Oxygen deficiency, effects

TABLE 26-25 Effects of Breathing Oxygen-Deficient Atmospheres... 

Exposures to chemicals, resulting in toxic effects or oxygen-deficient atmospheres, may arise in a variety of industrial situations. A summary of common sources is given in Table 5.18 clearly this is not exhaustive since exposure may result whenever materials are mixed, machined, heated, dispersed or otherwise processed or used. 

LPG is considered to be non-toxic witli no chronic effects, but the vapour is slightly anaesthetic. In sufficiently high concentrations, resulting in oxygen deficiency, it will result in physical asphyxiation. The gases are colourless and odourless but an odorant or stenching agent (e.g. methyl mercaptan or dimethyl sulphide) is normally added to facilitate detection by smell down to approximately 0.4% by volume in air, i.e. one-fifth of the lower flammable limit. The odorant is not added for specific applications, e.g. cosmetic aerosol propellant. 

There is a scarcity of oxygen-transport data for oxygen-deficient actinide oxide systems. Because of this, our understanding and predictive capabilities of the effect of the defect solid state on the properties of reactor fuel systems, as well as on the chemical state of fission products in these systems, are limited. 

The magnetic properties of the new solid solution series SrFe Rui 3 3, (0 < X < 0.5) with distorted perovskite structure, where iron substitutes exclusively as Fe(in) thereby causing oxygen deficiency, has also been studied by Greenwood s group [147] using both u and Fe Mossbauer spectroscopy. Iron substitution was found to have little effect on the magnetic behavior of Ru(IV) provided that X remains small (x < 0.2). 

The authors ascribed the high activity of Au/thoria to a Schottky junction effect between the metal and oxide leading to an enhancement of active OH groups associated with oxygen deficiencies. The authors did observe formation of formate, carbonate, and bicarbonate species, but are still elucidating which, if any, of the species are important for the mechanism. 

Masuda Y, Nakamura Y. 1990. Effects of oxygen deficiency and calcium omission on carbon tetrachloride hepatotoxicity in isolated perfused livers from phenobarbital-pretreated rats. Biochem Pharmacol 40 1865-1876. 

---