Also known as: Carbon tet, Perchloromethane, CCl4, Carbon
chloride, Tetrachloromethane, Perc
Chemical reference number (CAS): 56-23-5
What is carbon tetrachloride?
Carbon tetrachloride (Carbon tet) is a non-flammable colorless liquid with a heavy,
sweet odor. Before 1970, carbon tet was widely used as a cleaning fluid in home and
industry. Until 1986, the chemical was used as a grain fumigant. Carbon tet is still used
to manufacture propellants and other industrial chemicals. In homes, carbon tet may be
found in containers of spot remover or in fire extinguishers made before 1970.
Carbon tet evaporates quickly and is heavier than water. If carbon tet is spilled in
lakes or streams, most of it sinks. If spilled on soil, most of the chemical will
evaporate and the vapors will gather near the ground surface.
How are people exposed to carbon tetrachloride?
Drinking/Eating: People are most often exposed to carbon tet in the
environment by drinking contaminated groundwater. Carbon tet may contaminate groundwater
near locations where the chemical was improperly disposed. Since the compound is heavy,
some of the spilled liquid will sink through soil and enter groundwater. Carbon tet does
not move easily with groundwater. Plants do not take up or store carbon tet when they grow
in contaminated soil.
Touching: Carbon tet can be absorbed through the skin if a person
handles the chemical or contaminated soil, or bathes in contaminated water.
Breathing: Carbon tet evaporates easily from water. Therefore, a
person may be exposed to its vapors when they bathe, cook, or wash with contaminated
What standards regulate carbon tetrachloride?
Water: The state and federal drinking water standards for carbon tet
are set at 5 parts per billion (ppb). We suggest you stop drinking water that contains
more than 5 ppb of carbon tetrachloride (tet).
If levels of carbon tet are very high in your water, you may also need to avoid
washing, bathing or using the water for other purposes. Contact your local public health
agency for more information specific to your situation.
Air: No standards exist for regulating the amount of
carbon tet allowed in the air of homes. However, the Wisconsin Department of
Natural Resources (DNR) has set a residential indoor air action level for
carbon tet at 0.64 parts per billion by volume (ppbv). The action level is
considered to be protective of public health. Breathing carbon tet for a
lifetime at 0.64 ppbv is very unlikely to be harmful to people. If carbon tet
concentrations in air are above the action level, we recommend taking an
action to halt exposure.
Most people canít smell carbon tet until the
level exceeds 40,000 ppbv. If you can smell the chemical, the level is too high to be safe.
The Wisconsin Department of Natural Resources regulates the amount of
carbon tet that can be released into outdoor ambient air by industries.
Will exposure to carbon tetrachloride result in harmful health
People can experience the following symptoms immediately or shortly after breathing air
containing 100 ppm (100,000ppbv) of carbon tet for 30 minutes or drinking as little as 1 milliliter of
carbon tet (about an eye dropper full):
- Liver or kidney problems that may last many days after the exposure
- Blurred vision, dizziness, confusion and nerve damage
- Nausea and vomiting
- Irregular heartbeat and changes in blood pressure
The following health effects can occur after several years of exposure to carbon tet:
Cancer: Higher levels of liver cancer have been seen in people who
were exposed to carbon tet in the workplace. Carbon tet caused liver cancer in laboratory
Reproductive Effects: None have yet been noted in animals or humans.
Organ Systems: People exposed to high levels of carbon tet may
experience nerve damage, digestive disorders, weight loss, tiredness, confusion,
depression, loss of color vision and liver damage.
In general, chemicals affect the same organ systems in all people who are exposed. A
person's reaction depends on several thing, including individual health, heredity,
previous exposure to chemicals including medicines, and personal habits such as smoking or
drinking. Previous exposure to barbiturates may increase the effects of exposure.
Its also important to consider the length of exposure to the chemical; the amount
of chemical exposure; and whether the chemical was inhaled, touched, or eaten.
Can a medical test determine exposure to carbon tetrachloride?
Carbon tet can be measured in exhaled breath, blood, fat and other tissues. The tests
will confirm exposure but will not predict future health effects. People who are regularly
exposed to carbon tet may benefit from having their doctor monitor their blood count,
liver function and kidney function.
Seek medical advice if you have any symptoms that you think may be related to chemical
(P-44590 Revised 05/2012)
This fact sheet summarizes information about this chemical and is not a complete
listing of all possible effects. It does not refer to work exposure or emergency
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