![]() Collectively, this causes cells to divide and the plant to grow uncontrollably, resulting in tissue damage and ultimately death.Ģ,4-D is reported to have negative effects on the endocrine system (specifically the thyroid and gonads) and immune system. From the meristems, 2,4-D acts as an auxin and increases the following three characteristics of the plant: plasticity of cell walls, amount of proteins being made, and ethylene production. ![]() 2,4-D is absorbed by the leaves of the plant and eventually enters the meristems of the plant. In plants, 2,4-D affects double-leaf seeds rather than single-leaf seeds, explaining why it is selective against broadleaf plants. A single dose of 2,4-D is excreted within a few days, mainly through the urine, but also in the bile and feces (International Programme on Chemical Safety, WHO Geneva, 1984). Once absorbed in the body, there is little evidence that 2,4-D is accumulated and only a small percentage is transformed in 2,4-D conjugates with sugars or amino acids. In humans, 2,4-D exposure can occur through inhalation, skin absorption, ingestion, and skin/eye contact. Though 2,4-D composed 50% of Agent Orange, the health effects of Agent Orange are related to the dioxin (EXOTOXNET, 1996). 2,4,5-T becomes contaminated with dioxin during its production. It was roughly a mixture of two chemicals, 2,4-D and 2,4,5-T. The herbicide and defoliant Agent Orange, by far the most toxic of the Army's Rainbow Herbicides, was widely used in the Vietnam War to destroy foliage in an effort to expose the enemy by destroying their cover. 2,4-D's low cost has led to continued usage today and it remains one of the most commonly used Herbicides in the world. It is easy and inexpensive to manufacture, and it kills many broadleaf plants while leaving grasses largely unaffected (although high doses of 2,4-D at crucial growth periods can harm grass crops such as maize or cereals). 2,4-D was developed by a British team during World War II and first saw widespread production and use in the late 1940s. HistoryĢ,4-D was developed during World War II at British Rothamsted Experimental Station by Judah Hirsch Quastel and sold commercially in 1946. Approximately two-thirds of use is for agricultural purposes and one-third is for residential purposes. 2,4-D is used alone, but is commonly formulated with dicamba, mecoprop, mecoprop-p, MCPA, and clopyralid (EPA RED FACTS, 2005).Ģ,4-D is a High Production Volume (HPV) chemical with annual usage around 46 million pounds, making it one of the most widely used Herbicides in the world (#Scorecard and #EPA RED FACTS, 2005). In the US 2,4-D is used predominantly in the Midwest, Great Plains, and Northwest (EPA RED FACTS, 2005).Ģ,4-D is commonly found in lawn care products wheat, corn, and other grass family herbicides forestry products treatments for roadside weeds and aquatic weed control products (NPTN).Ģ,4-D can be sprayed from many different applicators such as fixed-wing aircraft, truck-mounted sprayers, and backpack sprayers (EPA RED Decision, 2005).Ģ,4-D can be formulated as emulsifiable concentrates, granules, soluble concentrate and solids, water-dispersable granules, and wettable powders. On average, 4.6 million pounds are used annually: 66% on agriculture, 23% on pasture/ rangeland, and 11% by homeowners. UseĢ,4-D is a post-emergence systemic herbicide used widely for selective control of broadleaf plants in a variety of food, forest, aquatic, and residential sites. Despite the short half-life, low levels of 2,4-D have been detected in groundwater supplies in at least 5 states in the United States. ![]() The most common form is the acid form, which is the subject of the majority of toxicity tests (Journal of Pesticide Reform, 2005).Ģ,4-D has a chemical half-life in soil between seven and ten days, depending on temperature, moisture, sterility, nutrient composition, and oxygenation of the soil. In addition to 2,4-D itself, there are eight salts and esters of 2,4-D. 2,4-D is a strong oxidizer and is a non-combustible solid however, it can be dissolved in flammable liquids (CDC NIOSH 2005.) 2,4-D is chemically classified as a chlorophenoxy herbicide and is an odorless, crystalline powder that is colorless or white to yellow. ![]()
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