Industrial solvents toluene

Toluene Industrial solvent used in the manufacture of explosives, dyes, coatings and other organic substances and as a gasoline additive. 

The use of solvents in the chemical industry and in the chemical-related industries is ubiquitous. Beyond chemical industries, solvent use has become an integral part of life in the twenty-first century. In 1991, the production of the 25 most commonly used solvents was more than 26 million tons per year. According to EPCRA section 313 data, of the chemicals and chemical categories tracked by the program in 1994, five of the top 10 chemicals released or disposed of were solvents, and included methanol, toluene, xylene, methyl ethyl ketone, and dichloromethane. The total quantity of these chemicals released or disposed of was over 687 million pounds, which accounts for 27% of the total quantity of TRl-listed chemicals released and disposed of in that year (Sullivan, 1997). 

The solvent employed in the first commercial installation, of the Indian Refining Co., was a mixture of acetone and benzene (90% grade). In the subsequent development of the process by The Texas Co., a large number of solvents were found to be satisfactory. At present, the process normally employs a mixture of methyl ethyl ketone and industrial grade benzene, which have been found to be admirably suitable and provide a relatively low cost solvent. Toluene is substituted for all or part of the benzene when low chilling temperatures are required to obtain oils of very low pour point, as benzene may crystallize out from the mixture at these lower temperatures. 

Four types of inhalants are abused (1) anesthetic gases (2) industrial solvents, including a variety of hydrocarbons, such as toluene (3) aerosol propellants, such as various fluorocarbons and (4) organic nitrites, such as amyl or butyl nitrite. The mode of action of the inhalant anesthetics has been discussed in Chapter 25 General Anesthetics. 

Industrial solvents include gasoline, and various toxins such as toluene, benzene, and... 

Xylenes and ethylbenzene (Figure 13.7) are common gasoline constituents, industrial solvents, and reagents, so human exposure to these materials is common. The absorption (primarily through inhalation), metabolism, and effects of these solvents are generally similar to those of toluene. Effects are largely on the central nervous system. Effects of xylenes and ethylbenzene on organs other than the central nervous system appear to be limited. 

Organic solvents, which induce CYP2E1, are comprised of a few broad chemical classes, including hydrocarbons such as benzene and toluene, halogenated aliphatic compounds such as carbon tetrachloride and dichloroethane, aliphatic alcohols such as ethanol, and hydroxyethers such as 2-methoxyethanol. Industrial solvents are frequently mixtures of several compounds. The most frequent solvent-associated toxicity occurs from occupational exposure. A number of organic solvents have been examined for their effects on the immune system, and the requirement for their bioactivation to produce immunotoxicity has been well established. 

Cymene or isopropyltoluene is produced via alkylation of toluene with propylene. Cymene is an important intermediate in the production of cresol, and it is also used as an industrial solvent. Again, for both environmental and economic reasons, the use of zeolitic materials for this conversion has been studied. For example, Flockhart et al. have used zeolite Y to effect this reaction (7). They observed that the state of the zeolite, including its degree of ion-exchange and the temperature at which it was calcined, strongly affected the distribution of cymene isomers obtained. In order to enhance the selectivity to para-cymene, the direct precursor to para-cresol, various studies have focused on the use of surface modified zeolites, for example, ZSM-5 materials, including those produced by chemical vapor deposition (CVD) of silicate esters. These species serve to reduce surface acidity and change limit diffusion within the crystal. 

Benzene and its simple alkyl derivatives are the building blocks of the aromatic chemical industry and are also important solvents for many reactions and processes. The simplest derivative, toluene(methylbenzene, 1), is the source of a range of nitrotoluenes and is one of the most important industrial solvents. The three isomeric dimethylbenzenes, o-, m- and p-xylene (2-4) are often used as a mixture in industrial solvents. 

Some industrial solvents are found on the Proposition 65 Hst. As of January 1, 1993 (2), benzene, carbon tetrachloride, chloroform, methjlene chloride, 1,4-dioxane, 2-nitropropane, and perchloroethylene have been Hsted as substances known to the state of California to cause cancer. Ethji alcohol in alcohoHc beverages, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethjiene glycol monoethyl ether acetate, and toluene are Hsted as substances known to the state of California to cause reproductive toxicity. Because the Hst is being expanded periodically, it is necessary for a user of industrial solvents to maintain awareness of the Proposition 65 Hst. 

Because benzene is nonpolar, it cannot be passed in urine, and will remain in the body until oxidized. Benzene itself is not dangerous to health, but in order to be passed, it is oxidized by cytochrome P-450 in the liver. This produces benzene oxide, a highly teratogenic and carcinogenic compound. Benzene has been replaced by toluene as an industrial solvent, because toluene can be oxidized to benzoic acid, which is mostly harmless to health, and is quickly passed. The decomposition of benzoic acid into benzene and carbon dioxide in soda pop has become an issue recently. 

When aromatic compounds are sulfonated by chlorosulfuric acid side reactions such as formation of the sulfonyl chloride or even the sulfone occur to a greater extent than in the procedures described above. For example, o- and p-toluenesulfonyl chloride are produced industrially from toluene and an excess of chlorosulfuric acid. Nevertheless, this acid can be used for introducing the sulfonic acid group if the proportions of the reactants, the temperature, and the solvent are selected correctly. 

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. 

Male preteen children are most likely to experiment with solvent inhalation. Abuse of nitrous oxide is relatively common. Toxic inhalants such as heptane, hexane, methylethylketone, toluene, and trichloroethylene may result in central and peripheral neurotoxicity, liver and kidney damage, and pulmonary disease. Sudden death has occurred following inhalation of fluorocarbons. Industrial solvents rarely cause methemoglobinemia, but this (and headaches) may occur following excessive use of nitrites. The answer is (C). 

Toluene is derived from coal tar as well as petroleum. It occurs in gasoline and many petroleum solvents. Toluene is used to produce trinitrotoluene (TNT), toluene diisocyanate, and benzene as an ingredient for dyes, drugs, and detergents and as an industrial solvent for rubbers, paints, coatings, and oils. 

Benzene and toluene are excellent laboratory and industrial solvents. In addition, they are the starting materials for the synthesis of hundreds of other valuable aromatic compounds that are intermediates in the manufacture of a wide variety of commercial products, including the important polymers Bakelite and polystyrene (see > Table 2.4). 

Tables 14.25.1 and 14.25.2 provide data on the reported releases and transfers of solvents by the US rubber and plastics industry. These industries contribute small amounts of VOC which are in the range of0.00001-0.00005 kg VOC/kg of processed rubber. It was the ninth largest contributor to releases and transfers of all US industries. Dichloromethane, toluene, carbon disulfide, methyl ethyl ketone, methanol, 1,1,1-trichloroethane, hexane, methyl isobutyl ketone, and xylene are emitted in very large quantities.

In the packaging printing industry solvents like ethyl acetate, ethanol, ketones, tetrahydrofuran (THF), hexane and toluene are used in printing. The solvent laden air generally contains between 2 and 15 g/m of solvent and, depending on the season, 5-18 g/m of water. 

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