249 2,4-Dichlorophenoxyacetic acid 2,4-Dichlorophenoxyacetic acid (2,4-D) is a common systemic herbicide used in the control of broadleaf weeds. It is the most widely used herbicide in the world, and the third most commonly used in North America. 2,4-D is also an important synthetic auxin, often used in laboratories for plant research and as a supplement in plant cell culture media such as MS medium. (S685). 2,4-D can be formulated as emulsifiable concentrates, granules, soluble concentrate and solids, water-dispersible granules, and wettable powders. 2,4-D is used alone, but is commonly formulated with dicamba, mecoprop, mecoprop-p, MCPA, and clopyralid. 2,4-D was one of the ingredients in Agent Orange, the herbicide widely used during the Vietnam War. Though 2,4-D composed 50% of Agent Orange, the health effects of Agent Orange are related to dioxin contaminants generated during the production of Agent Orange – not 2,4-D itself. On August 8, 2007, the U.S. Environmental Protection Agency issued a ruling that stated that existing data do not support a link between human cancer and 2,4-D exposure. 94-75-7 1486 C8H6Cl2O3 219.969400 White to yellow powder. (L1190) 140.5°C 160 °C (0.4 mm Hg) 0.677 mg/mL at 25°C Oral (L1979); inhalation (L1979); dermal (L1979) 2,4-Dichlorophenoxyacetic acid is a strong oxidant and is known to cause lipid peroxidation and the generation of free radicals that can modify lipids and proteins. It is also known to inhibit glutathione S transferase which leads to a depletion of ATP, NADPH and glutathione (A3122, A3123). These actions can cause cell toxicity and apopotosis among metabolically active cells. Some of the endocrine effects of 2,4-D may be mediated by the 2,4-D mediated displacement of sex hormones from the sex hormone binding globulin or the 2,4-D mediated blocking or OAT6 transport proteins that are needed for the transport of functional organic ions and dicarboxylates (including estrone sulfate). Metabolism of 2,4-D is minimal in humans, with nearly all of it excreted unchanged as the parent compound. In particular, 2,4-D is rapidly excreted from the body, primarily in the urine. Much of the compound appears to be eliminated unchanged, although some 2,4-D is eliminated from the body as a conjugate. 2,4-D is metabolized to 2,4-dichlorophenol (2,4-DCP) by cytochrome P450 3A4 (CYP 3A4), the major form of monooxygenase enzyme in the human liver. LD50: 1400 mg/kg (Dermal, Rabbit) (T14) LD50: 469 mg/kg (Oral, Guinea pig) LD50: 639 mg/kg (Oral, Rat) (L1982) LD50: 138 mg/kg (Oral, Mouse) (L1982) 80-800 mg/kg (Oral) (A5641) 2B, possibly carcinogenic to humans. (L135) 2,4-D is is an agrochemical - a substance that is used in agriculture or horticulture. It is a broadleaf herbicide, which when sprayed or dusted on plants causes its leaves to fall off, and functions as a synthetic auxin. 2,4-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. All forms of 2,4-D are considered low in toxicity when absorbed via skin or via inhalation. The acid and salt forms of 2,4-D are highly toxic to eye tissue. Long term chronic exposure to 2,4-D has been linked to non-Hodgkins lymphoma and Parkinson’s disease but these are epidemiological associations only. 2,4-D is also reported to have negative effects on the endocrine system (specifically the thyroid and gonads) and immune system. 2,4-D displaces sex hormones from the protein (sex hormone binding globulin) that normally transports these hormones in the blood. 2,4-D reduces the activity of several proteins important to immune system function. Researchers at NIOSH have demonstrated a decreased production of cells responsible for making antibodies in mice bone marrow, in addition to decreased T-cells, produced in the thymus. Symptoms of acute oral exposure include vomiting, diarrhea, headache, confusion, aggressive or bizarre behavior, hypotension and muscle twitching. Skeletal muscle injury and renal failure may also occur. Prolonged dermal exposure may include skin irritation, whereas prolonged inhalation exposure may lead to coughing and burning sensations in the upper respiratory tract and chest. The general treatment of acute chlorophenoxy herbicide poisoning consists of decontamination of the gastrointestinal tract, resuscitation and supportive care. For severe, acute oral poisoning by 2,4-D forced alkaline diuresis appears to be most effective (A7734). Forced alkaline diuresis is often used to increase the excretion of acidic drugs like salicylates and phenobarbitone. For forced alkaline diuresis, a diuretic like furosemide is given intravenously and sodium bicarbonate is added to the infusion fluid to make blood and, in turn, urine alkaline. Potassium replacement becomes of utmost importance during the process because potassium is usually lost in urine. If blood levels of potassium are depleted below normal levels, then hypokalemia occurs, which promotes bicarbonate ion retention and prevents bicarbonate excretion, thus interfering with the alkalinization of the urine. 2009-03-06T18:58:22Z 2014-12-24T20:21:24Z http://en.wikipedia.org/wiki/2,4-dichlorophenoxyacetic_acid C03664 28854 CPD-9009 D015084 2,4-Dichlorophenoxyacetic acid CFA 447 true OC(=O)COC1=C(Cl)C=C(Cl)C=C1 C8H6Cl2O3 InChI=1S/C8H6Cl2O3/c9-5-1-2-7(6(10)3-5)13-4-8(11)12/h1-3H,4H2,(H,11,12) InChIKey=OVSKIKFHRZPJSS-UHFFFAOYSA-N 221.037 219.969399472 Exogenous Solid 2.81 HMDB41797 CHEMBL367623 1441 Robert Pokorny New Compounds. Some Chlorophenoxyacetic Acids J. Am. Chem. Soc., 1941, 63 (6), pp 1768–1768