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 1,2-Dichloropropane and how is it used?
1,2-Dichloropropane (1,2-DCP) is a colorless organic liquid with a
chloroform-like odor. The greatest use of 1,2-dichloropropane is in
making other organic chemicals. It is also used in making lead-free
gasoline, paper coating, soil fumigant for nematodes, and insecticide
for stored grain.
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 1,2-Dichloropropane 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 1,2-DCP 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 parts 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 1,2-DCP to potentially cause the following
health effects when people are exposed to it at levels above the MCL for
relatively short periods of time: damage to the liver, kidneys, adrenal
glands, bladder, and the gastrointestinal and respiratory tracts.
Long-term: 1,2-DCP has the potential to cause the following
effects from a lifetime exposure at levels above the MCL: the liver,
kidneys, bladder, gastrointestinal tract and the respiratory tract;
How much 1,2-Dichloropropane is produced and released to the environment?
Production of 1,2-DCP has decreased greatly since a 1980 report of 77
million lbs. Dow Chemical, the only listed producer, discontinued its
production in 1991. It may be released into the atmosphere or in
wastewater during its production or use as an intermediate in chemical
manufacture. There were also significant releases during its former use
as a soil fumigant. It may also leach from municipal landfills.
From 1987 to 1993, according to EPA's Toxic Chemical Release
Inventory, 1,2-dichloropropane releases to land and water totalled
nearly 104,000 lbs. These releases were primarily from chemical
industries. The largest releases occurred in New York.
What happens to 1,2-Dichloropropane when it is released to the environment?
1,2-DCP released to soil will largely evaporate. However, it has been
detected in groundwater. Releases to surface water will also evaporate,
and are not likely to accumulate in aquatic life.
How will 1,2-Dichloropropane be detected in and removed from my drinking water?
The regulation for 1,2-DCP 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 1,2-DCP 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 1,2-DCP so
that it is consistently below that level. The following treatment
methods have been approved by EPA for removing 1,2-DCP: Granular
activated charcoal in combination with Packed Tower Aeration.
How will I know if 1,2-Dichloropropane is in my drinking water?
If the levels of 1,2-DCP 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 ppm (parts per million)
1,2-Dichloropropane Releases to Water and Land, 1987 to 1993 (in pounds):
|TOTALS (in pounds)
Top Five States|
Gum, wood chemicals
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.