Nickel and soluble compounds

Exposure to nickel metal and soluble compounds (as Ni) should not exceed 0.05 mg/cms (8-hour time-weighted average - 40-hour work week). Nickel sulfide fume and dust is recognized as being potentially carcinogenic. 

The speiss is crushed and ground with 20 pex cent, of sodium chloride till it passes a 30-mesh sieve, and then roasted in reverberatory furnaces. The chloridised product is extracted with water to remove unchanged salt and soluble compounds of cobalt, nickel, and copper. The copper is removed from the liquor by treatment with scrap-iron, and the cobalt and nickel are then precipitated with caustic soda, and the precipitate washed, dried, calcined, and ground. It contains about 40 per cent, of cobalt to 3 per cent, of nickel, since the latter is not attacked so readily as the former in chloridising the speiss the mixed oxides also contain about 15 ounces of silver per ton. 

PROP IDLH 10 mg/m (as Ni). CONSENSUS REPORTS NTP 10th Report on Carcinogens. Nickel and its compounds are on the Community Right-To-Know List. OSHA PEL TWA Soluble Compounds 0.1 mg(Ni)/m3 Insoluble Compounds 1 mg(Ni)/m3... 

The major health effect of nickel and its compounds is contact allergy and allergic contact dermatitis as a result of skin exposure to nickel ions, Ni(II). Inhalation exposure to soluble nickel and nickel oxides/sulfides has caused nasal and pulmonary cancer in workers in nickel refineries although there are no convincing data on carcinogenicity for metallic nickel dust in humans. Exposure to nickel or nickel compounds via routes other than inhalation has not been shown to increase the cancer risk in humans (Aitio 1995). Inhalation of nickel compounds may induce asthma however, nickel-induced asthma is rare. 

NICKEL. METAL AND SOLUBLE COMPOUNDS (AS Ni) Ni Synonyms vary depending upon specific compound Strong acids, sulfur, Ni(NOJ, wood, other combustibles Properties vary depending upon specific compound ... 

In electroless deposition, the substrate, prepared in the same manner as in electroplating (qv), is immersed in a solution containing the desired film components (see Electroless plating). The solutions generally used contain soluble nickel salts, hypophosphite, and organic compounds, and plating occurs by a spontaneous reduction of the metal ions by the hypophosphite at the substrate surface, which is presumed to catalyze the oxidation—reduction reaction. 

Metals less noble than copper, such as iron, nickel, and lead, dissolve from the anode. The lead precipitates as lead sulfate in the slimes. Other impurities such as arsenic, antimony, and bismuth remain partiy as insoluble compounds in the slimes and partiy as soluble complexes in the electrolyte. Precious metals, such as gold and silver, remain as metals in the anode slimes. The bulk of the slimes consist of particles of copper falling from the anode, and insoluble sulfides, selenides, or teUurides. These slimes are processed further for the recovery of the various constituents. Metals less noble than copper do not deposit but accumulate in solution. This requires periodic purification of the electrolyte to remove nickel sulfate, arsenic, and other impurities. 

Some nonmalignant respiratory effects have been observed in experimental animals during acute or subchronic exposures. Soluble and moderately soluble compounds were more toxic than were insoluble compounds and produced different effects. Sulfate and subsulftde produced fibrosis whereas nickel oxide did not. 

Dudley L.M., McNeal B.L., Baham J.E., Coray C.S., Cheng H.H. Characterization of soluble organic compounds and complexation of copper, nickel, and zinc in extracts of sludge-amended soils. J Environ Qual 1987 16 341-348. 

To protect humans and other mammals, proposed air-quality criteria range from 0.01 to less than 1.0 mg/m3 for metallic nickel and slightly soluble nickel compounds, 0.015-0.5 mg/m3 for water soluble nickel compounds, and 0.005 to 0.7 mg/m3 for nickel carbonyl (Table 6.10). Inhalation of nickel subsulfide concentrations (0.11 to 1.8 mg Ni/m3) near the current threshold limit value of 1 mg Ni/m3 can produce detrimental changes in the respiratory tract of rats after only a few days of exposure (Benson et al. 1995). Additional animal studies are recommended to identify minimally effective inhalation exposure levels for the various nickel compounds (USPHS 1993). Continued monitoring of nickel refining, nickel-cadmium battery manufacture, and nickel powder metallurgy installations is recommended because ambient air levels of bioavailable nickel at these... 

The linear telomerization reaction of dienes was one of the very first processes catalyzed by water soluble phosphine complexes in aqueous media [7,8]. The reaction itself is the dimerization of a diene coupled with a simultaneous nucleophilic addition of HX (water, alcohols, amines, carboxylic acids, active methylene compounds, etc.) (Scheme 7.3). It is catalyzed by nickel- and palladium complexes of which palladium catalysts are substantially more active. In organic solutions [Pd(OAc)2] + PPhs gives the simplest catalyst combination and Ni/IPPTS and Pd/TPPTS were suggested for mnning the telomerizations in aqueous/organic biphasic systems [7]. An aqueous solvent would seem a straightforward choice for telomerization of dienes with water (the so-called hydrodimerization). In fact, the possibility of separation of the products and the catalyst without a need for distillation is a more important reason in this case, too. 

Nickel is a silver-white, lustrous, hard, malleable, ductile, ferromagnetic metal that is relatively resistant to corrosion and is a fair conductor of heat and electricity. Nickel is a ubiquitous trace metal that occurs in soil, water, air, and in the biosphere. The average content in the earth s crust is about 0.008%. Nickel ore deposits are accumulations of nickel sulfide minerals (mostly pentlandite) and laterites. Nickel exists in five major forms elemental nickel and its alloys inorganic, water-soluble compounds (e.g., nickel chloride, nickel sulfate, and nickel nitrate) inorganic, water-insoluble compounds (e.g., nickel carbonate, nickel sulfide, and nickel oxide) organic, water-insoluble compounds and nickel carbonyl Ni(CO). ... 

Demet X procedure simply consists of an oxidation at elevated temperature, both the New Demet and the Demet III process has a sulfiding step which transforms the metal oxides to insoluble sulfides. In Demet III the sulfiding step is followed by a partial oxidation step. This oxidation is carefully controlled to produce metal sulfates and sulfides which can be directly removed by washing or be transferred into soluble compounds by the reductive and oxidative washes used in this procedure. In the New Demet process the sulfiding step is followed by chlorination which results in a transformation of the sulfides into washable chlorides. Since vanadium chlorides are volatile, most of the vanadium removal using this procedure occurs in the gas phase. In the Demet X procedure, the vanadium oxides formed are water soluble or can be transformed into water soluble forms by aqueous treatments. In contrast the nickel oxides are insoluble in water. 

Measurements of the amount of nickel in your blood, feces, and urine can be used to estimate your exposure to nickel. More nickel was found in the urine of workers who were exposed to nickel compounds that dissolve easily in water (soluble) than in the urine of workers exposed to compounds that are hard to dissolve (less-soluble). This means that it is easier to tell if you have been exposed to soluble compounds than less-soluble compounds. The nickel measurements do not accurately predict potential health effects from exposure to nickel. More information on medical tests can be found in Chapters 2 and 6. 

In humans, about 20-35% of the inhaled less-soluble nickel that is retained in the lungs is absorbed into the blood (Bennett 1984 Grandjean 1984 Sunderman and Oskarsson 1991). The remainder is either swallowed, expectorated, or remains in the respiratory tract. Nickel is detected in the urine of workers exposed to nickel (Angerer and Lehnert 1990 Elias et al. 1989 Ghezzi et al. 1989 Hassler et al. 1983 Toqussen and Andersen 1979). Higher concentrations of urinary nickel were found in workers exposed to soluble nickel compounds (nickel chloride, nickel sulfate) than in those exposed to less-soluble nickel compounds (nickel oxide, nickel subsulfide), indicating that the soluble compounds were more readily absorbed from the respiratory tract (Toijussen and Andersen 1979). A man that died of adult respiratory... 

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