Tungsten toxicity

Handling and Toxicity. Tungsten hexafluoride is irritating and corrosive to the upper and lower airways, eyes, and skin. It is extremely corrosive to the skin, producing bums typical of hydrofluoric acid. The OSHA permissible exposure limits is set as a time-weighted average of 2.5 mg/kg or 0.2 ppm (22). 

The English company has developed three 12-gauge 5 shot lines in their non-toxic tungsten. TMX mixes iron into the tungsten matrix so it is 20 percent cheaper to produce and gives 90 percent patterns at 40 yards. Impact Multi-Shot is a 60/40 iron/tungsten matrix mix. The third line is Tin Shot - Super Speed. 

Some metals used as metallic coatings are considered nontoxic, such as aluminum, magnesium, iron, tin, indium, molybdenum, tungsten, titanium, tantalum, niobium, bismuth, and the precious metals such as gold, platinum, rhodium, and palladium. However, some of the most important poUutants are metallic contaminants of these metals. Metals that can be bioconcentrated to harmful levels, especially in predators at the top of the food chain, such as mercury, cadmium, and lead are especially problematic. Other metals such as silver, copper, nickel, zinc, and chromium in the hexavalent oxidation state are highly toxic to aquatic Hfe (37,57—60). 

A considerable difference in the toxicity of soluble and insoluble compounds of tungsten has been reported (58). For soluble sodium tungstate,... 

Orally in rats, the toxicity of sodium tungstate was highest, tungsten trioxide was intermediate, and ammonium tungstate [15855-70-6] lowest (59,60). In view of the degree of systemic toxicity of soluble compounds of tungsten, a threshold limit of 1 mg of tungsten per m of air is recommended. 

Removability of Toxic Organic Pollutants from Wastewater in the Primary Tungsten Subcategory... 

Another oxyanion of interest to soil chemists is that of tungsten, which is in itself important but is also important because it forms polymers and reacts with both molybdenum and phosphorus oxyanions to form mixed polymers. Because tungsten species are toxic, its oxyanionic species, including polymers, are of interest [28],... 

Tungsten dust, powder, and fine particles will explode, sometimes spontaneously, in air. The dust of many of tungstens compounds is toxic if inhaled or ingested. 

Toxicology. The soluble compounds of tungsten are distinctly more toxic than the insoluble forms. 

Leanderson P, Sable W Formation of hydroxyl radicals and toxicity of tungsten oxide fibres. Toxicol In Vitro 9(2) 175-183, 1995... 

Cobalt in small amounts is an essential element associated with vitamin B12, but at high levels can be toxic. There are no daily recommended intake levels for cobalt. Intestinal bacteria use cobalt to produce cobalamin, which in turn is an essential component of vitamin B12. Industrially, cobalt is used in pigments, permanent magnets, and as an alloy to harden metals as in tungsten carbide blades or drills. 

Tungdten(or Wolfram) Hexafluoride, WFfl, mw 297.86 colorless gas or It yel liquid toxic sp gr(liq) 3.44, fr p 2.5°, bp 19 5°. Can be prepd by direct fluorinarion of powdered tungsten, followed by distillation under pressure. Used for vapor phase deposition of tungsten and as fluorinaring agent Refs 1) Gmelin-Kraut Syst Number 54(1933), 155 2) Lange (1961), 32 4 3) CondChem-... 

Russel, J.A., Roy, M.K. and Sanford, J.C. (1992) Physical trauma and tungsten toxicity reduce the efficiency of biolistic transformation. Plant Physiology 98, 1 050-1 056. 

Cobalt is an essential element that is part of vitamin B12, or cobalamin, a coenzyme that is essential in the formation of proteins, nucleic acids, and red blood cells. Although cobalt poisoning is not common, excessive levels can be harmful. Most cases of human exposure to toxic levels of cobalt have occurred through inhalation in the workplace. Many exposures have been suffered by workers working with hard metal alloys of cobalt and tungsten carbide, where very fine particles... 

Domingo, J.L. 2002. Vanadium and tungsten derivatives as antidiabetic agents A review of their toxic effects. Biol. Trace Elem. Res. 88 97-112. 

These catalytic oxidations, unlike those with molybdenum and tungsten, require the continuous removal of water by azeotrope to regenerate the active oxidant. In addition, selenium and arsenic are highly toxic, and their total containment within the process presents some difficulties. Although organic resin-bound analogues have been reported,87 it is still believed that the molybdenum and tungsten catalytic chemistry is much more amenable to current and future use in clean industrial processes. 

Interactions Overabundance of one trace element can interfere with the metabolic use of another element available at normal levels. For example, addition of large amounts of zinc to a diet interferes with (antagonizes) intestinal copper absorption, resulting in copper deficiency from a diet with adequate copper content. Copper deficiency can provoke iron deficiency and anaemia. Molybdenum deficiency in animals can be induced by co-administration of large amounts of the similar element tungsten. Iron deficiency can also increase retention of cadmium and lead, and selenium has been proposed to protect against cadmium and mercury toxicity. 

Violent reaction with alcohols, N-aryl sulfinamides, dimethyl formamide, polychlorobiphenyl, sodium hydroxide, hydrochloric acid + dinitroanilines. Incandescent reaction when warmed with cesium oxide (above 150°), tellurium, arsenic, tungsten dioxide. Potentially dangerous reaction with hydrocarbons + Lewis acids releases toxic and reactive HCl gas. 

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