Also known as: 2,4-Dichlorophenoxyacetic acid, Weed-B-Gone, Acme,
Chemical reference number (CAS): 94-75-7
What is 2,4-D?
2,4-D is a popular weed killer used to control weeds like dandelions, clover, and
thistles. In its pure form, it is a colorless crystal that dissolves easily in water.
Nearly 60% of the 2,4-D sold in the United States is used on agricultural crops. The rest
is used on range and pasture land, lawns and turf, forests and in surface water.
In the home it may be found in common weed-and-feed products used on lawns. 2,4-D can
contaminate air during, and shortly after its applied. It can also be carried along
by rainwater. Soil may be contaminated with 2,4-D when the chemical is spilled or improperly disposed.
How are people exposed to 2,4-D?
Touching: People and their pets can be exposed to 2,4-D when they play
or walk on treated grass. Higher levels of exposure are possible during its manufacture,
distribution, or application.
Drinking/Eating: 2,4-D is rarely found in drinking water. People who
handle contaminated soil may be exposed when they touch their mouths or eat with dirty
Breathing: When 2,4-D is applied to lawns people can inhale mist or
dust that contains the chemical. It can be carried indoors on shoes or in windblown dust.
Once inside, 2,4-D breaks down slowly and can contaminate the indoor air.
Do standards exist for regulating 2,4-D?
Water: The state and federal drinking water standards for 2,4-D are
both set at 70 parts per billion (ppb). We suggest you stop drinking water that contains
more than 70 ppb of 2,4-D.
Air: No standards exist for the amount of 2,4-D allowed in the air of
homes. We use a formula to convert work place limits to suggested home limits. Based on
the formula, we recommend levels of 2,4-D in household air be no higher than 0.2 parts per
Will exposure to 2,4-D result in harmful health
The following symptoms may occur immediately or shortly after high level exposure to
- Severe burning in throat and chest
- Skin rash
- Stiffness of arms and legs
- Lack of coordination
- Loss of appetite
- Liver and kidney function changes
- Stupor and coma at very high levels
Health effects of concern after several years of exposure to 2,4-D:
Cancer: The EPA has not determined the ability of 2,4-D to cause
cancer. However, studies have found that exposure to 2,4-D appears to increase the risk of
lymphoma (a type of cancer affecting the immune system).
Reproductive Effects: It is not known whether exposure to 2,4-D is
safe during pregnancy. Some evidence suggests high-level exposure during pregnancy may
increase the risk of certain birth defects.
Organ Systems: Long term or high level exposure may result in kidney
and liver damage. Anemia has also been observed in laboratory animals.
In general, chemicals affect the same organ systems in all people who are exposed.
However, the seriousness of the effects may vary from person to person. A person's
reaction depends on several things, including individual health, heredity, previous
exposure to chemicals including medicines, and personal habits such as smoking or
Can a medical test determine exposure to 2,4-D?
Testing a persons urine for "chlorophenoxyacetic acid" can confirm a
recent exposure to 2,4-D, but cannot predict future symptoms. A medical evaluation after
high-level exposure may include tests of liver and kidney function and tests for anemia.
These tests indicate whether damage occurred, but may not be able to tell whether 2,4-D
caused the damage.
Seek medical advice if you have any symptoms that you think may be related to chemical
(P-44596 Revised 12/2010)
This fact sheet summarizes information about this chemical and is not a complete
listing of all possible effects. It does not refer to work exposure or emergency
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