Other halogenated hydrocarbons

HaloaUcanes other than the chloroalkanes, especially those with stractural homology to known hepatotoxic chloroalkanes, should be considered potentially hepatotoxic despite little industrial use as solvents. Case reports of bromoethane and hydrochlorofluorocarbon poisonings with hepatotoxicity have been reported in the literature.  

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P.M. Jeffers and N.L. Wolfe, Hydrolysis of methyl bromide, ethyl bromide, chloropicrin, 1,4-dichloro-2-butene, and other halogenated hydrocarbons, in Fumigants Environmental Fate, Exposure, and Analysis, ed. J.N. Seiber, J.A. Knuteson, J.E. Woodrow, N.L. Wolfe, M.V. Yates, and S.R. Yates, ACS Symposium Series No. 652, American Chemical Society, Washington, DC, pp. 32-41 (1997). 

Halogenated hydrocarbon inhalation anesthetics may increase intracranial and CSF pressure. Cardiovascular effects include decreased myocardial contractility and stroke volume leading to lower arterial blood pressure. Malignant hyperthermia may occur with all inhalation anesthetics except nitrous oxide but has most commonly been seen with halothane. Especially halothane but probably also the other halogenated hydrocarbons have the potential for acute or chronic hepatic toxicity. Halothane has been almost completely replaced in modern anesthesia practice by newer agents. 

Halothane and all other halogenated hydrocarbons cause some relaxation of skeletal muscle. The relaxation is not adequate when muscle paralysis is a requirement of the operative procedure, but halothane s action will... 

Desflurane, like other halogenated hydrocarbon anesthetics, causes a decrease in blood pressure. The reduced pressure occurs primarily as a consequence of decreased vascular resistance, and since cardiac output is well maintained, tissue perfusion is preserved. 

Sevoflurane undergoes hepatic biotransformation (about 3% of the inhaled dose), and it is somewhat degraded by conventional CO2 absorbents. The degradation product from the absorbent has been reported to be nephrotoxic, although the report is controversial and not substantiated by more recent studies. Sevoflurane s actions on skeletal muscle and on vascular regulation within the CNS are similar to those described for the other halogenated hydrocarbon anesthetics. 

Decaborane (and possibly some other boron hydrides) in the presence of carbon tetrachloride, and possibly other halogenated hydrocarbons, forms a very shock-sensitive high explosive. 

Others Halogenated hydrocarbons, Arsenic, Cyanide (Colorimetric )... 

Organic fluorides are generally less toxic than other halogenated hydrocarbons. Fluorocarbons are chemicaUy inert to most materials but can react violendy with barium, sodium, and potassium. Fluoroamides react violendy with lithium tetrahydroaluminate and with sodium at very high temperatures. Some fluorinated cyclopropenyl methyl ethers react violently with water or methanol. Some fluorodinitro compounds of methane and ethane are sensitive explosives. When heated to decomposition they emit toxic fumes of F. Common air contaminants. 

Recoveries of PBBs using established methods are in the range of 80-90% [33]. The solvent system used for sample extraction can affect recovery [2]. PBBs adsorb to glass more tenaciously than other halogenated hydrocarbons, and are not easy to remove by the usual cleaning methods. Using disposable glassware prevents erroneous values in the data [34]. 

In general, starch triacetates are soluble in acetic acid and, except perhaps for potato starch triacetate, are soluble in chloroform, 1,1,2-tri-chloroethane, tetrachloroethane, and other halogenated hydrocarbons. High grade starch triacetates do not appear to be soluble in ethyl acetate or alcohol, while some controversy exists as to the extent of their solubility in pyridine and acetone. Waxy com starch triacetate, perhaps due to its smaller molecular weight, is readily soluble in a wide variety of organic solvents. 

Synthesis of carbonyl difluoride from other halogenated hydrocarbons... 

I, 1,1 -trichloroethane and other halogenated hydrocarbons are generally supportive and rely on the body s ability to eliminate rapidly 1,1,1-trichloroethane and its metabolites. Animal studies indicate that intravenous injection or infusion of calcium gluconate or phenylephrine are protective against acute blood pressure reduction caused by exposure to 1,1,1-trichloroethane (Herd et al. 1974). Further animal testing is needed to assess whether these compounds might be used to resuscitate individuals exposed to high concentrations of 1,1,1-trichloroethane. 

Other halogenated hydrocarbons are very useful in medicine. They were among the first anesthetics (pain relievers) used routinely in medical practice. These chemicals played a central role as the studies of medicine and dentistry advanced into modern times. 

B. Anesthetic effects. Like other halogenated hydrocarbons, DCM can cause CNS depression and general anesthesia. 

Tetiachloroethylene applied to a patch of abdominal skin of ICR mice for 15 minutes/week resulted in an in vivo absorption rate of 0.24 mg/cm%our (Tsuruta 1975). An in vitro study using excised rat (SD-JCL) skin demonstrated that the rate of penetration by tetiachloroethylene was much slower than that of several other halogenated hydrocarbons (i.e., 2,070 times slower than that of the fastest compound, dichloromethane), and the measured rate for tetiachloroethylene penetration was 0.005 mg/cm%our. The penetration rate observed in the in vitro method was 44 times slower than that observed in the in vivo method. The difference may result from the solubility of the substance in 0.9% sodium chloride and its solubility in body fluids (Tsumta 1977). 

Ozone depletion potential represents the potential of depletion of the ozone layer due to the emissions of chlorofluorocarbon compounds and other halogenated hydrocarbons. 

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