Consumer Factsheet on: 1,2-DICHLOROETHYLENE
List of Contaminants
As part of the Drinking Water and Health pages, this fact
sheet is part of a larger publication:
National Primary Drinking Water Regulations
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).
What is 1,2-DCE and how is it used?
1,2-Dichloroethylene (1,2-DCE) is an odorless organic liquid that
has two slightly different forms, a "cis" form and a "trans" form.
Both the cis and trans forms - usually as a mixture - are used as
a solvent for waxes and resins; in the extraction of rubber; as a
refrigerant; in the manufacture of pharmaceuticals and artificial
pearls; in the extraction of oils and fats from fish and meat; and
in making other organics.
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:
1,2-DCE
Acetylene dichloride
Why is 1,2-DCE 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 Goals.
The MCLGs for 1,2-DCE have been set at 0.07 parts per million (ppm)
for the cis form, and 0.1 ppm for the trans form. 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 MCLs have also been set at 0.07 ppm for the cis form, and 0.1
ppm for the trans form. 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 cis- and trans-1,2-DCE to potentially
cause the following health effects when people are exposed to it at
levels above the MCL for relatively short periods of time: central
nervous system depression.
Long-term: Both cis- and trans-1,2-DCE have the potential to cause
liver, circulatory and nervous system damage from long-term
exposure at levels above the MCL. The trans form is approximately
twice as potent as the cis form in its ability to depress the
central nervous system.
How much 1,2-DCE is produced and released to the environment?
Releases to the environment are expected to be limited to
manufacturing plants in the Gulf Region of the United States. Since
cis-and trans-1,2-DCE are not listed chemicals in the Toxics
Release Inventory, data on releases during manufacture and handling
are not available.
Trans-1,2-dichloroethylene may be released to the environment in
air emissions and wastewater during its production and use as a
solvent and extractant, in organic synthesis, and in the
manufacture of perfumes, lacquers, and thermoplastics.
What happens to 1,2-DCE when it is released to the environment?
If 1,2-dichloroethylenes are released on soil, it should evaporate
and leach into the groundwater where it will break down very
slowly. If released to water, they will mainly evaporate. Neither
of the two forms of this contaminant are likely to accumulate in
aquatic life.
How will 1,2-DCE be Detected in and Removed from My Drinking Water?
The regulation for cis- and trans-1,2-DCE became effective in 1992.
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 cis- and trans-1,2-DCE 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 cis-
and trans-1,2-DCE so that it is consistently below that level. The
following treatment methods have been approved by EPA for removing
cis- and trans-1,2-DCE: Granular activated charcoal in combination
with Packed Tower Aeration.
How will I know if 1,2-DCE is in my drinking water?
If the levels of cis- and trans-1,2-DCE exceed their MCLs, 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: cis- 0.07 ppm; trans- 0.1 ppm
Mcl: cis- 0.07 ppm; trans- 0.1 ppm
Learn more about your drinking water!
EPA strongly encourages people to learn more about their drinking
water, and to support local efforts to protect and upgrade the
supply of safe drinking water. Your water bill or telephone books
government listings are a good starting point.
Your local water supplier can give you a list of the chemicals they
test for in your water, as well as how your water is treated.
Your state Department of Health/Environment is also a valuable
source of information.
For help in locating these agencies or for information on drinking
water in general, call: EPAs Safe Drinking Water Hotline: (800)
426-4791.
For additional information on the uses and releases of chemicals in
your state, contact the: Community Right-to-Know Hotline: (800) 424-9346.
List of Contaminants
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