exposed to more than 0.081 mg/m³
4,4'-methylenedianiline during an 8-hour workday.
ACGIH recommends that workers should
not be exposed to more than 0.81 mg/m³
4,4'-methylenedianiline for an 8-hour workday, 40-hour workweek.
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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). 1998. Toxicological
profile for 4,4'-methylenedianiline. Atlanta, GA: U.S.
Department of Health and Human Services, Public Health Service.
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