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 2,4-D and how is it used?
2,4-D is a colorless, odorless powder used as a herbicide for the control
of broad-leaf weeds in agriculture, and for control of woody plants
along roadsides, railways, and utilities rights of way. It has been most
widely used on such crops as wheat and corn, and on pasture and
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:
Brush Killer 64
Green Cross Weed-No-More 80
Red Devil Dry Weed Killer
Why is 2,4-D 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 2,4-D has been set at 70 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 70 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 2,4-D to potentially cause the following health
effects when people are exposed to it at levels above the MCL for
relatively short periods of time: nervous system damage.
Long-term: 2,4-D has the potential to cause the following effects
from a lifetime exposure at levels above the MCL: damage to the nervous
system, kidneys and liver.
How much 2,4-D is produced and released to the environment?
Production of 2,4-D was 45.1 million lbs in 1982. 1991 data indicates only
that production exceeded 5000 lbs. Major environmental releases of 2,4-D
are due to agricultural applications of systemic herbicides. It is also
released as a result of the production or disposal of 2,4-D or its
From 1987 to 1993, according to EPA's Toxic Chemical Release
Inventory, 2,4-D releases to land and water totalled over 116,000 lbs.
These releases were primarily from cane sugar-related industries (except
refineries). The largest releases occurred in Hawaii.
What happens to 2,4-D when it is released to the environment?
2,4-D is readily degraded by microbes in soil and water. Leaching to
ground water may occur in coarse-grained sandy soils with low organic
content or with very basic soils. In general little runoff occurs with
2,4-D or its amine salts. There is no evidence that bioconcentration of
2,4-D occurs through the food chain. This has been known from
large-scale monitoring studies of soils, foods, feedstuffs, wildlife,
human beings, and from other environmental cycling studies.
How will 2,4-D be detected in and removed from my drinking
The regulation for 2,4-D 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 2,4-D 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 2,4-D so
that it is consistently below that level. The following treatment
methods have been approved by EPA for removing 2,4-D: Granular activated
How will I know if 2,4-D is in my drinking water?
If the levels of 2,4-D exceed the MCL, 70 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: 70 ppb (parts per billion)
Mcl: 70 ppb
2,4-D Releases to Water and Land, 1987 to 1993 (in pounds):
|TOTALS (in pounds)
|Top Five States|
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.