1.1 What is HMX? |
1.2 What happens to HMX when it enters
the environment? |
1.3 How might I be exposed to HMX? |
1.4 How can HMX enter and leave my body? |
1.5 How can HMX affect my health? |
1.6 Is there a medical test to determine
whether I have been exposed to HMX? |
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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September 1997 |
Public Health Statement |
for |
HMX |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for HMX. 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 HMX and to emphasize the human health effects
that may result from exposure to it. The Environmental Protection
Agency (EPA) has identified 1,416 hazardous waste sites as
the most serious in the nation. These sites make up the National
Priorities List (NPL) and are the sites targeted for long-term
federal cleanup activities. HMX has been found in at least
10 of the sites on the NPL. However, the number of NPL sites
evaluated for HMX is not known. As EPA evaluates more sites,
the number of sites at which HMX is found may increase. This
information is important because exposure to HMX may cause
harmful health effects and because these sites are potential
or actual sources of human exposure to HMX.
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 HMX, 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.
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1.1
What is HMX? |
HMX, an acronym for High Melting
eXplosive, is also known as octogen and cyclotetramethylene-tetranitramine,
as well as by other names. It is a colorless solid that dissolves
slightly in water. Only a very small amount of HMX will evaporate
into the air; however, it can occur in air attached to suspended
particles or dust. The taste and smell of HMX are not known.
HMX is a manmade chemical and does not
occur naturally in the environment. It is made from other
chemicals known as hexamine, ammonium nitrate, nitric acid,
and acetic acid. HMX explodes violently at high temperatures
(534°F and above). Because of this property, HMX is used
in nuclear devices, plastic explosives, rocket fuels, and
burster chargers. A small amount of HMX is also formed in
making cyclotrimethylene-trinitramine (RDX), another explosive
similar in structure to HMX. The amount of HMX made and used
in the United States at present is not known, but it is believed
to be greater than 30 million pounds per year.
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1.2
What happens to HMX when it enters the environment? |
Most of the HMX that enters the environment
is released into waste water from places that make or use
HMX. A small amount of HMX can be released to the air as dust
or ash from facilities that burn waste contaminated with HMX.
Some HMX may be released to soil as a result of accidental
spills, the settling of HMX-containing dust particles from
the air, or the disposal of waste that contains HMX in landfills.
Dust particles containing HMX may be
carried by the wind for some distance. The distance depends
on a number of factors, including particle size, wind velocity,
and weather conditions. Eventually, these particles settle
to the earth, depositing on soil and surface waters. The length
of time that HMX remains in the air is not known.
In surface water, HMX does not evaporate
or bind to sediments to any large extent. Sunlight breaks
down most of the HMX in surface water into other compounds,
usually in a matter of days to weeks. The amount of time HMX
remains in surface water depends on how much light-absorbing
material is present. A small amount of HMX may also be broken
down by bacteria in the water. Some of the breakdown products
of HMX (nitrite, nitrate, formaldehyde, 1,1-dimethylhydrazine)
are also harmful to your health, although the amounts you
may be exposed to as a result of HMX in your drinking water
are not expected to be above trace levels.
Laboratory studies show that HMX is likely
to move from soil into groundwater, particularly in sandy
soils. For most soils, however, the movement of HMX into groundwater
is expected to be slow. Bacteria in the soil are not expected
to break down HMX to any large extent. Exactly how long HMX
will remain in the environment is not known; however, HMX
in soil and groundwater is expected to stay there for a long
time. It is not known if plants, fish, or animals living in
areas contaminated with HMX build up high levels of the chemical
in their tissues.
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1.3
How might I be exposed to HMX? |
There is no information on how often
you might be exposed to HMX in the environment or to how much.
Most people, however, probably won't be exposed to HMX from
the environment. People who work at facilities that make or
use HMX or RDX, such as military personnel, may be exposed.
These workers may be exposed by inhaling dusts that contain
HMX or by getting HMX-containing liquids on their skin. People
who live near facilities that make or use HMX, or near hazardous
waste sites that contain HMX, may also be exposed. For these
residents, exposure (if any) is most likely to occur from
contaminated groundwater. However, exposures to small amounts
of HMX from contaminated surface water, soil, and air are
also possible.
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1.4
How can HMX enter and leave my body? |
HMX can enter your body if you breathe
contaminated air, swallow contaminated water or soil, or get
substances that contain HMX on your skin. Very little is known
about how much and how fast HMX enters your body after you
are exposed.
Limited information from laboratory studies
in animals suggests that if you swallow HMX, only a small
amount (less than 5 percent) will be absorbed into your blood.
The rest of the HMX that is not absorbed leaves your body
in your feces, usually within a day or two after you are exposed.
Your blood carries the small amount of absorbed HMX to your
tissues. Animal studies suggest that the resulting concentrations
of HMX in your lungs, liver, heart, and kidneys may be slightly
higher than the concentrations in other tissues.
HMX does not remain in any of your tissues
for very long. Information from animal studies suggests that
your body can transform HMX into other compounds called metabolites.
At present, the identity and toxicity of these metabolites
are not known. Most of these metabolites leave your body in
your urine, usually within a few days after you are exposed.
Smaller amounts of these metabolites may be released in your
feces or in the air you breathe out.
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1.5
How can HMX affect my health? |
Information on the adverse health effects
of HMX is limited. In one human study, no adverse effects
were reported in workers exposed to HMX in air. However, the
concentrations of HMX in the workplace air were not reported
in this study, and only a small number of workers and effects
were investigated.
Studies in rats, mice, and rabbits indicate
that HMX may be harmful to your liver and central nervous
system if it is swallowed or gets on your skin. The lowest
dose producing any effects in animals was 100 milligrams per
kilogram of body weight per day (mg/kg/day) orally and 165
mg/kg/day on the skin. Limited evidence suggests that even
a single exposure to these dose levels harmed rabbits. The
mechanism by which HMX causes adverse effects on the liver
and nervous system is not understood.
The reproductive and developmental effects
of HMX have not been well studied in humans or animals. At
present, the information needed to determine if HMX causes
cancer is insufficient. Due to the lack of information, EPA
has determined that HMX is not classifiable as to its human
carcinogenicity.
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1.6
Is there a medical test to determine whether I have been exposed
to HMX? |
You can find out if you have been exposed
to HMX by having your blood, urine, or feces tested for HMX.
Since HMX is poorly absorbed after it is swallowed, the levels
of HMX in your blood and urine are likely to be lower than
those in your feces. For best results, tests for HMX should
be done within a few days after you are exposed. These tests
cannot be used to tell how much HMX you have been exposed
to or to predict whether or not you will experience adverse
health effects. These tests are not usually done in a doctor's
office, but require that the samples be sent to a laboratory
for testing.
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1.7
What recommendations has the federal government made to protect
human health? |
The federal government has made several
regulations and guidelines to protect human health. EPA recommends
that the concentration of HMX in an adult's drinking water
be less than 0.40 milligrams per liter (mg/L) for a lifetime
exposure. EPA regulates waste containing HMX as hazardous
and has set restrictions on its disposal in landfills. The
Department of State regulates the exportation of HMX, and
the Department of Transportation regulates its transportation.
The Bureau of Alcohol, Tobacco, and Firearms regulates the
importation, manufacture, distribution, and storage of HMX.
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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). 1997. Toxicological
profile for HMX. Atlanta, GA: U.S. Department of Health
and Human Services, Public Health Service.
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