Cobalt metal fume

Exposure to cobalt (metal fumes and dust) should be limited to 0.05 mg/ms (8-hour time-weighted average 40-hour week). 

S203 Cobalt metal fume dust 0.1 MCEF Aqua regia AA 0. 031-0.22 (f)... 

SYNONYMS Cobalt oxide, cobalt chloride, aquacat, cobalt metal, fume and dust, cobalt carbonyl, cobalt hydrocarbonyl, synonyms vary by compound. 

SYNONYMS aquacat, cobalt metal dust, cobalt metal fume, super cobalt. 

Cobalt is a brittle, hard metal, resembling iron and nickel in appearance. It has a metallic permeability of about two-thirds that of iron. The transformation is slnggish and accounts in part for the wide variation in reported data on physical properties of cobalt. Exposure to cobalt (metal fumes and dust) should be limited to 0.05 mg/m (8-hour time-weighted average in a 40-hour week). 

Synonyms/Trade Names Cobalt metal dust, Cobalt metal fume... 

COBALT METAL. FUME. AND DUST (AS CO) Co Synonyms vary depending upon spccifk compound Strong oxidizers NA NA NA... 

Coal tar pitch volatiles, see Particulate polycyclic aromatic hydrocarbons (PPAH), as benzene solubles Cobalt metal, dust and fume (as Co)... 

Bartholomew and coworkers32 described deactivation of cobalt catalysts supported on fumed silica and on silica gel. Rapid deactivation was linked with high conversions, and the activity was not recovered by oxidation and re-reduction of the catalysts, indicating that carbon deposition was not responsible for the loss of activity. Based on characterization of catalysts used in the FTS and steam-treated catalysts and supports the authors propose that the deactivation is due to support sintering in steam (loss of surface area and increased pore diameter) as well as loss of cobalt metal surface area. The mechanism of the latter is suggested to be due to the formation of cobalt silicates or encapsulation of the cobalt metal by the collapsing support. 

Cobalt metal with tungsten carbide fumes... 

Aquacat C.l. 77320 CCRIS 1575 Cobalt Cobalt-59 Cobalt, elemental Cobalt fume Cobalt metal, dust and fume Cobalt metal powder EINECS 231-158-0 HSDB 519 Kobalt NCI-C60311 Super cobalt. Oxidizing agent, lamp filaments, in manufacture of cobalt steel in porcelain, glass, pottery, enamels. Atomergic Chemetals Cerac Noah Chem. Sigma-Aldrich Fine Chem. 

EXPOSURE GUIDELINES ACGIH TLV TWA (cobalt metal, dust and fume) 0.02 mg/m OSHA PEL TWA (cobalt metal, dust and fume) O.lmg/m NIOSH REL TWA (cobalt metal, dust and fume) 0.05mg/m IDLH (cobalt metal, dust and fume) 20mg/m . 

Two C0/S1O2 catalysts, one supported on silica gel (Grace Davison Grade 654) and the other supported on fumed silica (Cab-O-sil M-5) were prepared by a non-aqueous (acetone) evaporative deposition. The cobalt metal loading was 11 wt. % for both catalysts. Details of the preparation method are discussed elsewhere [22, 23]. 

Gravimetric Methods.—The main difficulty is to obtain the cobalt in the form of one of its compounds entirely free from nickel or other metal. This may be accomplished by the cyanide method described under Wet Tests above. The solution, after separation of the nickel, is evaporated with dilute sulphuric acid until white fumes are evolved. On addition of water a solution of cobalt sulphate results, and the cobalt may be precipitated in a variety of ways, for example as oxide with hypobromites or persulphates,2 as sulphide, as cobalti-nitroso p-naphthol, or as basic carbonate.3 In each case the precipitate is ignited and reduced to metallic cobalt in a current of pure hydrogen. 

Other experimental reproductive effects. A skin and severe eye irritant. A narcotic. Human mutation data reported. A common air contaminant. Highly flammable liquid. NCxmres of 30-60% of the vapor in air ignite above 100°. It can react violently with acid anhydrides, alcohols, ketones, phenols, NH3, HCN, H2S, halogens, P, isocyanates, strong alkalies, and amines. Reactions with cobalt chloride, mercury(II) chlorate, or mercury(II) perchlorate form violendy in the presence of traces of metals or acids. Reaction with oxygen may lead to detonation. When heated to decomposition it emits acrid smoke and fumes. 

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