September 2003 |
ToxFAQs™ |
for |
Bromoform and Dibromochloromethane |
(Bromoformo
y Dibromoclorometano) |
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CAS#
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Bromoform 75-25-2 |
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Dibromochloromethane 124-48-1 |
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This fact sheet answers the most frequently
asked health questions about bromoform and dibromochloromethane.
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: Bromoform and dibromochloromethane
are formed as by-products when chlorine is added to water
supply systems. High levels of bromoform or dibromochloromethane
can damage the liver and kidneys and affect the brain.
Bromoform and dibromochloromethane have been found in
at least 141 and 172, respectively, of the 1,636 National
Priority List sites identified by the Environmental Protection
Agency (EPA). |
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What
are bromoform and dibromochloromethane? |
Bromoform and dibromochloromethane are
colorless to yellow, heavy, nonflammable, liquids with a sweet
odor. Small amounts are formed naturally by plants in the
ocean. They are somewhat soluble in water and readily evaporate
into the air. Most of the bromoform and dibromochloromethane
that enters the environment is formed as byproducts when chlorine
is added to drinking water to kill bacteria.
Only small quantities of bromoform and
dibromochloromethane currently are produced in the United
States. These chemicals were used in the past as solvents
and flame retardants, or to make other chemicals, but now
they are used mainly as laboratory reagents.
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What
happens to bromoform and dibromochloromethane when they enter
the environment? |
- When released to air, bromoform and dibromochloromethane
are slowly broken down by reactions with other chemicals
and sunlight or can be removed by rain.
- In water, these chemicals will evaporate to the air and/or
be broken down slowly by bacteria.
- When released to soil, most will evaporate to the air,
some will be broken down by bacteria, and some may filter
into the groundwater.
- Bromoform and dibromomethane do not build up in the food
chain.
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How
might I be exposed to bromoform and dibromochloromethane? |
- The most likely way people are exposed to bromoform and
dibromochloromethane is by drinking chlorinated water.
- You may breathe vapors released from chlorinated water
in a swimming pool or during showering and bathing.
- Some bromoform and dibromochloromethane may enter your
body directly through your skin while bathing or swimming.
- People that live near a waste site containing bromoform
or dibromochloromethane could be exposed by drinking contaminated
groundwater or breathing vapors released to the air.
- Exposure could occur by breathing bromoform and dibromochloromethane
in the air in or near a laboratory or factory that makes
or uses these chemicals; however, this is unlikely for most
people.
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How
can bromoform and dibromochloromethane affect my health? |
Eating or breathing a large amount of
bromoform slows down the normal brain activities and causes
sleepiness; this tends to go away within a day. Exposure to
very high amounts may cause unconsciousness and even death.
No studies are available about health effects in people exposed
to dibromochloromethane.
Animals exposed to high amounts of bromoform
or dibromochloromethane developed liver and kidney injuries.
Exposure to low levels of bromoform or dibromochloromethane
do not appear to seriously affect the brain, liver, or kidneys.
We do not know if bromoform or dibromochloromethane affect
fertility in humans, but studies in animals suggest that the
risk of doing so is low.
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How
likely are bromoform and dibromochloromethane to cause cancer? |
There is no conclusive evidence that
bromoform or dibromochloromethane cause cancer in humans because
no cancer studies of humans exposed exclusively to these chemicals
are available. Long-term oral exposure to bromoform produced
intestinal tumors in female rats and similar exposure to dibromochloromethane
produced liver tumors in male and female mice.
The International Agency for Research
on Cancer (IARC) concluded that bromoform and dibromochloromethane
are not classifiable as to human carcinogenicity. The EPA
classified bromoform as a probable human carcinogen and dibromochloromethane
as a possible human carcinogen.
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How
can bromoform and dibromochloromethane affect children? |
The only information regarding effects
of bromoform on the health of children is that from the early
1900s when this chemical was used as a sedative to treat children
with whooping cough. In some cases of overdosing with extremely
high doses, children appeared drowsy, then lifeless, just
before dying. A number of human studies examined the possible
association between drinking chlorinated water (containing
a number of chemicals including bromoform and dibromochloromethane)
and birth defects. These studies are not conclusive. Data
in animals exposed to these chemicals also are inadequate
to establish firm conclusions. We do not know whether children
are more susceptible to the effects of bromoform and dibromochloromethane
than adults.
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How
can families reduce the risks of exposure to bromoform and dibromochloromethane? |
- Families can reduce their exposure to bromoform and dibromochloromethane
from tap water by installing commercially available filter
systems at home.
- While bromoform is no longer used as a medicine, keeping
children away from, or supervising children with, chemicals
brought into the home, will reduce the potential for accidental
exposures.
- Families can reduce their exposure by taking shorter baths
or showers in water in which these chemicals are present
and opening bathroom windows or using ceiling ventilation
fans whenever possible.
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Is
there a medical test to determine whether I've been exposed
to bromoform and dibromochloromethane? |
Tests are available to measure levels
of these chemicals and their breakdown products in samples
of your blood, breath, or fat. These tests are not routinely
available in a doctor's office because they require special
equipment. Because bromoform and dibromochloromethane are
eliminated from the body fairly quickly, these tests are only
effective in detecting recent exposures (within 1 or 2 days
at the most).
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Has
the federal government made recommendations to protect human
health? |
The EPA recommends that drinking water
contain no more than 0.7 parts per million (0.7 ppm) of bromoform
and 0.7 ppm of dibromochloromethane.
The Occupational Safety and Health Administration
(OSHA) set a limit of 0.5 ppm for the level of bromoform in
workplace air during an 8-hour workday, 40-hour work week.
Because dibromochloromethane has such a limited use, OSHA
has not set limits of exposure for workplace air.
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 2003. Toxicological
Profile for Bromoform and Dibromochloromethane (Draft
for Public Comment). Atlanta, GA: U.S. Department of Public
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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