Consumer Factsheet on: DALAPON
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 Dalapon and how is it used?
Dalapon is a colorless liquid with an acrid odor sold as sodium or magnesium salt. Dalapon is a herbicide
used to control grasses in a wide variety of crops, including fruit trees, beans, coffee, corn, cotton and
peas. It is also registered for use in a number of non-crop applications such as lawns, drainage ditches,
along railroad tracks, and in industrial areas.
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:
Revenge
Alatex
Basfapon
Basinex
Crisapon
Dawpon-RAE
Ded-Weed
Dowpon
Gramevin
Kenapon
Liropon
Propon
Radapon
Unipon
S-1315
S-95
2,2-DPA
2,2-dichloro-proprionic acid
Why is Dalapon 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 MCLG for dalapon has been set at 0.2 parts per million (ppm) because EPA believes this level of
protection would not cause any of the potential health problems described below.

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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 also been set at 0.2 ppm 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: Dalapon is not known to cause any health problems when people are exposed to it at levels
above the MCL for relatively short periods of time.
Long-term: Dalapon has the potential to cause the following effects from a lifetime exposure at levels
above the MCL: increased kidney-to-body weight.
How much Dalapon is produced and released to the environment?
Dalapon is released directly to the environment in its use as a herbicide for the control of annual and
perennial grasses. Domestic production of dalapon in 1982 ranged between 7 and 9 million lbs. active
ingredient. In 1984, its use in California was reported as follows: Non-food use, 92.9% (mostly on rights of
way); main food crop treated was sugarbeet (6.7% of total).
What happens to Dalapon when it is released to the environment?
Dalapon leaches readily in soil, though in some soils, microbes may break it down fast enough to prevent
ground water contamination. Still, a persistence of six months has been observed in soils of various
forests and tree nurseries. Microbes will also degrade most of any releases to water. Accumulation in
aquatic life is not expected to be a problem.
How will Dalapon be Detected in and Removed from My Drinking
Water?
The regulation for dalapon 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 dalapon is
present above 1 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 dalapon so that it is consistently below that level. The following treatment methods
have been approved by EPA for removing dalapon: Granular activated charcoal.
How will I know if Dalapon is in my drinking water?
If the levels of dalapon exceed the MCL, 0.2 ppm, 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.

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Drinking Water Standards:
Mclg: 0.2 ppm
Mcl: 0.2 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 book's 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: EPA's 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

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