Chlorophenols herbicides

TCDD Manufacture of chlorophenols, herbicide contaminant, incineration of chemical wastes... 

In addition lo its use in making resins and adhesives, phenol is also the starting material for the synthesis of chlorinated phenols and the food preservatives BHT (butylated hvdroxytoiuene) and BHA (butylated bydroxyanisole). Penta-chlorophenol, a widely used wood preservative, is prepared by reaction of phenol with excess CI2- The herbicide 2,4-D (2,4-dichlorophenoxyacetjc acid) is prepared from 2,4-dichlorophenol, and the hospital antiseptic agent hexa-chlorophene is prepared from 2,4,5-trichlorophenol. 

PCDDs have been released into the environment in a number of different ways. Sometimes this has been due to the use of a pesticide that is contaminated with them. 2,4,5-T and related phenoxyalkanoic herbicides have been contaminated with them as a consequence of the interaction of chlorophenols used in the manufacturing... 

PCDFs are similar in many respects to PCDDs but have been less well studied, and will be mentioned only briefly here. Their chemical structure is shown in Figure 7.1. Like PCDDs, they can be formed by the interaction of chlorophenols, and are found in commercial preparations of chlorinated phenols and in products derived from phenols (e.g., 2,4,5-T and related phenoxyalkanoic herbicides). They are also present in commercial polychlorinated biphenyl (PCB) mixtures, and can be formed... 

Only the R(+) enantiomer of the herbicide 2-(2-methyl-4-chlorophenoxy)propionic acid was degraded (Tett et al. 1994), although cell extracts of Sphingomonas herbicidovorans grown with the R(-) or S -) enantiomer, respectively, transformed selectively the R -) or S(-) substrates to 2-methyl-4-chlorophenol (Nickel et al. 1997). 

Chlorinated phenols are used for the impregnation of timber and the production of phenoxyalkano-ate herbicides that are degraded by dioxygenation to chlorophenols. 

Used industrially to treat wool to prevent shrinking in the manufacture of rayon, rubber-base plastics, chlorophenol disinfectants, phosphate insecticides, heterocyclic fungicides and herbicides, and pharmaceuticals. 

PCDDs are present as trace impurities in some commercial herbicides and chlorophenols. They can be formed as a result of photochemical and thermal reactions in fly ash and other incineration products. Their presence in manufactured chemicals and industrial wastes is neither intentional nor desired. The chemical and environmental stability of PCDDs, coupled with their potential to accumulate in fat, has resulted in their detection throughout the global ecosystem. The number of chlorine atoms in PCDDs can vary between one and eight to produce up to 75 positional isomers. Some of these isomers are extremely toxic, while others are believed to be relatively innocuous. 

Kogevinas, M., H. Becher, T. Benn, PA. Bertazzi, P. Boffetta, H.B. Bueno-de-Mesquita, D. Coggon, D. Colin, D. Flesch-Janys, M. Fingerhut, L. Green, T. Kauppinen, M. Littorin, E. Lynge, J.D. Mathews, M. Neuberger, N. Pearce, and R. Saracci. 1997. Cancer mortality in workers exposed to phenoxy herbicides, chlorophenols, and dioxins. An expanded and updated international cohort study. Amer. Jour. Epidemiol. 145 1061-1075. 

Chlorophenols, manufacture of, 23 654 Chlorophenoxy acid herbicides, 73 304 (E) -(RS) -1 -(4-Chlorophenyl) -4,4-dimethyl-2-(lH- l,2,4-triazol-l-yl)-pent-l-en-3-ol, 73 47—48. See also 4-Chlorophenyl-4,4- dimethyltriazol pentenol 4-Chlorophenyl-4,4-dimethyltriazol pentenol, 73 40t, 47 48 Chlorophosphazenes, 19 55, 56 in silicone polymerization, 22 556... 

In non-saline sediments aliphatic and polyaromatic hydrocarbons, phthalate esters carboxylic acids, uronic acid aldoses chloroaliphatics haloaromatics chlorophenols chloroanisoles polychlorobiphenyls polychlorodibenzo-p-dioxins poychlorodibenzofurans various organosulphur compounds, chlorinated insecticides, organophosphorus insecticides mixtures of organic compounds triazine herbicides arsenic and organic compounds of mercury and tin. 

In sludge anionic and non-ionic surfactants carboxylic acids hhydroxybutyrate hydroxy valerate chloroaliphatic compounds chlorophenols polychlorobiphenyls 4-nitrophenol mixtures of organic compounds chlorinated insecticides, phenoxy acetic acid type herbicides and organotin compounds. 

Renberg [35] used an ion-exchange technique for the determination of chlorophenols and phenoxy acetic acid herbicides in soil. In this method the soil extracts are mixed with Sephadex QAE A-25 anion exchanger and the adsorbed materials are then eluted with a suitable solvent. The chlorinated phenols are converted into their methyl ethers and the chlorinated phenoxy acids into their methyl or 2-chloroethyl esters for gas chromatography. 

HMSO (1986) Chlorophenoxy acid herbicides, trichlorobenzoic acid, chlorophenols, triazines and glyphosate in water. HMSO, London... 

Synonyms AF 101 AI3-614378 Anduron Ansaron Bioron BRN 2215168 Caswell No. 410 CCRIS 1012 Cekiuron Crisuron Dailon DCMU DCMU 99 Dialer Dichlorfenidim 3-(3,4-Di-chlorophenol)-l,l-dimethylurea 3-(3,4-Dichlorophenyl)-l,l-dimethylurea A -(3,4-Dichloro-phenyl)-A,A-dimethylurea l,l-Dimethyl-3-(3,4-dichlorophenyl)urea Dion Direx 4L Diurex Diurol DMU DP hardener 95 Duran Durashield Dynex EINECS 206-354-4 EPA pesticide chemical code 035505 Farmco diuron Herbatox HW 920 Karmex Karmex diuron herbicide Karmex DW Krovar Lucenit Marmer NA 2767 NSC 8950 Seduron Sup r flo Telvar Telvar diuron weed killer UN 2767 Unidron Urox D USAF P-7 USAF XR-42 Vonduron. 

In the 19th century, various carbons were studied for their ability to decolorize solutions and adsorb compounds from gases and vapors. Commercial applications of activated carbon began early in the 20th century. Solutions containing phenols, acetic acid, herbicides, dyes, chlorophenols, cyanide and chromium have been successfully treated by carbon adsorption ( ). 

Such xenobiotics as aliphatic hydrocarbons and derivatives, chlorinated ahphatic compounds (methyl, ethyl, methylene, and ethylene chlorides), aromatic hydrocarbons and derivatives (benzene, toluene, phthalate, ethylbenzene, xylenes, and phenol), polycyclic aromatic hydrocarbons, halogenated aromatic compounds (chlorophenols, polychlorinated biphenyls, dioxins and relatives, DDT and relatives), AZO dyes, compounds with nitrogroups (explosive-contaminated waste and herbicides), and organophosphate wastes can be treated effectively by aerobic microorganisms. 

Johnson ES Review. Association between soft-tissue sarcomas, malignant lymphomas, and phenoxy herbicides/chlorophenols evidence from occupational cohort studies. Fundam Appl Toxicol 14 219-234, 1990... 

Organic compounds, aromatic solvents (benzene, toluene, nitrobenzenes, and xylene), chlorinated aromatics (PCBs, chlorobenzenes, chloronaphthalene, endrin, and toxaphene), phenols and chlorophenols (cresol, resorcinol, and nitrophe-nols), polynuclear aromatics (acenaphthene, benzopyrenes, naphthalene, and biphenyl), pesticides and herbicides (DDT, aldrin, chlordane, BHCs, heptachlor, carbofuran, atrazine, simazine, alachlor, and aldicarb), chlorinated... 

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