75-99-0 Dalapon

Aliphatic-Garboxylics. There are only two herbicides present in this class, trichloroacetate [76-03-9] (TCA) and dalapon [75-99-0]. These are used primarily for the selective control of annual and perennial grass weeds in cropland and noncropland (2,299). Dalapon is also used as a selective aquatic herbicide (427). Dalapon and TCA are acidic in nature and are not strongly sorbed by sods. They are reported to be rapidly degraded in both sod and water by microbial processes (2,427). However, the breakdown of TCA occurs very slowly when incubated at 14—15°C in acidic sods (428). Timing not only accelerates this degradation but also increases the numbers of TCA-degrading bacteria. An HA has been issued for dalapon, but not TCA (269). 

Dalapon 0.2 0.2 Minor kidney changes Runoff from herbicide used on rights of way... 

Folmar, L.C. 1977. Acrolein, Dalapon, Dichlobenil, Diquat, and Endothal Bibliography of Toxicity to Aquatic Organisms. U.S. Fish Wildl. Serv. Tech. Paper 88. 16 pp. 

The recommended field application rates for terrestrial weed control usually range between 0.28 and 1.12 kg paraquat cation/ha (0.25 and 1.0 pounds/acre), between 0.56 and 2.24 kg paraquat dichloride/ha (0.5 and 2.0 pounds/acre) — both applied as an aerosol — and between 0.1 and 2.0 mg/L for aquatic weed control, although sensitive aquatic plants may be affected between 0.019 and 0.372 mg/L (Ross etal. 1979 Summers 1980 Bauer 1983 Dial and Bauer 1984). Paraquat is frequently used in combination with other herbicides (Fletcher 1974 Summers 1980). Water solutions of the dichloride salt, which usually contain 240 g/L, have been successfully mixed with 2,4-D, substituted ureas, dalapon, amitrol, and various triazines (Anonymous 1963, 1974). 

Frenock (sodium 2,2,3,3 tetra fluoro propionate) and Dalapon (sodium 2,2 Dichloropropionate)... 

Tsukioka et al. [187] determined these contact herbicides in soil by mass fragmentography. The method is based on the reaction of l-benzyl-3-p-polytriazene with an extract of Frenock and Dalapon from strongly acidified sample solutions to form benzylated species. In the analysis of soil samples, steam distillation was applied prior to extraction. Recoveries were >92% and precision <5%. 

Smith and Fitzpatrick [252] have also described a thin layer method for the detection in water and soil of herbicide residues, including Atrazine, Barban, Diuron, Linuron, Monuron, Simazine, Trifluralin, Bromoxynil, Dalapon, Dicamba, MCPB, Mecoprop, Dicloram, 2,4-D, 2,4-DB, Dichloroprop, 2,4,5-T, and 2,3,6-trichlorobenzoic acid. 

Herbicides 2,4-D, MCPA, Mecoprop, 4-(2,4-DB), TCA, Amitrole, Dalapon, Monuron, Chlorpropham, Endothal, Pyrazon, and DNOC. 

Some examples of dehalogenation of pesticides are shown in Fig. 6, indicating the microbial conversion of DDT, Lindane, and Dalapon to non-toxic products such as DDE, 2,3,4,5,6-penta-chloro-l-cyclohexene, and pyruvic acid, respectively. 

Dalapon by Liquid-Liquid Organic Compounds in Drinking... 

Determination of Haloacetic Acids and Dalapon in Drinking Water by Ion-Exchange LSE and GC widi ECD... 

Dalapon [75-99-0] Daphnia pulex EC50 (48-h) 1.04 Johnson and Finley, 1980... 

Chloroethyl vinyl ether, 2-Chlorophenol, Cyclohexene, Dalapon-sodium. Diallate. 1,1-Dichloroethane, 2,3-Dimethylamine, Dimethylbutane, 1,4-Dioxane, Ethylamine, Ethyl ether, Erhvl sulfide. 2-Heptanone, Metaldehvde. 2-Methvlbutane. 2-Methvl-2-butene. 2-Methyl phenol, Nitromethane, 4-Nitrophenol, 2-Nitropropane, 1-Octene, 2-Pentanone, Phenol, Toluene, Triethylamine, Vinyl chloride, o-Xylene, m-Xylene Acetamide, see Acetonitrile, Acrylamide, Acrylonitrile, Ethylamine... 

Methyl ferf-butvl ether. Thiram Carbon monoxide, see Acetaldehyde. Atrazine. Bromacil. Dalapon-sodium. Dieldrin, 1.4-Dioxane, Diuron, Formaldehyde, Formic acid, Malathion, Maleic anhydride. Methanol, Methyl chloride. Methylene chloride. Methyl iodide, 2-Methylpropene, fV-Nitrosodimethylamine, Oxalic acid, Phorate, Picloram, 2,4,5-T, TCDD, Tolnene, Triflnralin... 

Chlorinated dihydroxybenzenes, see Pentachlorophenol Chlorine, see Allidochlor. Anilazine. Bromacil. Chlordane, 2,4-D, Dalapon-sodium. p.p -DDT, Dicamba. Dieldrin, Diuron, Malathion, Monuron. Pentachloronitrobenzene. Picloram. Propachlor. 

Methyl cellosolve, see Methyl cellosolve acetate Methyl chloride, see Dalapon-sodium. 

Sodium chloride, see Carbon disulfide, see Dalapon-sodium... 

CASRN 127-20-8 molecular formula C3H3Cl2Na02 FW 164.95 Soil. Undergoes dechlorination and the liberation of carbon dioxide in soil. The residual activity is limited to approximately 3-4 months (Hartley and Kidd, 1987). The average half-life for dalapon-sodium in soil incubated in the laboratory under aerobic conditions was 15 d (Namdeo, 1972). 

Photolytic. Dalapon (free acid) is subject to photodegradation. When an aqueous solution (0.25 M) was irradiated with UV light at 253.7 nm at 49 °C, 70% degraded in 7 h. Pyruvic acid is formed which is subsequently decarboxylated to acetaldehyde, carbon dioxide, and small quantities of 1,1-dichloroethane (2-4%) and a water-insoluble polymer (Kenaga, 1974). The photolysis of an aqueous solution of dalapon (free acid) by UV light (X = 2537 A) yielded chloride ions, carbon dioxide, carbon monoxide, and methyl chloride at quantum yields of 0.29, 0.10, 0.02, and 0.02, respectively (Baxter and Johnston, 1968). 

Chemical/Physical. Slowly reacts with moisture at room temperature forming pyruvic acid (Frank and Demint, 1969 Kenaga, 1974), hydrochloric acid, and sodium chloride (Kenaga, 1974 Wolfe et al., 1990). The reported hydrolysis half-life of dalapon sodium salt at low concentrations (<1%) and temperatures less than 25 °C is several months (Kenaga, 1974). 

Products reported from the combustion of the free acid (dalapon) at 900 °C include carbon monoxide, carbon dioxide, chlorine, and hydrochloric acid (Kennedy et al, 1972a). 

Kenaga, E.E. Toxicological and residue data useful in the environmental safety evaluation of dalapon. Residue Rev, 53 109-151,1974. 

Namdeo, K.N. Persistence of dalapon in grassland soil. Plant and Soil, 31 445-448, 1972. 

Munch DJ, Munch JW, Pawlecki AM (1995) EPA Method 552.2. Determination of haloacetic acids and dalapon in drinking water by liquid-liquid extraction, derivatization and gas chromatography with electron capture detection. U.S. EPA, Cincinnati, OH, Available at http //www.caslab.com/EPA-Methods/PDF/552 2.pdf... 

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