Biocides pentachlorophenol

POLYMERIC BIOCIDES. PENTACHLOROPHENOL-FUNCTIONALISED VARNISH RESINS... 

The production of hydroxyl radicals by tetra-chlorohydroquinone, a major metabolite of the widely used biocide pentachlorophenol in the presence of H2O2 was markedly inhibited by hydroxyl radical scavenging agents dimethyl sidphoxide and ethanol, as well as by tetrachlorohydroquinone radical scavengers desferrioxamine and other hy-droxamic acids (Zhu et al. 2000). In contrast, their production was not affected by the nonhydroxym-ate iron chelators, diethylenetriaminepentaacetic acid, bathophenanthroline disulphonic acid, and phytic acid, as well as the copper-specific chelator bathocuprione disulphonic acid. 

In addition to these primary sources, the contamination of the food chain may create various waste products, such as industrial compost, landfill materials, sewage sludges, contaminated industrial products, for example herbicides based on 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), technical PCB mixtures, biocide pentachlorophenol (PCP) and its salts. 

The trend from heavy metal and phenolic based biocides, e.g. mercury and pentachlorophenol types, to more environmentally acceptable but less persistent organic types, requires more attention to plant hygiene (Figure 6, Briggs, 1980). 

Best available technology economically achievable (BAT) guidelines for the control of nonconventional and toxic pollutants (trichlorophenol and pentachlorophenol, which are chemicals used as biocides)... 

Slimicide and biocide toxic pollutants containing pentachlorophenol are used at mills in the pulp, paper, and paperboard industry. Initially, pentachlorophenol was used as a replacement for heavy metal salts, particularly mercuric types. Trichlorophenols are also used because of their availability as a byproduct from the manufacture of certain herbicides. Formulations containing organo-bromides and organo-sulfur compounds are also being used. Substitution of alternative slimicide and biocide formulations can lead to the virtual elimination of pentachlorophenol and trichlorophenol from these sources. 

Phenol has a wide range of uses, including in the preparation of phenolic and epoxy resins (bisphenol-A), nylon-6 (caprolactam), 2,4-D, selective solvents for refining lubricating oils, adipic acid, salicylic acid, phenolphthalein, pentachlorophenol and other derivatives in germicidal paints as a laboratory reagent and in dyes and indicators and as a slimicide, biocide and general disinfectant (Lewis, 1993). The world demand for phenol by use in 1993 was reported as (%) phenolic resins, 35 bisphenol-A, 30 caprolactam, 15 alkylphenols, 7 aniline, 5 and others, 8 (Wallace, 1996). 

Biocides most often found in the indoor environment are chlorinated hydrocarbons like chlordane, DDT, dieldrin, lindane, heptachlor and methoxychlor, pyrethroids like cyfluthrin, cypermethrin, and permethrin, organophosphates like chlorpyrifos, diazinon, dichlorvos, isofenfos, and malathion, carbamates like ben-diocarb, carbaryl and propoxur and chlorophenols like pentachlorophenol (PCP), chlorocresol (4-chloro-3-methylphenol) and o-phenylphenol. Residues formed in house dust may vary in different countries (Butte, 2003), but biocides like chlorpyrifos, DDT, methoxychlor, permethrin, pentchlorophenol and propoxur seem to be the active compounds in biocide formulations even in different continents, as they are found equally in house dust samples form Germany and the USA (Becker et al., 2002 Butte, 2003 Camann, Colt and Zuniga, 2002). Concentrations of biocides in house dust are mostly in the milligram per kilogram range, they seldom exceed a microgram per cubic meter in indoor air. 

Figure 12.3 Time periods of possible application of biocides in museums (MCN monochloronaphthalene DCN dichloronaphthalene PCP pentachlorophenol DDT ...

Samples may also contain microorganisms, which may degrade the sample biologically. Extreme pH (high or low) and low temperature can minimize microbial degradation. Adding biocides such as mercuric chloride or pentachlorophenol can also kill the microbes. 

The majority of phenols, especially those containing chlorine, are too phytotoxic to permit their use as agricultural fungicides. They are widely used as industrial fungicides. Cresols contribute to the fungicidal action of creosote which is used as a timber preservative. Pentachlorophenol, another chlorinated phenol, and its esters are widely used as industrial biocides for the protection of such materials as wood and textiles. 

Many of the biocides presently used in wood preservation preparations, e.g. pentachlorophenol (PCP), linane (y-HCH), creosote, and copper chromium arsenic-salts... 

The long-term effectiveness of TBTMA as a biocide has been confirmed (23). The deterioration of southern pine wood specimens impregnated with TBTMA has been compared with specimens that were treated with pentachlorophenol methacrylate (PGPMA) or pen-tabromophenol methacrylate (PGBMA). The three esters were incorporated as the copolymer by in situ copolymerization with methyl methacrylate (MMA) at different molar ratios of the comonomers. 

Detoxification involves a chemical change to a molecule. In equation 3, pentachlorophenol (PCP), a powerful biocide used in wood preservative, undergoes O-methylation. This transforms PCP to a far less toxic compound pentachloroanisole. Detoxification by one group of microorganisms often allows other organisms to continue biodegradation. 

Pentachlorophenol is an effective broad-spectrum biocide widely used as a wood preservative. Two-year carcinogenicity studies had been conducted in B6C3F1 mice and similar studies were planned in Fischer 344 rats. To aid in future comparison of the results of the toxicology studies in both species and to provide information for dose-response relationships, toxicokinetic evaluations were conducted. In singlc-and multiple-exposure studies the toxicokinetics of... 

Over the past few years several biocides have been converted to monomers containing ester, amide, or ether functions which bind the biocide and the polymerization of these monomers was studied.12-16 fhe biocides examined included pentachlorophenol, 1,12-16 8-hydroxyquinoline,2,12,14-16 3 4, 5-tribromosalicy-lanilide,3,12, 14-16 o-benzyl-p-chlorophenol,4,14-16 salicy-lanilide,5,12 2-(4 -thiazoyl)benzimidazole,6,12 and 2-mercapto-pyridine-N-oxide, 7. 

Pentachlorophenol was chosen because it is a broad spectrum biocide widely used as a wood preservative and as a slime control agent.17-20 8-Hydroxyquinoline had been used as a fungicide before 1900 and is thought to function by chelating metal ions.21 23 Tribromosalicylanilide is an active biocide with low dermatological effects to humans.24-26 jj-g biocidal effects vary upon the addition of surfactants to its medium. o-... 

Latex 13 Incorporates both the acrylate, 8, and extended chain acrylate, 10, of pentachlorophenol. Thus, two different releasing groups attach the same biocide. Latex 14 Incorporates the acrylates of both pentachlorophenol and tribromosalicylanilide (I.e. 8 and 14) so that It can release two different biocides. 

The question of whether or not a polymer-anchored biocide can be active against microorganism growth was first tested by comparing the minimum inhibitory concentrations (MIC) of pentachlorophenol, its acrylate, 8, and the homopolymer of pentachlorophenyl acrylate 8. An agar dilution method was used. To a sterilized agar, a solution of the compound to be tested was added in the appropriate amount to make final concentrations of 1000, 500, 250, 100, 50, and 10 ppm. Following inoculation, the... 

Pentachlorophenol, a biocide, was fixed to a fatty alkyd resin and to an epoxy ester of soya oil fatty acids to yield a good coat-forming functionalised resin. 28 refs. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology. 

Pesticides with this mode of action include such old products as the dinitrophenols (dinitroorthocreosol [DNOC], dinoterb, and dinoseb) and other phenols such as pentachlorophenol and ioxynil. DNOC is a biocide useful against mites, insects, weeds, and fungi. The mammalian toxicity is rather high, with a rat oral LD50 (lethal dose in 50% of the population) of 25 to 40 mg/kg of the sodium salt. The typical symptom is fever, which is... 

Pentachlorophenol, PCP, is a highly effective biocide developed in 1935 by the Monsanto Chemical Company and used today in the Asian region primarily as a wood preservative. 

PCDDs/PCDFs Pentachlorophenol and other biocides in wood preservatives, textiles, leather Products containing PCBs Open fires in the presence of halogenated materials... 

Especially for higher concentrations of biocides in air, impinging methods are an alternative. Pentachlorophenol concentrations can be analyzed after passing the air through an aqueous alkaline solution. A similar method has been reported for carbaryl and baygon. These biocides were absorbed in a sodium hydroxide solution and the hydrolysis products coupled to p-aminoacetophenol. The resulting dye could be spectrophotometrically quantified at A = 580 or 555 nm with a detection limit of about... 

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