1.1 What is 2-butanone? |
1.2 How might I be exposed to 2-butanone? |
1.3 How can 2-butanone enter and leave
my body? |
1.4 How can 2-butanone affect my health? |
1.5 Is there a medical test to determine
whether I have been exposed to 2-butanone? |
1.6 What recommendations has the federal
government made to protect human health? |
1.7 Where can I get more information? |
References |
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July 1992 |
Public Health Statement |
for |
2-Butanone |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for 2-butanone. 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
2-butanone (methyl ethyl ketone) and to emphasize the human
health effects that may result from exposure to it. The Environmental
Protection Agency (EPA) has identified 1,177 sites on its
National Priorities List (NPL). 2-Butanone has been found
at 137 of these sites. However, we do not know how many of
the 1,177 NPL sites have been evaluated for 2-butanone. As
EPA evaluates more sites, the number of sites at which 2-butanone
is found may change. The information is important for you
because 2-butanone may cause harmful health effects and because
these sites are potential or actual sources of human exposure
to 2-butanone.
When a chemical 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 as a chemical emission. This emission,
which is also called a release, does not always lead to exposure.
You are exposed to a chemical only when you come into contact
with the chemical. You may be exposed to it in the environment
by breathing, eating, or drinking substances containing the
chemical or from skin contact with it.
If you are exposed to a hazardous substance such as 2-butanone,
several 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, sex, nutritional status, family
traits, life style, and state of health.
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1.1
What is 2-butanone? |
2-Butanone, also known as methyl ethyl ketone (MEK), is a
colorless liquid with a sweet, but sharp odor. 2-Butanone
is manufactured in large amounts for use in paints, glues,
and other finishes because it rapidly evaporates and will
dissolve many substances. It will quickly evaporate into the
air. 2-Butanone is often found dissolved in water or as a
gas in the air. 2-Butanone is also a natural product made
by some trees and is found in some fruits and vegetables.
The exhausts of cars and trucks release 2-butanone into the
air. 2-Butanone is usually found in the air, water, and soil
of landfills and hazardous waste sites.
In water, 2-butanone can be changed to a more simple chemical
form by natural biological processes and will be broken down
in about 2 weeks. It will not be deposited in the sediment
of rivers or lakes, and it is not expected to concentrate
in fish. In air, 2-butanone will break down under the influence
of sunlight, although it does not react with sunlight directly.
One-half of any given amount of 2-butanone in the air will
break down in 1 day or less. It is not known if 2-butanone
changes to a more simple form by natural biological processes
in soil, but it is expected to do so because similar substances
are broken down by these processes. 2-Butanone will not stick
to soil, and if it is spilled onto soil, it will travel through
the soil into underground water sources. Some of the 2-butanone
found in soil or water will also evaporate to the air.
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1.2
How might I be exposed to 2-butanone? |
2-Butanone can enter the environment in a number of different
ways. It can enter the air or water from the waste of manufacturing
plants. 2-Butanone is present in many different types of paints
and glues used both in the home and in industry. As these
products dry, 2-butanone will enter the air. 2-Butanone is
also in air because it is released in the exhaust of cars
and trucks. Some trees in the forest release 2-butanone to
the air.
We do not know the background levels of 2-butanone in air,
water, or soil. We know that 2-butanone is found naturally
in some foods. We know it is found at hazardous waste sites,
and it is also found occasionally in drinking water and often
in the air of cities. You may also be exposed to 2-butanone
by smoking cigarettes.
You may be exposed to higher levels of 2-butanone if you
use glues or coatings containing it in a small enclosed area
that does not have good air flow. People who use it at work
have a good chance of being exposed to 2-butanone. 2-Butanone
is used in such industries as shoe factories, printing plants,
plastics factories, and sporting goods manufacturers. People
who live near a toxic waste site where 2-butanone is kept
may breathe it if it evaporates into the air, or drink it
if it gets into the water supply, especially when the water
supply comes from wells.
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1.3
How can 2-butanone enter and leave my body? |
2-Butanone can enter your body if you
breathe air that contains it, through your skin if it touches
you, or through your mouth if you eat food or drink water
that has 2-butanone in it. Studies have shown that, if there
is 2-butanone in the air you breathe, at least half of what
you breathe in will enter your body. The other half will leave
in the air you breathe out. We do not know how much 2-butanone
will stay in your body if you drink it or if it touches your
skin. The amount of 2-butanone that actually enters your body
depends on how much is in the air you breathe, how much is
in your food or water, or how much gets on your skin. The
amount of 2-butanone that enters your body also depends on
how long you breathe it or how long it is on your skin before
you wash it off. Your body gets rid of 2-butanone in urine
and in the air you breathe out. 2-Butanone is not a chemical
that stays in your body for very long; it will be gone by
the next day.
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1.4
How can 2-butanone affect my health? |
Some people who breathed air that contained 2-butanone first
noticed its sweet, sharp odor at a concentration of 5-8 parts
of 2-butanone per million parts of air (5-8 ppm). The main
health effects that have been seen in humans who breathed
higher concentrations of 2-butanone are mild irritation of
the nose, throat, eyes, and skin.
Serious health effects in animals have been seen only at
very high concentrations of 2-butanone. These high concentrations
are not expected in the usual use of 2-butanone or in the
vicinity of hazardous waste sites. Studies in animals have
shown that 2-butanone does not cause serious damage to the
nervous system or the liver, but mice that breathed low levels
for a short time had temporary behavioral effects. 2-Butanone
alone does not have serious effects on the liver or nervous
system, but it can cause other chemicals to become more harmful
to these systems.
Guinea pigs, rats, and mice that breathed
high levels of 2-butanone for a short time became unconscious
and died. Pregnant rats and mice that breathed air containing
high levels of 2-butanone had underdeveloped fetuses. The
rats that swallowed very high concentrations of 2-butanone
in water also developed signs of nervous system effects such
as inactivity, drooping eye lids, and uncoordinated muscle
movement. Some rats and mice that swallowed water containing
high concentrations of 2-butanone died. Rats that received
water containing a lower concentration of 2-butanone had mild
kidney damage. Skin irritation developed in rabbits and guinea
pigs that had small amounts of 2-butanone dropped on their
skin. Rabbits that had small amounts of 2-butanone dropped
in their eyes had serious eye irritation. We do not know whether
2-butanone causes birth defects or affects reproduction in
humans. Reproductive effects were not seen in animals exposed
to 2-butanone. We have no information about whether 2-butanone
causes cancer in humans or animals.
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1.5
Is there a medical test to determine whether I have been exposed
to 2-butanone? |
No specific medical test is available
to determine whether you have been exposed to 2-butanone.
Studies in humans and animals have shown that it is possible
to detect 2-butanone or its breakdown products in the blood,
breath, and urine. The levels of 2-butanone found in the blood,
breath, and urine are usually associated with the levels of
exposure found in the workplace, but this is more useful for
determining exposure of groups of people rather than individuals.
Tests for 2-butanone in blood, urine, or breath are useful
only for recent exposure because 2-butanone and its breakdown
products leave the body rapidly.
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1.6
What recommendations has the federal government made to protect
human health? |
The Occupational Safety and Health Administration
(OSHA) has set an occupational exposure limit of 200 ppm of
2-butanone in the air. The National Institute for Occupational
Safety and Health (NIOSH) has also recommended 200 ppm of
2-butanone as the limit for up to a 10-hour work shift in
a 40-hour workweek. Because of its odor, you can smell 2-butanone
before it harms you.
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1.7
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). 1992. Toxicological
profile for 2-butanone. Atlanta, GA: U.S. Department of
Health and Human Services, Public Health Service.
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