Toluene poisoning

Carbon deposition and dioxygen bum off on freshly reduced, carbon monoxide and toluene poisoned Pt/aiumina at 873 K ... 

Ferreiro JL, Isern Longares JA. [Chronic toluene poisoning.] Neurologia 1990 5(6) 205-7. 

According to this book, "in the few cases of acute toluene poisoning reported (industrially), the effect has been that of a narcotic, the workman passing through a state of intoxication into one of coma. Recovery following removal from exposure has been the rule."... 

EXPLOSION and FIRE CONCERNS not flammable NFPA rating Health 3, Flammability 0, Reactivity 1 enhances combustion of organic matter and other combustible materials reacts violently with cyclohexane, fluorine, formaldehyde, and alcohols violent reaction with nitrobenzene, petroleum and toluene poisonous gases may be produced in fire decomposition emits toxic fumes of oxides of nitrogen use water spray or other suitable agent for firefighting purposes. 

Other mixtures which may be employed are carbon tetrachloride (b.p. 77°) and toluene (b.p. 110-111°) chloroform (b.p. 61°) and toluene methyl alcohol (b.p. 65°) and water (b.p. 100°). The last example is of interest because almost pure methyl alcohol may be isolated no constant boiling point mixture (or azeotropic mixture) is formed (compare ethyl alcohol and water, Sections 1,4 and 1,5). Attention is directed to the poisonous character of methyl alcohol the vapour should therefore not be inhaled. 

The common impurities found in amines are nitro compounds (if prepared by reduction), the corresponding halides (if prepared from them) and the corresponding carbamate salts. Amines are dissolved in aqueous acid, the pH of the solution being at least three units below the pKg value of the base to ensure almost complete formation of the cation. They are extracted with diethyl ether to remove neutral impurities and to decompose the carbamate salts. The solution is then made strongly alkaline and the amines that separate are extracted into a suitable solvent (ether or toluene) or steam distilled. The latter process removes coloured impurities. Note that chloroform cannot be used as a solvent for primary amines because, in the presence of alkali, poisonous carbylamines (isocyanides) are formed. However, chloroform is a useful solvent for the extraction of heterocyclic bases. In this case it has the added advantage that while the extract is being freed from the chloroform most of the moisture is removed with the solvent. 

Benzene is a flammable liquid and its vapors are toxic and explosive. Low concentrations are dangerous on continued inhalation because benzene affects the blood forming function of the bone marrow and it is a cancirogen. Dermatitis may result from repeated skin contact. Alkyl derivatives such as toluene and xylenes are far less toxic and are, therefore, much safer than benzene for use in solvents. Some of the symptoms of benzene poisoning are dizziness, constriction of the chest, and tightening of the leg muscles. 

The reaction is performed either noncatalytically at temperatures of 600-800°C and at pressures of 30-100 bar, or catalytically on a CoO contact at 550-650°C and at the same pressure of 30-100 bar. A problem of the catalytic process is the poisoning of the catalyst by deposition of coke-like material, but the conversion, yield, and purity of the benzene are better (>99%) in the catalytic than in the noncatalytic process. In the noncatalytic process the benzene selectivity is about 95%, if the conversion of the toluene is kept at 60-80%. 

Unbumt gasoline and cracked hydrocarbons such as ethylene and propylene are also substantial constituents of exhaust. Gasoline contains additives such as benzene, toluene and branched hydrocarbons to achieve the necessary octane numbers. The direct emission of these volatile compounds, e.g. at gas stations, is a significant source of air pollution. Leaded fuels, containing antiknock additions such as tetra-ethyl-lead, have been abandoned because lead poisons both human beings and the three-way exhaust catalyst, especially for the removal of NO by rhodium. 

Enantioselective hydrogenation of 2,3-butanedione and 3,4-hexanedione has been studied over cinchonidine - Pt/Al203 catalyst system in the presence or absence of achiral tertiary amines (quinuclidine, DABCO) using solvents such as toluene and ethanol. Kinetic results confirmed that (i) added achiral tertiary amines increase both the reaction rate and the enantioselectivity, (ii) both substrates have a strong poisoning effect, (iii) an accurate purification of the substrates is needed to get adequate kinetic data. The observed poisoning effect is attributed to the oligomers formed from diketones. 

The types of medical data that help accident investigations include (1) type and level of toxic or abusive substances in the blood, (2) location and magnitude of injuries, (3) type of poisoning (carbon monoxide, toluene, etc.), (4) signs of suffocation, (5) signs of heat exposure or heat exhaustion, and (6) signs of eye irritation. 

Borgna, A., Speulveda, J., Magni, S.I., and Apesteguia, A.R. (2004) Active sites in alkylation of toluene with methanol a smdy by selective add-base poisoning. Appl Catal A, 276, 207-215. 

Recently, alkylation of alkyl aromatic hydrocarbons such as toluene, ethylbenzene, cumene, and xylenes with ethene, propene, and 1,2-diphenylethene was investigated by Kijenski et al. (245), who used superbasic K-MgO and K-AI2O3 catalysts at low temperature at atmospheric and elevated pressures. The reaction kinetics, EPR measurements of adsorbed intermediates, and the effects of poisoning determined by the radical trap TEMPO (2,2,6,6-tetramethyl-l-piperidinyloxyl, free radical) led the authors to conclude that sites are the catalytically active centers. To demonstrate the importance of strong one-electron donor sites (F ) for the alkylation and the inactivity of strong two-electron donor centers, the ethylation of cumene, ethylbenzene, and toluene was carried out with MgO-10%NaOH. On this catalyst, strong basic two-electron donor sites (27 33) were found, along... 

TOLUENE 2,4-DIISOCYANATE TDI, Hylene T, Mondur TDS, Nacconate 100 Poison, Class B, II 3 1 ... 

Thus, immune-media ted responses can be immediate or delayed and localized or widespread. The response can be restricted to the area of exposure or can be systemic. Similar compounds may cross-react or produce very different responses. Many different foreign compounds can cause an immunotoxic response drugs such as penicillin, halothane, and hydralazine, industrial chemicals such as trimellitic anhydride and toluene di-isocyanate, natural chemicals such as pentadecylcatechol found in poison ivy, food additives such as tartazine, and food constituents such as egg white (albumen). 

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