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 rangelands.

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:

• "Agent White"
• Bladex-B
• Brush Killer 64
• Dicofur
• Dormon
• Ipaner
• Moxon
• Netagrone
• Pielik
• Verton 38
• Mota Maskros
• Silvaprop 1
• Agricorn D
• Acme LV4
• Croprider
• Fernesta
• Lawn-Keep
• Pennamine D
• Plantgard
• Tributon
• Weed-B-Gon
• Weedatul
• Agroxone
• Weedar
• Salvo
• Green Cross Weed-No-More 80
• Red Devil Dry Weed Killer
• Scott's 4XD
• Weed-Rhap LV40
• Weedone 100
• 2,4-Dichloro-phenoxyacetic acid

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 Goals.

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 by-products.

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 Water?

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 charcoal.

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.

Drinking Water Standards:

 
	Mclg:  70 ppb
	Mcl:   70 ppb

	2,4-D Releases to Water and Land, 
	1987 to 1993 (in pounds): 

	                    Water          Land

	TOTALS (in pounds)  3,444          113,358

	Top Five States

	HI                            73,679
	FL                            38,456
	MO                            4440
	MI                            822 
	TX                            800 

	Major Industries

	Cane sugar               99,886
	Agri. chems.             815
	Plastics, resins         696
	Misc. manufact.          400
	Gen. Chemical            126

	* Water/Land totals only include facilities with releases 
	greater than a certain amount - usually 1000 to 10,000 lbs.