1,1,2-Trichloroethane, solvent effect

In order to compare the shifts of flie conformational equilibrium position with solvent effects it is advisable to select species exhibiting negligible cavity effects on the equilibrium position. Two firm candidates in this respect are the conformational equilibria of 1,2,2-trichloroethane and the equilibrium between the equatorial and axial forms of 2-chlorocyclohexanone both are accurately described by our scales. ... 

Lipase and others Activated PEG2 Effect of water and solvent Benzene, trichloroethane, dimethylsulfoxide 59, 67, 68... 

SolubiHty of the three commercial polysulfones foUows the order PSF > PES > PPSF. At room temperature, all three of these polysulfones as weU as the vast majority of other aromatic sulfone-based polymers can be readily dissolved in a few highly polar solvents to form stable solutions. These solvents include NMP, DMAc, pyridine, and aniline. 1,1,2-Trichloroethane and 1,1,2,2-tetrachloroethane are also suitable solvents but are less desirable because of their potentially harmful health effects. PSF is also readily soluble in a host of less polar solvents by virtue of its lower solubiHty parameter. 

Other important determinants of the effects of compounds, especially solvents, are their partition coefficients, e.g., blood-tissue partition coefficients, which determine the distribution of the compound in the body. The air-blood partition coefficient is also important for the absorption of a compound because it determines how quickly the compound can be absorbed from the airspace of the lungs into the circulation. An example of a compound that has a high air-blood partition coefficient is trichloroethane (low blood solubility) whereas most organic solvents (e.g., benzene analogues) have low air-blood partition coefficients (high blood solubility). 

Efforts to identify the specific compounds responsible for the psychotropic effects of volatile solvents are complicated by the fact that many of these products contain more than one potentially psychoactive ingredient. Another factor obscuring the identity of the psychoactive ingredients of these agents is that patients addicted to these compounds frequendy seek the effects not of the product s primary ingredient but of a secondary ingredient such as the propellant gas (e.g., nitrous oxide). To date, the best-studied psychoactive compounds identified in volatile solvents include toluene, 1,1,1-trichloroethane, and trichloroethylene. However, other less well studied compounds, such as benzene, acetone, and methanol, also appear to have significant psychoactive effects. 

Tolerance is characterized by reduced responsiveness to the initial effects of a drug after repeated exposure or reduced responsiveness to a related compound (i.e., cross-tolerance). Animal studies have not provided conclusive evidence of tolerance to the effects of the centrally active compounds in toluene or trichloroethane (Moser and Balster 1981 Moser et al. 1985). Observations in humans, on the other hand, have documented pronounced tolerance among subjects who chronically inhale substances with high concentrations of toluene (Glaser and Massengale 1962 Press and Done 1967) and butane (Evans and Raistrick 1987). Kono et al. (2001) showed that tolerance to the reinforcing effects of solvents is comparable to that conditioned by nicotine but less intense than that reported with alcohol or methamphetamine use. 

Inhalant intoxication dehrium can occur as a consequence of disturbances in dopaminergic, glutamatergic, and GABAergic neu to transmission secondary to acute, high-level exposure to psychoactive ingredients in solvents such as toluene, trichloroethane, and trichloroethylene. Systemic effects of solvent inhalation such as cerebral hypoxia and/or metabolic acidosis may also be involved (Rosenberg 1982). Under these circumstances, inhalant intoxication dehrium develops over a short period of time (usually hours to days) and tends to fluctuate during the course of the day. Usually, the delirium resolves as the intoxication ends or within a few hours after cessation of use. 

Topical application of a single 2 mL dose of undiluted -hexane had no effect on survival or body weight in exposed guinea pigs observed for 35 days after exposure (Wahlberg and Boman 1979). Deaths and/or effects on body weight were seen with similar doses of other common industrial solvents tested in this study (carbon tetrachloride, dimethylformamide, ethylene glycol monobutylether, 1,1,1-trichloroethane, and trichlorethylene). 

Toxicity Any acute exposure to vapors of 1,1,1-trichloroethane leads to irritation of the nose, throat, and eyes, and results in headaches. Exposure to high concentrations or vapors of 1,1,1-trichloroethane is known to cause damage to the CNS, leading to behavioral disorders, dizzy spells, sleepiness, and, in some cases, coma reversible injuries to the liver and kidneys also have been observed. Overexposure of 1,1,1-trichloroethane in occupational/work environments causes headache, CNS depression, irritation to eyes, dermatitis, and cardiac arrhythmias. Effects of repeated or long-term exposure to the solvent causes visual problems, loss of coordination, reduction of the tactile sensitivity of the skin, trembling, giddiness, anxiety, and slowing of the pulse rate. 

The /nfpr-molecular NOE is mentioned above briefly. It is of course this which makes it desirable to use samples in a solvent without nuclei of high for these experiments. There have, however, been few detailed studies of this effect. (234) A density matrix description (235) has been successfully applied to the effect upon the solute (1,1,2-trichloroethane) protons of irradiating the solvent (Me4Si) resonance (235) and differential effects upon the resonances of the [AB]2 spin system provided by the protons of o-dichlorobenzene have been used to aid the assignment. (236)... 

Inhalation of volatile organic solvents can produce acute depressant effects and even death in humans when inhalation is concurrent with exposure to other depressants. For example, combined ingestion of ethanol and inhalation of carbon tetrachloride or trichloroethylene produces enhanced depressant effects, and toluene and 1,1,1-trichloroethane enhance the effects of CNS depressant drugsJ2 ... 

The adsorbents silica gel, alumina, CaX zeolite and activated carbon were examined for their activity to adsorb phosgene [264]. Of these, the zeolite and the activated carbon were noted to be most effective. The carbon material was reported to completely adsorb small traces of phosgene from 1,1,1-trichloroethane upon stirring both adsorbent and solvent at room temperature for about 3 h [264]. Zeolite 13X is recommended for removing phosgene from trichloromethane (chloroform) [302]. 

In humans, long-term exposure to high 1,1,1-trichloroethane vapor concentrations can have toxic effects on the heart that persist beyond the period of exposure. While experiments in animals have shown that arrhythmias produced by 1,1,1-trichloroethane and epinephrine quickly subside after the cessation of exposure (Carlson 1981 Clark and Tinston 1973), three human cases involved ventricular arrhythmias that persisted for 2 weeks or more after solvent exposure ended (McLeod et al. 1987 Wright and Strobl 1984). In all 3 cases, the subjects had been exposed repeatedly to high (unspecified) 1,1,1-trichloroethane concentrations. Echocardiograms revealed mild left ventricular dilation in one patient and slightly dilated left atrium in another, as well as impaired left ventricle function in both (McLeod et al. 1987.) Chronic exposure (<250 ppm) to 1,1,1-trichloroethane had no... 

The mechanism by which 1,1,1-trichloroethane and other organic solvents depress the central nervous system is poorly understood, but is thought to involve interactions of the parent compound with lipids and/or proteinaceous components of neural membranes (Evans and Balster 1991). No known methods specifically counteract the central nervous system effects of 1,1,1-trichloroethane. Because the specific cellular or biochemical nature of central nervous system depression is poorly understood, it is difficult to propose any method to interfere with this effect of 1,1,1 -trichloroethane, other than to prevent further exposure to the compound so that it can be cleared from the body. 

Shah HC, Lal H. 1976. Effects of 1,1.1-trichloroethane administered by different routes and in different solvents on barbiturate hypnosis and metabolism in mice. J Toxicol Environ Health 1 807-816. 

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