1.1 What is hexachlorobutadiene? |
1.2 What happens to hexachlorobutadiene
when it enters the environment? |
1.3 How might I be exposed to hexachlorobutadiene? |
1.4 How can hexachlorobutadiene enter
and leave my body? |
1.5 How can hexachlorobutadiene affect
my health? |
1.6 Is there a medical test to determine
whether I have been exposed to hexachlorobutadiene? |
1.7 What recommendations has the federal
government made to protect human health? |
1.8 Where can I get more information? |
References |
|
|
|
May 1994 |
Public Health Statement |
for |
Hexachlorobutadiene |
|
|
|
This Public Health Statement is the
summary chapter from the Toxicological
Profile for hexachlorobutadiene. 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.
|
|
|
This Statement was prepared to give you
information about hexachlorobutadiene 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.
Hexachlorobutadiene has been found in at least 45 of the sites
on the NPL. However, the number of NPL sites evaluated for
hexachlorobutadiene is not known. As EPA evaluates more sites,
the number of sites at which hexachlorobutadiene is found
may increase. This information is important because exposure
to hexachlorobutadiene may cause harmful health effects and
because these sites are potential or actual sources of human
exposure to hexachlorobutadiene.
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 hexachlorobutadiene, 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, life-style, and state of health.
|
|
1.1
What is hexachlorobutadiene? |
Hexachlorobutadiene, also known as HCBD,
perchlorobutadiene, or Dolen-Pur, is a colorless liquid. It
does not evaporate or burn easily. Hexachlorobutadiene has
a turpentine-like odor. Most people will begin to smell a
mild to pungent odor if the compound is present in air at
1 part hexachlorobutadiene per million parts of air (ppm).
It is not known how it tastes or at what level people can
taste it.
Hexachlorobutadiene does not occur naturally
in the environment. It is formed during the processing of
other chemicals such as tetrachloroethylene, trichloroethylene,
and carbon tetrachloride. Hexachlorobutadiene is an intermediate
in the manufacture of rubber compounds and lubricants. It
is used as a fluid for gyroscopes, a heat transfer liquid,
or a hydraulic fluid. Outside of the United States it is used
to kill soil pests.
|
back to top |
|
1.2
What happens to hexachlorobutadiene when it enters the environment? |
Hexachlorobutadiene is released to the
environment in air, water, and soil, mainly as a result of
its disposal following industrial use. Most of the hexachlorobutadiene
wastes are destroyed by burning; some are released to the
air in this process. It is not known what happens to hexachlorobutadiene
after it enters the air. Based on the information we have
on similar compounds, it may be broken down by sunlight and
react with gases in the atmosphere. It is not known what chemicals
are formed by these reactions or if the compounds formed are
harmful. Based on the properties of similar compounds, one-half
of the hexachlorobutadiene in the air is expected to be broken
down to other chemicals within 60 days.
Hexachlorobutadiene may be released to
water during disposal of factory waste. It is not known what
happens to it in water or how long it remains there. Hexachlorobutadiene
that is present in water may pass into the air or soil in
small amounts. Small amounts of hexachlorobutadiene may be
released to soil as a result of disposal of industrial wastes
containing it. It is not known what happens to hexachlorobutadiene
after it contacts soil. Because hexachlorobutadiene binds
to most soils, it is expected to remain there for some time.
The hexachlorobutadiene present in sandy soils may move through
the soil to underground water. However, no information was
found on how much reaches the underground water or how long
it stays in the water. Hexachlorobutadiene can build up in
fish and shellfish, where waters are contaminated. It is not
known if hexachlorobutadiene builds up in plants.
|
back to top |
|
1.3
How might I be exposed to hexachlorobutadiene? |
You may be exposed to hexachlorobutadiene
by breathing contaminated air, eating contaminated food, drinking
contaminated water, or by direct skin contact with this chemical.
People working in the industrial facilities where hexachlorobutadiene
is formed or used may be exposed. Concentrations found in
outside air were 2–3 parts hexachlorobutadiene per trillion
parts of air (ppt). Levels were much higher in or near industrial
facilities where hexachlorobutadiene is formed or used. One
survey detected air concentrations ranging from 22 to 43,000
ppt in a production facility. No information is available
on how many workers are potentially exposed to hexachlorobutadiene.
Although hexachlorobutadiene is not very
soluble in water, small amounts may be found in some public
drinking water (less than 1 part hexachlorobutadiene per billion
parts water [ppb]). It may also be found in underground water
near hazardous waste sites. Hexachlorobutadiene has no agricultural
or food chemical uses in the United States.
Levels ranging from 0.1 to 4.7 milligrams
per kilogram have been found in fish and shellfish because
the compound is present in some surface water.
Exposure at waste sites is most likely
to occur from the landfill disposal of waste by-products originating
from chlorinated hydrocarbon manufacture.
|
back to top |
|
1.4
How can hexachlorobutadiene enter and leave my body? |
Hexachlorobutadiene may enter your body
through the lungs when you breathe air contaminated with it.
It also may enter your body if you drink water or eat food
contaminated with hexachlorobutadiene. With the exception
of fish and shellfish, however, hexachlorobutadiene has not
been found in food. The amount of hexachlorobutadiene that
enters your body by these routes depends on how much of the
chemical you eat or drink.
What happens to hexachlorobutadiene when
you breathe vapors of the compound is not known, but it most
likely moves across your lungs into your bloodstream. In animal
studies, most of the hexachlorobutadiene is changed by the
body into more toxic compounds. It is not known how rapidly
hexachlorobutadiene and its breakdown products are removed
from your body through your urine and feces. Some is expected
to remain in your body fat for long periods.
|
back to top |
|
1.5
How can hexachlorobutadiene affect my health? |
In one study of workers at a solvent
production plant who breathed hexachlorobutadiene for long
periods, the compound was shown to affect the function of
the liver. Because the workers were also exposed to other
solvents (carbon tetrachloride and perchloroethylene), it
is not certain if this effect was caused by hexachlorobutadiene
alone. Studies in mice showed that brief exposure to high
concentrations of hexachlorobutadiene irritate the nose. The
effects of breathing low levels of hexachlorobutadiene are
not known.
Ingestion of hexachlorobutadiene damaged
the kidneys of rats and mice and, to a lesser extent, the
liver of rats. These effects occurred after both short- and
long-term exposures at very low dose levels. Young rats were
affected more than adult rats. The kidneys of female rats
appeared to be affected more than those of males. On the other
hand, the liver of male rats was affected, but the liver of
female rats was not. It is not clear if the differences between
the sexes might be seen in humans. Kidney, brain, and liver
damage were also seen in rabbits after contact of their skin
with the compound for a short period.
Hexachlorobutadiene decreased fetal body
weight in rats, but did not affect fetal development or impair
their ability to produce offspring. The lungs, heart, brain,
blood, muscles, and skeleton in rats or mice were not damaged
after short- or long-term exposure.
Studies in rats indicate that hexachlorobutadiene
may increase the risk of kidney cancer if exposures occur
for long periods. The International Agency for Research on
Cancer (IARC) has determined that hexachlorobutadiene is not
classifiable as to its carcinogenicity in humans, but indicated
that there was limited evidence that hexachlorobutadiene was
carcinogenic in rats. EPA has determined that hexachlorobutadiene
is a possible human carcinogen.
|
back to top |
|
1.6
Is there a medical test to determine whether I have been exposed
to hexachlorobutadiene? |
Exposure to hexachlorobutadiene can be
determined by measuring the chemical or its breakdown products
in blood, urine, or fat. These tests are not usually performed
in most doctors' offices because special equipment is needed.
Samples can be collected and sent to special laboratories
to determine if you were exposed to hexachlorobutadiene. These
tests cannot determine how much of the chemical you were exposed
to or if adverse health effects will occur as a result of
the exposure.
|
back to top |
|
1.7
What recommendations has the federal government made to protect
human health? |
The federal government has developed
guidelines and standards to protect the public from excess
exposure to hexachlorobutadiene. EPA has recommended guidelines
on how much hexachlorobutadiene can be present in drinking
water for specific periods of time without causing adverse
health effects in humans. EPA recommends that exposures in
children should not exceed 0.3 milligrams per liter of water
(mg/L) for 10-day periods, or 0.1 mg/L for more than 7 years.
If adults are exposed for long periods (more than 7 years),
EPA recommends that exposure levels should not exceed 0.4
mg/L.
Hexachlorobutadiene has been named a
hazardous substance by EPA. If quantities equal to or greater
than 1 pound are released to the environment, the National
Response Center of the federal government must be notified
immediately.
The Occupational Safety and Health Administration
(OSHA) recommends that exposure to hexachlorobutadiene not
exceed 0.02 ppm for an 8-hour workday over a 40-hour workweek.
This limit is not enforced by the federal government, but
it is the law in at least 25 states.
The National Institute for Occupational
Safety and Health (NIOSH) classifies hexachlorobutadiene as
a potential occupational carcinogen. Because there is potential
for effects following contact of the chemical with the skin,
measures should be taken to minimize skin exposure.
|
back to top |
|
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
|
back to top |
|
References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1994. Toxicological
profile for hexachlorobutadiene. Atlanta, GA: U.S. Department
of Health and Human Services, Public Health Service.
|
back to top |
|
|
|