Diethylene glycol control

Centers for Disease Control and Prevention (CDC). Fatalities associated with ingestion of diethylene glycol-contaminated glycerin used to manufacture acetaminophen syrup—Haiti, November 1995-June 1996 MMWR Morb Mortal Wkly Rep 1996 45 649-50. 

Renwen, H., Feng, Y., Tinszheng, H. and Shiming, G The kinetics of formation of diethylene glycol in preparation of polyethylene terephthalate and its control in reactor design, Angew. Makromol. Chem., 119, 159-172 (1983). 

Various combinations of reactant(s) and process conditions are potentially available to synthesize polyesters [Fakirov, 2002 Goodman, 1988], Polyesters can be produced by direct esterification of a diacid with a diol (Eq. 2-120) or self-condensation of a hydroxy carboxylic acid (Eq. 2-119). Since polyesterification, like many step polymerizations, is an equilibrium reaction, water must be continuously removed to achieve high conversions and high molecular weights. Control of the reaction temperature is important to minimize side reactions such as dehydration of the diol to form diethylene glycol... 

Fumaric and itaconic acids are also used as the diacid component. Most reaction formulations involve a mixture of a saturated diacid (iso- and terephthalic, adipic) with the unsaturated diacid or anhydride in appropriate proportions to control the density of crosslinking (which depends on the carbon-carbon double-bond content of the prepolymer) for specific applications [Parker and Peffer, 1977 Selley, 1988], Propylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, and bisphenol A are also used in place of ethylene glycol as the diol component. Aromatic reactants are used in the formulation to improve the hardness, rigidity, and heat resistance of the crosslinked product. Halogenated reactants are used to impart flame resistance. 

Fuel system icing inhibitors such as EGME (ethylene glycol monoethyl ether) and DEGME (diethylene glycol monoethyl ether) contain oxygen, but are added within controlled limits. 

Description Purified EO or a water/EO mixture is combined with recycle water and heated to reaction conditions. In the tubular reactor (1), essentially all EO is thermally converted into monoethylene glycol (MEG) with diethylene glycol (DEG) and triethylene glycol (TEG) as co-products in minor amounts. Excess water, required to achieve a high MEG selectivity is evaporated in a multi-stage evaporator (2,3). The last evaporator (4) produces low-pressure steam, which is used as a heat medium for other units in the plant. Crude glycol is purified in a series of vacuum columns (5,6,7,8). Selectivity toward MEG can be controlled with the feed composition. 

The primary function of the kidneys is to rid the body of waste materials that are either ingested or produced by metabolism, and to control the volume and composition of the body fluids. The toxins absorbed by the different routes are biotransformed and enter the blood. They are then eliminated through the urine, feces, and air. Since the kidneys receive approximately a quarter of the cardiac output, it is an important organ for the exposure of toxicants and their metabolites. Recent incidents of pet food toxicity and diethylene glycol toxicity indicate that contamination of animal and human food and drugs, respectively, can lead to severe mortahty and morbidity as a result of renal toxicity. 

In 1999, WHO published a report on the control and safe trade of starting materials for pharmaceutical products in English, French, Spanish, Russian, Chinese, and Arabic, based on recommendations from a meeting of experts in Geneva in May 1998. The meeting was inspired by several recent incidents of contamination with highly toxic solvent diethylene glycol. 

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