Toluene regulations

Temperature Control.—For moderate accuracy, the temperature of the column should be controlled to within 0.2 K if the solute vapour pressure is known to be better than 1 per cent. A good air thermostat is capable of this control. It is, however, much easier to control the temperature of the water bath, and a simple on-off relay in conjunction with a toluene regulator and backing heater is capable of controlling the temperature to 0.01 K. This is the order of temperature control required for the accurate determination of activity coefficients. 

Tables 16 and 17 Hst tke analytical test methods for different properties of interest. The Manufacturing Chemists Association, Inc. (MCA) has pubUshed the Chemical Safety Data Sheet SD 63, which describes in detail procedures for safe handling of use of toluene (46). The Interstate Commerce Commission classifies toluene as a flammable Hquid. Accordingly, it must be packaged in authorized containers, and shipping must comply with ICC regulations. Properties related to safe handling are autoignition temperature, 536°C explosive limits, 1.27—7.0 vol % in air and flash point 4.4°C, closed cup.

Use as Solvent. Toluene is more important as a solvent than either benzene or xylene. Solvent use accounts for ca 14% of the total U.S. toluene demand for chemicals. About two-thirds of the solvent use is in paints and coatings the remainder is in adhesives, inks, pharmaceuticals, and other formulated products utilizing a solvent carrier. Use of toluene as solvent in surface coatings has been declining, primarily because of various environmental and health regulations. It is being replaced by other solvents, such as esters and ketones, and by changing the product formulation to use either fully soHd systems or water-based emulsion systems. 

The molecular weight may be regulated by controlled degradation of the alkali cellulose in the presence of air. This can be done either before or during etherification. The molecular weight of commercial grades is usually expressed indirectly as viscosity of a 5% solution in an 80 20 toluene-ethanol mixture. 

Preparation of l9-Norandrost-A-ene-3, l-dionef A solution of 1.1 g of 10y5-cyano-19-norandrost-5-ene-3,17-dione bis-ethylene ketal in a mixture of 15 ml of ethanol and 15 ml of toluene is carefully added to a vigorously stirred suspension of 10 g of sodium in 150 ml of boiling toluene. The addition is regulated to maintain the reaction mixture at the boiling point of the solvent. Another 40 ml of anhydrous ethanol is then added at the same rate. The solution is cooled and the excess of sodium is decomposed by addition of 95% ethanol. The reaction mixture is then diluted with water, the toluene layer separated and the aqueous phase extracted twice with ether. The organic solution is washed with water, dried and evaporated to yield 1 g of an amorphous mixture of the bis-ethylene ketals of 19- norahd-rost-5- and -5(10)-ene-3,17-dione (Note 1). 

Unlike carbon dioxide and water that are the inevitable by products of complete combustion of hydrocarbons, species such as carbon monoxide, ethene, toluene, and formaldehyde can be emitted because combustion has been interrupted before completion. Many factors lead to emissions from incomplete combustion. Emitted unburned hydrocarbons and carbon monoxide are regulated pollutants that must be eliminated. In automobiles with spark ignited engines, these emissions are almost entirely removed by the catalytic converter. 

Strains may be able to regulate the pathway of degradation of toluene to the availability of oxygen aerobic degradation by dioxygenation and under denitrifying conditions in the absence of oxygen by the benzylsuccinate pathway. 

Kiihner S, L Wohlbrand, I Fritz, W Wruck, C Hultschig, P Hufnagel, M Kube, R Reinhardt, R Rabus (2005) Substrate-dependent regulation of anaerobic degradation pathways for toluene and ethylbenzene in a denitrifying bacterium strain EbNl. J Bacteriol 187 1493-1503. 

Furukawa K, JR Simon, AM Chakrabarty (1983) Common induction and regulation of biphenyl, xylene/toluene, and salicylate catabolism in Pseudomonas paucimobilis. J Bacteriol 154 1356-1362. 

So acrylic acid would bear R25 (LD50 o-n 34 mg/kg) R22 (LD50 o-r 235 340 353 355) or no code (LD50 o-r 2590). Benzene, toluene, 1-propanol, dichloromethane, etc., can be either R22 or have no code by ingestion depending on the values (labour regulations actually chose not to allocate any acute toxicity code to them). 

The washed solvent is collected in drums for disposal. The aqueous stream, after analysis, can be sent directly to the publicly owned treatment works (POTW). Limits have not yet been set for dumping versus waste disposal in drums. If the solvent being used is a regulated substance (such as toluene), drum disposal of the HLO may be the only acceptable way. 

Some commercial grades of toluene contain small amounts of benzene as an impurity. Benzene is an OSHA regulated material. 

The xylenes are flammable and are shipped under the same regulations and using the same methods as benzene and toluene rank cars, trucks, barges, and tankers. Pipeline movements are limited. Toxicological problems dictate handling in closed systems like benzene and toluene. 

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