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-Dichloroethylene and how is it used?
1,1-Dichloroethylene (1,1-DCE) is an organic liquid with a mild,
sweet, chloroform-like odor. Virtually all of it is used in making
adhesives, synthetic fibers, refrigerants, food packaging and coating
resins such as the saran types.
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-Dichloroethylene 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-DCE has been set at 7 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 7 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-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: liver damage.
Long-term: 1,1-DCE has the potential to cause the following
effects from a lifetime exposure at levels above the MCL: liver and
kidney damage, as well as toxicity to the developing fetus; cancer.
How much 1,1-Dichloroethylene is produced and released to the
An estimated 90,700 tons/yr of 1,1-DCE were produced in the USA during the
early 1980s. It may be released by evaporation or in wastewater during
its production and use in the manufacture of plastic wrap, adhesives,
and synthetic fiber. It may also form in groundwater that has been
contaminated by similar solvents.
From 1987 to 1993, according to the Toxics Release Inventory,
releases to water and land totalled over 11,500 lbs. These releases were
primarily from facilities which make plastics materials/resins. The
largest releases occurred in Kentucky.
What happens to 1,1-Dichloroethylene when it is released to the
Releases to water will primarily be lost to the atmosphere through
evaporation. 1,1-DCE will evaporate from soil and will leach into the
groundwater where its fate is unknown, but degradation is expected to be
slow. Its tendency to accumulate in aquatic life is unknown but expected
to be minor
How will 1,1-Dichloroethylene be detected in and removed from my
The regulation for 1,1-DCE 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 1,1-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 1,1-DCE so
that it is consistently below that level. The following treatment
methods have been approved by EPA for removing 1,1-DCE: Granular
activated charcoal in combination with Packed Tower Aeration.
How will I know if 1,1-Dichloroethylene is in my drinking water?
If the levels of 1,1-DCE exceed the MCL, 7 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:
|Mclg: 7 ppb (parts per billion)
1,1-Dichloroethylene Releases to Water and Land, 1987 to 1993 (in
|Top Three States*|
|Plastics materials, resins
* Water/Land totals only include facilities with releases greater
than a certain amount - usually 1000 to 10,000 lbs.
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water