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 1,1,2-Trichloroethane and how is it used?
1,1,2-Trichloroethane (1,1,2-TCE) is an organic liquid with a
chloroform-like odor. It is only used to make vinylidene chloride which
is in turn used to make synthetic fibers and plastic wraps such as the
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 1,1,2-Trichloroethane 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 1,1,2-TCE has been set at 3 parts per billion (ppb)
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 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 1,1,2-TCE to potentially cause the following
health effects when people are exposed to it at levels above the MCL for
relatively short periods of time: irritation of gastrointestinal tract;
red or hemorrhaged lungs; pale liver.
Long-term: 1,1,2-TCE has the potential to cause the following
effects from a lifetime exposure at levels above the MCL: damage to
liver and kidneys; cancer.
How much 1,1,2-Trichloroethane is produced and released to the environment?
An estimated 124 million lbs. of 1,1,2-TCE was produced in the US during
1974, based on the manufacture of vinylidene chloride. It evaporates
during its use in the manufacture of vinylidene chloride and as a
solvent. It is also released in wastewater from these uses, and in
leachates and volatile emissions from landfills. The EPA estimates the
gross annual discharge of 1,1,2-TCE waste in the US to be 4 million lbs.
From 1987 to 1993, according to EPA's Toxic Chemical Release
Inventory, 1,1,2-TCE releases to land and water totalled over 30,000
lbs., of which about 98 percent was to water. These releases were
primarily from alkali and chlorine industries. The largest releases
occurred in Louisiana and Texas.
What happens to 1,1,2-Trichloroethane when it is released to the environment?
When released into water, 1,1,2-TCE should primarily evaporate. In soils,
it should partially evaporate and partially leach into the groundwater.
Its break down by microbes, if it occurs, is very slow. 1,1,2-TCE shows
little tendency to accumulate in aquatic life.
How will 1,1,2-Trichloroethane be detected in and removed from my drinking water?
The regulation for 1,1,2-TCE became effective in 1994. 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 1,1,2-TCE 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 1,1,2-TCE so
that it is consistently below that level. The following treatment
methods have been approved by EPA for removing 1,1,2-TCE: Granular
activated charcoal in combination with Packed Tower Aeration.
How will I know if 1,1,2-Trichloroethane is in my drinking water?
If the levels of 1,1,2-TCE 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.
Drinking Water Standards:
|Mclg: 3 ppb (parts per billion)
1,1,2-Trichloroethane Releases to Water and Land, 1987 to 1993 (in pounds):
|TOTALS (in pounds)
Top Five States*|
Meat packing plants
Blast furnaces, steelworks
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.