Toluene, exposion properties

At one time benzene was widely used as a solvent This use virtually disappeared when statistical studies revealed an increased incidence of leukemia among workers exposed to atmospheric levels of benzene as low as 1 ppm Toluene has replaced benzene as an inexpensive organic solvent because it has similar solvent properties but has not been determined to be carcinogenic m the cell systems and at the dose levels that benzene is... 

Phenol was the first commercial antiseptic its introduction into hospitals in the 1870s led to a dramatic decrease in deaths from postoperative infections. Its use for this purpose has long since been abandoned because phenol burns exposed tissue, but many modern antiseptics are phenol derivatives. Toluene has largely replaced benzene as a solvent because it is much less toxic. Oxidation of toluene in the body gives benzoic acid, which is readily eliminated and has none of the toxic properties of the oxidation products of benzene. Indeed, benzoic acid or its sodium salt (Na+, C6H5COO ions) is widely used as a preservative in foods and beverages, including fruit juices and soft drinks. 

The irritancy properties of isophorone have also been observed in humans exposed occupationally to isophorone. In an industrial hygiene survey, Kominsky (1981) reported that the eye and nose irritation complained of by a screen printer could have been caused by 4-minute exposure to 25.7 ppm isophorone, which was measured in the personal breathing zone while the worker was washing a screen. Lee and Frederick (1981) found that eye, respiratory, and skin irritation were among the complaints of 27/35 workers in a printing plant where isophorone and other solvents (xylene, methylene chloride, and toluene) were used. On the day of measurement, two of the screen printers were found to be exposed to 8-hour TWA concentrations of isophorone of 0.7 and 14 ppm, but it was not clear whether these two individuals were among the workers complaining of irritation. The odor threshold for isophorone in air has been reported to be 0.2 ppm (v/v) (Amoore and Hautala 1983). 

Toluene (methylbenzene) does not possess the myelotoxic properties of benzene, nor has it been associated with leukemia. It is, however, a central nervous system depressant and a skin and eye irritant. It is also fetotoxic. See Table 56-1 for the TLVs. Exposure to 800 ppm can lead to severe fatigue and ataxia 10,000 ppm can produce rapid loss of consciousness. Chronic effects of long-term toluene exposure are unclear because human studies indicating behavioral effects usually concern exposures to several solvents. In limited occupational studies, however, metabolic interactions and modification of toluene s effects have not been observed in workers also exposed to other solvents. Less refined grades of toluene contain benzene. 

Biaxially oriented PPS film is transparent and nearly colorless. It has low permeability to water vapor, carbon dioxide, and oxygen. PPS film has a low coefficient of hygroscopic expansion and a low dissipation factor, making it a candidate material for information storage devices and for thin-film capacitors. Chemical and thermal stability of PPS film derives from inherent resin properties. PPS films exposed to toluene or chloroform for 8 weeks retain 75% of their original strength. The UL temperature index rating of PPS film is 160°C for mechanical applications and 180°C for electrical applications. Table 9 summarizes the properties of PPS film. 

The presence of a higher aromatic content In the gasoline resulted In Increased swell and hence Increased deterioration of tensile properties of elastomers exposed to the gasoline and Its mixtures. Addition of benzene to Increase the aromatic content resulted In slightly more detrimental effects on nitrile elastomers than the addition of toluene. The data on all elastomers can be explained In terms of the solubility parameter concept. 

The ammoxidation of substituted toluenes over differently prepared (NH4>2(V0)3(P207)2-and V0(P03)2-phases as well as over (VO)2P207 has been studied by catalytic and in situ-ESR measurements. For effective catalytic performance at least two structural properties were found to be essential i) Closely neighbouring centres must be exposed at the surface which enable the simultaneous adsorption and conversion of the substrate and ii) the catalyst structure must contain building blocks of exchange-coupled ions e. g. in the form of chains or layers which support the electron transport during the redox process. 

The tensile strength data from the container cutouts are reported in Figures 3 and 4. The tensile modulus data are reported in Figures 5 and 6 the tensile property in megaPascals is plotted vs. the storage time at RT or 50°C. No differences in tensile properties were detected between the fluorinated and untreated containers not exposed to toluene. 

Properties Colorless si. vise, liq., nearly odorless very sol. in diethyl ether sol. in ethanol, toluene, water misc. with oxygenated soivs. m.w. 134.18 dens. 1.023 vapor pressure 1 mm (73.8 C) b.p. 233 C flash pt. (OC) 124 C ref. index 1.4410 Toxicology LD50 (oral, rat) 14,850 mg/kg, (IP, mouse) 10 g/kg, (IV, rat) 5800 mg/kg, (skin, rabbit) > 20 ml/kg mildly toxic by ing. primary skin and eye irritant may cause somnolence, tremors, kidney/ureter/blad-der changes mutagenic data TSCA listed Precaution Combustible when exposed to heat and flame can react vigorously with oxidizing materials... 

Properties Water-wh. liq. sol. in alcohol, acetone, toluene insol. in water, petrol, naphtha m.w. 154.10 dens. 1.120-1.125 (25/40 C) flash pt. (COC) HOC ref. index 1.429 Toxicology Toxic and corrosive strong irritant to skin and tissue TSCA listed Precaution DOT Corrosive material combustible when exposed to heat or flame Hazardous Decomp. Prods. Heated to decomp., emits highly toxic fumes of POx Uses Catalyst in coatings, inks, for appliance, automotive, floor, furniture, paper, and other... 

To isolate the metal particles, the matrix material is easily removed by washing with various solvents. The solid mixture is treated with benzene or toluene and yields metal suspensions which when dried and exposed to air heat up and smoke and sometimes ignite the powders then consist of mainly metal oxides with loss of ferromagnetic properties. Washing the powders with octanol renders them air stable by forming a protective film over the particles. Excess octanol can be removed by washing the metal powders with methanol, ethanol, or isopropanol. Such washed powders exhibit air sensitivity. 

The role of support on the performance of noble metals-based catalysts for the total oxidation of aromatic hydrocarbons is essential [38]. Although with a smaller surface area than the typical supports, perovskites also demonstrate good properties as carriers for noble metals. Thus, perovskites of type LaBOs (B = Co, Mn, Fe, Ni) synthesized using the citrate route were used as support for noble metals in total oxidation of toluene [39]. The performances of these catalysts varied in the order Fe>Mn>Co>Ni, and the superior behavior of iron was attributed to the low temperature of calcination and the high stability of the perovskite lattice irrespective of the nature of the stream it was exposed to. The dispersion of palladium at the different stages of the process remained unchanged. 

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