This is a fact sheet about a chemical that may be found in some public or
private drinking water supplies. It may cause health problems if found
in amounts greater than the health standard set by the United States
Environmental Protection Agency (EPA).
What is Carbon Tetrachloride and how is it used?
Carbon tetrachloride is a clear heavy organic liquid with a sweet aromatic
odor similar to chloroform. Most of it is used to make
chlorofluorocarbon propellants and refrigerants, though this has been
declining steadily. Other uses have included: as dry cleaning agent and
fire extinguisher, in making nylon, as a solvent for rubber cement,
soaps, insecticides, etc.
The list of trade names given below may help you find out whether you
are using this chemical at home or work.
Trade Names and Synonyms:
Why is Carbon Tetrachloride being regulated?
In 1974, Congress passed the Safe Drinking Water Act. This law requires
EPA to determine safe levels of chemicals in drinking water which do or
may cause health problems. These non-enforceable levels, based solely on
possible health risks and exposure, are called Maximum Contaminant Level
The MCLG for carbon tetrachloride has been set at zero because EPA
believes this level of protection would not cause any of the potential
health problems described below.
Based on this MCLG, EPA has set an enforceable standard called a
Maximum Contaminant Level (MCL). MCLs are set as close to the MCLGs as
possible, considering the ability of public water systems to detect and
remove contaminants using suitable treatment technologies.
The MCL has been set at 5 part per billion (ppb) because EPA
believes, given present technology and resources, this is the lowest
level to which water systems can reasonably be required to remove this
contaminant should it occur in drinking water.
These drinking water standards and the regulations for ensuring
these standards are met, are called National Primary Drinking Water
Regulations. All public water supplies must abide by these regulations.
What are the health effects?
Short-term: EPA has found carbon tetrachloride to potentially cause the
following health effects when people are exposed to it at levels above
the MCL for relatively short periods of time: liver, kidney and lung
Long-term: Carbon tetrachloride has the potential to cause the
following effects from a lifetime exposure at levels above the MCL:
liver damage; cancer.
How much Carbon Tetrachloride is produced and released to the environment?
Production of carbon tetrachloride in 1988 was 761 million lbs Carbon
tetrachloride is released to land and water from landfills, in
wastewater from industries, from agricultural activities. From 1987 to
1993, according to the Toxic Release Inventory, carbon tetrachloride
releases to water and land totalled nearly 76,000 lbs. These releases
were primarily from chemical manufacturing industries. The largest
releases occurred in Texas.
What happens to Carbon Tetrachloride when it is released to the environment?
Carbon tetrachloride evaporates quickly from surface waters and soil. It
does not bind to soil and may leach into ground water. It has a low
potential to accumulate in aquatic life.
How will Carbon Tetrachloride be detected in and removed from my drinking
The regulation for carbon tetrachloride became effective in 1989. Between
1993 and 1995, EPA required your water supplier to collect water samples
every 3 months for one year and analyze them to find out if carbon
tetrachloride is present above 0.5 ppb. If it is present above this
level, the system must continue to monitor this contaminant.
If contaminant levels are found to be consistently above the MCL,
your water supplier must take steps to reduce the amount of carbon
tetrachloride so that it is consistently below that level. The following
treatment methods have been approved by EPA for removing carbon
tetrachloride : Granular activated charcoal in combination with Packed
How will I know if Carbon Tetrachloride is in my drinking water?
If the levels of carbon tetrachloride exceed the MCL, 5 ppb, the system
must notify the public via newspapers, radio, TV and other means.
Additional actions, such as providing alternative drinking water
supplies, may be required to prevent serious risks to public health.
This is a factsheet about a chemical that may be found in some
public or private drinking water supplies. It may cause health problems
if found in amounts greater than the health standard set by the United
States Environmental Protection Agency (EPA).
Drinking Water Standards:
Mcl: 5 ppb (parts per billion)
Carbon Tetrachloride Releases to Water and Land, 1987 to 1993 (in pounds):
|TOTALS (in pounds)
Top Five States*|
Misc. Indust. Organics
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water
* Water/Land totals only include facilities with releases greater
than a certain amount - usually 1000 to 10,000 lbs.