Solvent, solvents trichloroethylene

Oxidation. 1,1,1-Trichloroethane is stable to oxidation when compared to olefinic chlorinated solvents like trichloroethylene and tetrachloroethylene. Use of a 48-h accelerated oxidation test gave no hydrogen chloride, whereas trichloroethylene gave 0.4 wt % HCl and tetrachloroethylene gave 0.6 wt % HCl (22). 

Respiratory Effects. One study suggested increased respiratory disorders (asthma, bronchitis, pneumonia) in children with chronic exposure to a solvent-contaminated water supply (Byers et al. 1988). Two municipal wells in eastern Woburn, Massachusetts, were found to contain several solvents including trichloroethylene (267 ppb) and tetrachloroethylene (21 ppb). The increased susceptibility to infection may be secondary to effects on the immune system. Accurate chemical-specific exposure levels for individuals could not be determined because the water distribution system was designed to use water from different wells at different rates and times. Other limitations of this study are described in Section 2.2.2.8. 

A study of three Michigan communities exposed to chlorinated solvents including trichloroethylene (up to 14,890 ppb) in contaminated drinking water found no increase in congenital defects (Freni and Bloomer 1988). The size of the cohort, however, was smaller than that of other studies, making statistically significant associations more difficult to identify. 

Trichloroethylene is an excellent extraction solvent for greases, oils, fats, waxes, and tars and is used by the textile processing industry to scour cotton, wool, and other fabrics (lARC 1979 Kuney 1986 Verschueren 1983). The textile industry also uses trichloroethylene as a solvent in waterless dying and finishing operations (McNeill 1979). As a general solvent or as a component of solvent blends, trichloroethylene is used with adhesives, lubricants, paints, varnishes, paint strippers, pesticides, and cold metal cleaners (Hawley 1981 lARC 1979 McNeill 1979). 

Waller PA, Clauw D, Cupps T, et al. 1994. Fascitis (not scleroderma) following prolonged exposure to an organic-solvent (trichloroethylene). J Rheumatol 21 1567-1570. 

Several epidemiologic studies of scleroderma, undifferentiated connective tissue disease, and multiple sclerosis suggest modest associations with any solvents or with organic or chlorinated solvents Trichloroethylene, paint removers, and mineral spirits are some of the specific solvents implicated in these studies. Mechanistic research in MRL +/+ lupus mice. 

Solvents (trichloroethylene or methylene chloride, for example), pure or with dissolved PPE. 

The large volume solvents, trichloroethylene and perchloroethylene, are still chiefly made from acetylene, but appreciable amounts of the former are derived from ethylene. The competitive situation between these source materials runs through the whole chlorinated hydrocarbon picture, and extends on to other compound classes as well—for example, acrylonitrile is just on the threshold of a severalfold expansion, as demand grows for synthetic fibers based thereon. Acrylonitrile can be made either from ethylene oxide and hydrogen cyanide, from acetylene and hydrogen cyanide, or from allylamines. The ethylene oxide route is reported to be the only one in current commercial use, but new facilities now under construction will involve the addition of hydrogen cyanide to acetylene (27). 

Many of the bisbenzocyclobutene polymers are relatively unaffected by organic solvents and aqueous media. In Table 11 are shown some of the results which were obtained in a solvent pick-up study carried out on the bisbenzocyclobutene polyester 40 [2]. Of all of the solvents, only trichloroethylene and methyl ethyl ketone were absorbed to any significant extent at 70 °C over the four-week course of the experiment. None of the polymer samples dissolved in the solvents that were tested and only a slight swelling was observed with those liquids which were significantly absorbed. The small effect of aqueous sodium hydroxide on the bisbenzocyclobutene polyester is deserving of note since a control sample of a commercial polyimide (Vespel ) dissolved completely in two days under the conditions of this test. 

Many of the private laboratories offer screening for heavy metals (including lead, mercury, cadmium, arsenic, aluminum, and nickel) and other chemicals, such as PCBs, chlorinated solvents, trichloroethylene, and pesticides. One such laboratory advertised testing for nearly 70 chemicals. Occupational screening was also offered at some of the laboratories. For many laboratories, people may order test and screening kits over the Internet, by fax, or by telephone. A person can send in a blood, urine, or hair sample for analysis. In some cases, a physician s signature is required to have the sample tested. 

As shown in Figure 1.17, there are three possible dichloroethylene compounds, all clear, colorless liquids. Vinylidene chloride forms a copolymer with vinyl chloride used in some kinds of coating materials. The geometrically isomeric 1,2-dichloroethylenes are used as organic synthesis intermediates and as solvents. Trichloroethylene is a clear, colorless, nonflammable, volatile liquid. It is an excellent degreasing and dry-cleaning solvent and has been used as a household solvent and for food extraction (for example, in decaffeination of coffee). Colorless, nonflammable liquid tetrachloroethylene has properties and uses similar to those of trichloroethylene. Hexachloro-butadiene, a colorless liquid with an odor somewhat like that of turpentine, is used as a solvent for higher hydrocarbons and elastomers, as a hydraulic fluid, in transformers, and for heat transfer. 

Caffeine has been isolated from waste tea and from the decaffeiniza-tion of coffee by extraction at 70°C, using rotating countercurrent drums and an organic solvent, frequently trichloroethylene. The solvent is drained off, and the beans steamed to remove residual solvent. The extraction solvent is evaporated, and the caffeine is hot-water-extracted from the wax, decolorized with carbon, and recrystallized. 

Many groundwaters are contaminated with the cleaning solvents trichloroethylene (TCE) and perchloroethylene (PCE). They are two of the most common organochlorine compounds found in Superfund sites. Radiation-induced decomposition of TCE in aqueous solutions has been the subject of several recent studies [15-20]. In most of the referenced studies, the complete destruction of TCE was observed. Dechlorination by a combination of oxidative and reductive radiolysis was stoichiometric. Gehringer et al. [15] and Proksch et al. [18] have characterized the kinetics and mechanism of OH radical attack on TCE and PCE in y-ray-irradiated aqueous solution. Trichloroethylene was readily decomposed in exponential fashion, with a reported G value of 0.54 pmol J-1. A 10 ppm (76 pM) solution was decontaminated with an absorbed dose of less than 600 Gy. For each OH captured, one C02 molecule, one formic acid molecule and three Cl- ions were generated. These products were created by a series of reactions initiated by OH addition to the unsaturated TCE carbon, which is shown in Eq. (45) ... 

Lucite and Plexiglas (polymethyl methacrylate as marketed by du Pont and by Rohm and Haas, respectively) and polystyrene are transparent thermoplastic materials. Their machinability is fairly good but somewhat limited by their thermoplasticity. They are strongly attacked by solvents such as acetone. They can be cemented with solvents alone (trichloroethylene) or with such cements as Duco. Over long periods cracks may develop at points of strain, and discoloration may result from prolonged exposure to strong light. 

Direct chlorination of vinyl chloride generates 1,1,2-tnchloroethane [79-00-5] from which vinylidene chloride required for vinylidene polymers is produced. Hydrochlorination of vinylidene chloride produces 1,1,1-trichloroethane [71-55-6], which is a commercially important solvent. Trichloroethylene and perchloroethylene are manufactured by chlorination, hydrochlorination, or oxychlorination reactions involving ethylene. Aromatic solvents or pesticides such as monochlorobenzene, dichlorobenzene, and hexachlorobenzene are produced by reaction of chlorine with benzene. Monochlorobenzene is an intermediate in the manufacture of phenol, insecticide DDT, aniline, and dyes (see Chlorocarbons a>td Chlorohydrocarbons.)... 

Currently, over 100 compounds have been identified as PPs. The literature indicates that induction of peroxisome proliferation is not limited to exogenous chemicals. A number of endogenous substances, such as the steroid hormones, thyroid hormones, mor-phogenes, and fatty acids, are also involved in peroxisome proliferation. Peroxisome proliferation in hepatic parenchymal cells of rats and mice following the administration of clofibrate has been reported by numerous investigators. Compounds that are structurally unrelated to clofibrate, such as acetaminophen and Wy-14,643, can also cause peroxisome proliferation (Table 1). The industrial solvent trichloroethylene, the industrial plasticizers dill-ethyl hexyl) phthalate (DEHP) and di(2-ethyl hexyl) adipate (DEHA), have also been found to be hepatic peroxisome proliferators. 

Extended exposure (e.g., occupational exposure) to a chlorinated solvent like trichloroethylene typically... 

Calculating doses for environmental chemicals is not much more complex. Suppose a local ground water supply has become contaminated with the widely used degreasing solvent, trichloroethylene (TCE). EPA scientists have measured the extent of TCE contamination and found that the water contains 2 micrograms of TCE in each liter of water (how they know this will be discussed a little later). People living above the water have sunk wells, and adults are drinking two liters of the water each day and their children are consuming one liter. 

Bioremediation has been successfully demonstrated for a variety of contaminant classifications. The majority of the studies have focused on petroleum compounds (BTEX, gasoline, diesel, jet fuel, etc.) because of their widespread occurrence as a contaminant. The other major waste classifications where bioremediation has been successful are solvents (toluene, trichloroethylene, etc.), creosote, pulp and paper, pesticides, textiles, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). Table 1 contains a partial list of the microbial genus successfully implemented for these contaminants. For aqueous petroleum contaminants, bacteria and yeasts are the most prevalent degraders. In contaminated soil systems, bacteria and fungi are the microorganisms responsible for degradation. ... 

Solvent exposures also can occur in environmental settings. Major oil spills can induce symptoms from both stress and solvent exposure (Lyons et al. 1999). The novel and movie A Civil Action (Harr 1995) portrays the effect of a trichloroethylene contamination on the community of Woburn, Massachusetts. Hundreds of such hazardous waste sites on the Environmental Protection Agency s National Priorities List contain solvents. Solvents constitute 6 of the 10 most common substances at these sites (Committee on Environmental Epidemiology 1991). 

Industrial solvents Solvents and a wide range of volatile compounds are present in commercial products such as gasoline, paint thinners, aerosol propellants, glues, rubber cements, and shoe polish. Because of their ready availability, these substances are most frequently abused by children in early adolescence. Active ingredients that have been identified include benzene, hexane, methylethylketone, toluene, and trichloroethylene. Many of these are toxic to the Uver, kidneys, lungs, bone marrow, and peripheral nerves and cause brain damage in animals. 

Performance The evidence from the cases is mixed. Supporting the relative effectiveness of CAC is the U.S. effort to phase out the solvent trichloroethylene (TCE), in which EPA ultimately mandated limits. The El aspects of the rule did not attract significant industry participation. In phasing out leaded gasoline in Europe, progress would have significantly slowed without mandating catalytic converters and maximum lead content in addition to tax differentials. 

A retrospective cohort study of 14,457 aircraft maintenance woikers at Hill Air Force Base, Utah, was undertaken by Spirtas et al. (1991) to determine if occupational exposure to over 20 solvents, including trichloroethylene and tetrachloroethylene, posed an increased risk of mortality. Deaths due to multiple myeloma or non-Hodgkin s lymphoma were elevated in female woikers exposed to tetrachloroethylene for at least 1 year. However, confidenee in these data is low primarily beeause multiple and overlapping exposure to more than one chemieal was considerable. In addition, the levels of tetrachloroethylene to which the workers were exposed were not provided, and lifestyle factors such as smoking and alcohol consumption were not assessed. 

NitrHe Rubber Gloves —Provide protection from chlorinated solvents (trichloroethylene, per-chloroethylene, etc.). They are intended for jobs requiring dexterity and sensitivity, yet they stand up under mechanical use even after prolonged exposure to substances that cause other glove materials to deteriorate. They also resist abrasion, puncturing, snagging, and tearing. 

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